1
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Rieland L, Wagner J, Bernhardt R, Wang T, Abdul-Aziz O, Stein P, Pogna EAA, Dal Conte S, Cerullo G, Hedayat H, van Loosdrecht PHM. Ultrafast Optical Control of Exciton Diffusion in WSe 2/Graphene Heterostructures Revealed by Heterodyne Transient Grating Spectroscopy. NANO LETTERS 2024; 24:9824-9831. [PMID: 39056490 DOI: 10.1021/acs.nanolett.4c01516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
Using heterodyne transient grating spectroscopy, we observe a significant enhancement of exciton diffusion in a monolayer WSe2 stacked on graphene. The diffusion dynamics can be optically tuned within a few picoseconds by altering the photoexcited carrier density in graphene. The effective diffusion constant in initial picoseconds in the WSe2/graphene heterostructure is (40.3 ± 4.5) cm2 s-1, representing a substantial improvement over (2.1 ± 0.8) cm2 s-1, typical for an isolated WSe2 monolayer. This enhancement can be understood in terms of a transient screening of impurities, charge traps, and defect states in WSe2 by photoexcited charge carriers in graphene. Furthermore, diffusion within WSe2 is affected by interlayer interactions, such as charge transfer, varying with the incident excitation fluence. These findings underscore the dynamical nature of screening and diffusion processes in heterostructures of 2D semiconductors and graphene and provide insights for future applications of these systems in ultrafast optoelectronic devices.
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Affiliation(s)
- Lukas Rieland
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, Köln D-50937, Germany
| | - Julian Wagner
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, Köln D-50937, Germany
| | - Robin Bernhardt
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, Köln D-50937, Germany
| | - Tianyi Wang
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, Köln D-50937, Germany
| | - Omar Abdul-Aziz
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, Köln D-50937, Germany
| | - Philipp Stein
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, Köln D-50937, Germany
| | - Eva A A Pogna
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza L. da Vinci 32, 20133 Milano, Italy
| | - Stefano Dal Conte
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milan, Italy
| | - Giulio Cerullo
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza L. da Vinci 32, 20133 Milano, Italy
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milan, Italy
| | - Hamoon Hedayat
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, Köln D-50937, Germany
| | - Paul H M van Loosdrecht
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, Köln D-50937, Germany
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2
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Dai Y, Tao G, Chen Y, Yao G, Liu D, Dang Z, Liu Z, Peng P, Huang Y, He X, Zhang H, Zheng Z, Sun H, Qian W, Qi P, Gong Y, Guan Y, Liu K, Fang Z. Two-Dimensional Exciton Oriented Diffusion via Periodic Potentials. ACS NANO 2024. [PMID: 39141918 DOI: 10.1021/acsnano.4c05723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/16/2024]
Abstract
Excitonic devices operate based on excitons, which can be excited by photons as well as emitting photons and serve as a medium for photon-carrier conversion. Excitonic devices are expected to combine the advantages of both the high response rate of photonic devices and the high integration of electronic devices simultaneously. However, because of the neutral feature, exciton transport is generally achieved via diffusion rather than using electric fields, and the efficient control of exciton flux directionality has always been difficult. In this work, a precisely designed one-dimensional periodic nanostructure (1DPS) is used to introduce periodic strain field along with resonant mode to the WS2 monolayer, achieving exciton oriented diffusion with a 7.6-fold exciton diffusion coefficient enhancement relative to that of intrinsic, while enhancing the excitonic emission intensity by a factor of 10 and reducing exciton saturation threshold power by 2 orders of magnitude. Based on the analysis of the density functional theory (DFT) and the finite-element method (FEM), we attribute the anisotropy of exciton diffusion to exciton funneling induced by periodic potentials, which do not require excessive potential height difference for an efficient oriented diffusion. As a result of resonant emission, the exciton diffusion is dragged into the nonlinear regime owing to the high exciton density close to saturation, which improves the exciton diffusion coefficient and diffusion anisotropy more appreciably.
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Affiliation(s)
- Yuchen Dai
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Guangyi Tao
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Yuxiang Chen
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Guangjie Yao
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Donglin Liu
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Zhibo Dang
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Zhengchang Liu
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Pu Peng
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Yijing Huang
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Xiao He
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Han Zhang
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Zhipeng Zheng
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Haonan Sun
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Wenqi Qian
- Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Institute of Modern Optics, Nankai University, Tianjin 300350, China
| | - Pengfei Qi
- Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Institute of Modern Optics, Nankai University, Tianjin 300350, China
| | - Yongji Gong
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Yan Guan
- Center for Physicochemical Analysis and Measurements in ICCAS, Analytical Instrumentation Center, Peking University, Beijing 100871, China
| | - Kaihui Liu
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
| | - Zheyu Fang
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
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3
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Karmakar A, Al-Mahboob A, Zawadzka N, Raczyński M, Yang W, Arfaoui M, Gayatri, Kucharek J, Sadowski JT, Shin HS, Babiński A, Pacuski W, Kazimierczuk T, Molas MR. Twisted MoSe 2 Homobilayer Behaving as a Heterobilayer. NANO LETTERS 2024; 24:9459-9467. [PMID: 39042710 PMCID: PMC11311526 DOI: 10.1021/acs.nanolett.4c01764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Revised: 07/11/2024] [Accepted: 07/11/2024] [Indexed: 07/25/2024]
Abstract
Heterostructures (HSs) formed by the transition-metal dichalcogenide materials have shown great promise in next-generation (opto)electronic applications. An artificially twisted HS allows us to manipulate the optical and electronic properties. In this work, we introduce the understanding of the energy transfer (ET) process governed by the dipolar interaction in a twisted molybdenum diselenide (MoSe2) homobilayer without any charge-blocking interlayer. We fabricated an unconventional homobilayer (i.e., HS) with a large twist angle (∼57°) by combining the chemical vapor deposition (CVD) and mechanical exfoliation (Exf.) techniques to fully exploit the lattice parameter mismatch and indirect/direct (CVD/Exf.) bandgap nature. These effectively weaken the interlayer charge transfer and allow the ET to control the carrier recombination channels. Our experimental and theoretical results explain a massive HS photoluminescence enhancement due to an efficient ET process. This work shows that the electronically decoupled MoSe2 homobilayer is coupled by the ET process, mimicking a "true" heterobilayer nature.
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Affiliation(s)
- Arka Karmakar
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Abdullah Al-Mahboob
- Center
for Functional Nanomaterials, Brookhaven
National Laboratory, Upton, New York 11973, United States
| | - Natalia Zawadzka
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Mateusz Raczyński
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Weiguang Yang
- Department
of Chemistry, Ulsan National Institute of
Science and Technology, Ulsan 44919, Republic
of Korea
| | - Mehdi Arfaoui
- Département
de Physique, Faculté des Sciences de Tunis, Université Tunis El Manar, Campus Universitaire, 1060 Tunis, Tunisia
| | - Gayatri
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Julia Kucharek
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Jerzy T. Sadowski
- Center
for Functional Nanomaterials, Brookhaven
National Laboratory, Upton, New York 11973, United States
| | - Hyeon Suk Shin
- Department
of Chemistry, Ulsan National Institute of
Science and Technology, Ulsan 44919, Republic
of Korea
- Center
for 2D Quantum Heterostructures, Institute
for Basic Science (IBS), Suwon 16419, Republic
of Korea
- Department
of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Adam Babiński
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Wojciech Pacuski
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Tomasz Kazimierczuk
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Maciej R. Molas
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
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4
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Poudyal S, Deka M, Adhikary P, D R, Barman PK, Yadav R, Biswal B, Rajarapu R, Mukherjee S, Nanda BRK, Singh A, Misra A. Room Temperature, Twist Angle Independent, Momentum Direct Interlayer Excitons in van der Waals Heterostructures with Wide Spectral Tunability. NANO LETTERS 2024; 24:9575-9582. [PMID: 39051155 DOI: 10.1021/acs.nanolett.4c02180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
Interlayer excitons (IXs) in van der Waals heterostructures with static out of plane dipole moment and long lifetime show promise in the development of exciton based optoelectronic devices and the exploration of many body physics. However, these IXs are not always observed, as the emission is very sensitive to lattice mismatch and twist angle between the constituent materials. Moreover, their emission intensity is very weak compared to that of corresponding intralayer excitons at room temperature. Here we report the room-temperature realization of twist angle independent momentum direct IX in the heterostructures of bulk PbI2 and bilayer WS2. Momentum conserving transitions combined with the large band offsets between the constituent materials enable intense IX emission at room temperature. A long lifetime (∼100 ns), noticeable Stark shift, and tunability of IX emission from 1.70 to 1.45 eV by varying the number of WS2 layers make these heterostructures promising to develop room temperature exciton based optoelectronic devices.
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Affiliation(s)
- Saroj Poudyal
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
- Center for 2D Materials Research and Innovation, IIT Madras, Chennai 600036, India
| | - Mrinal Deka
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
- Center for 2D Materials Research and Innovation, IIT Madras, Chennai 600036, India
| | - Priyo Adhikary
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - Ranju D
- Department of Physics, Indian Institute of Science, Bengaluru, Karnataka 560012, India
| | - Prahalad Kanti Barman
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
- Center for 2D Materials Research and Innovation, IIT Madras, Chennai 600036, India
| | - Renu Yadav
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
- Center for 2D Materials Research and Innovation, IIT Madras, Chennai 600036, India
| | - Bubunu Biswal
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
- Center for 2D Materials Research and Innovation, IIT Madras, Chennai 600036, India
- Center for Atomistic Modelling and Materials Design, IIT Madras, Chennai 600036, India
| | - Ramesh Rajarapu
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
- Center for 2D Materials Research and Innovation, IIT Madras, Chennai 600036, India
| | - Shantanu Mukherjee
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - Birabar Ranjit Kumar Nanda
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
- Center for Atomistic Modelling and Materials Design, IIT Madras, Chennai 600036, India
| | - Akshay Singh
- Department of Physics, Indian Institute of Science, Bengaluru, Karnataka 560012, India
| | - Abhishek Misra
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
- Center for 2D Materials Research and Innovation, IIT Madras, Chennai 600036, India
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5
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Chen D, Dini K, Rasmita A, Huang Z, Tan Q, Cai H, He R, Miao Y, Liew TCH, Gao W. Spatial Filtering of Interlayer Exciton Ground State in WSe 2/MoS 2 Heterobilayer. NANO LETTERS 2024; 24:8795-8800. [PMID: 38985646 DOI: 10.1021/acs.nanolett.4c00767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2024]
Abstract
Long-life interlayer excitons (IXs) in transition metal dichalcogenide (TMD) heterostructure are promising for realizing excitonic condensates at high temperatures. Critical to this objective is to separate the IX ground state (the lowest energy of IX state) emission from other states' emissions. Filtering the IX ground state is also essential in uncovering the dynamics of correlated excitonic states, such as the excitonic Mott insulator. Here, we show that the IX ground state in the WSe2/MoS2 heterobilayer can be separated from other states by its spatial profile. The emissions from different moiré IX modes are identified by their different energies and spatial distributions, which fits well with the rate-diffusion model for cascading emission. Our results show spatial filtering of the ground state mode and enrich the toolbox to realize correlated states at elevated temperatures.
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Affiliation(s)
- Disheng Chen
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637371, Singapore
| | - Kevin Dini
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Abdullah Rasmita
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Zumeng Huang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Qinghai Tan
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637371, Singapore
| | - Hongbing Cai
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637371, Singapore
| | - Ruihua He
- Institute For Digital Molecular Analytics and Science, Nanyang Technological University, Singapore 636921, Singapore
| | - Yansong Miao
- Institute For Digital Molecular Analytics and Science, Nanyang Technological University, Singapore 636921, Singapore
| | - Timothy C H Liew
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- MajuLab, International Joint Research Unit UMI 3654, CNRS, Université Côte d'Azur, Sorbonne Université, National University of Singapore, Nanyang Technological University, Singapore 637371, Singapore
| | - Weibo Gao
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637371, Singapore
- MajuLab, International Joint Research Unit UMI 3654, CNRS, Université Côte d'Azur, Sorbonne Université, National University of Singapore, Nanyang Technological University, Singapore 637371, Singapore
- Centre for Quantum Technologies, National University of Singapore, Singapore 117543, Singapore
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6
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Wu K, Yang Z, Shi Y, Wang Y, Xiang B, Zhou H, Chen W, Zhang S, Xu H, Xiong Q. Revealing the Optical Transition Properties of Interlayer Excitons in Defective WS 2/WSe 2 Heterobilayers. NANO LETTERS 2024; 24:8671-8678. [PMID: 38975929 DOI: 10.1021/acs.nanolett.4c02025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
Manipulation of physical properties in multidimensional tunable moiré superlattice systems is a key focus in nanophotonics, especially for interlayer excitons (IXs) in two-dimensional materials. However, the impact of defects on IXs remains unclear. Here, we thoroughly study the optical properties of WS2/WSe2 heterobilayers with varying defect densities. Low-temperature photoluminescence (PL) characterizations reveal that the low-energy IXs are more susceptible to defects compared to the high-energy IXs. The low-energy IXs also show much faster PL quenching rate with temperature, faster peak width broadening rate with laser power, shorter lifetime, and lower circular polarization compared to the low-energy IXs in the region with fewer defects. These effects are attributed to the combined effects of increased electron scattering, exciton-phonon interactions, and nonradiative channels introduced by the defects. Our findings aid in optimizing moiré superlattice structures.
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Affiliation(s)
- Ke Wu
- School of Sciences, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Ziyi Yang
- School of Sciences, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Yanwei Shi
- School of Sciences, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Yubin Wang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Baixu Xiang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Hongzhi Zhou
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311200, Zhejiang, China
| | - Wen Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Shunping Zhang
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
- Wuhan Institute of Quantum Technology, Wuhan 430206, China
| | - Hongxing Xu
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
- Institute of Quantum Materials and Physics, Henan Academy of Sciences, Zhengzhou 450046, China
| | - Qihua Xiong
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
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7
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Rossi A, Zipfel J, Maity I, Lorenzon M, Dandu M, Barré E, Francaviglia L, Regan EC, Zhang Z, Nie JH, Barnard ES, Watanabe K, Taniguchi T, Rotenberg E, Wang F, Lischner J, Raja A, Weber-Bargioni A. Anomalous Interlayer Exciton Diffusion in WS 2/WSe 2 Moiré Heterostructure. ACS NANO 2024; 18:18202-18210. [PMID: 38950893 PMCID: PMC11256890 DOI: 10.1021/acsnano.4c00015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 05/28/2024] [Accepted: 06/05/2024] [Indexed: 07/03/2024]
Abstract
Stacking van der Waals crystals allows for the on-demand creation of a periodic potential landscape to tailor the transport of quasiparticle excitations. We investigate the diffusion of photoexcited electron-hole pairs, or excitons, at the interface of WS2/WSe2 van der Waals heterostructure over a wide range of temperatures. We observe the appearance of distinct interlayer excitons for parallel and antiparallel stacking and track their diffusion through spatially and temporally resolved photoluminescence spectroscopy from 30 to 250 K. While the measured exciton diffusivity decreases with temperature, it surprisingly plateaus below 90 K. Our observations cannot be explained by classical models like hopping in the moiré potential. A combination of ab initio theory and molecular dynamics simulations suggests that low-energy phonons arising from the mismatched lattices of moiré heterostructures, also known as phasons, play a key role in describing and understanding this anomalous behavior of exciton diffusion. Our observations indicate that the moiré potential landscape is dynamic down to very low temperatures and that the phason modes can enable efficient transport of energy in the form of excitons.
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Affiliation(s)
- Antonio Rossi
- The
Molecular Foundry, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
- Advanced
Light Source, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
- Center
for Nanotechnology Innovation @ NEST, Instituto
Italiano di Tecnologia, 56127 Pisa, Italy
| | - Jonas Zipfel
- The
Molecular Foundry, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Indrajit Maity
- Imperial
College London, South Kensington Campus, London SW7 2AZ, U.K.
| | - Monica Lorenzon
- The
Molecular Foundry, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Medha Dandu
- The
Molecular Foundry, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Elyse Barré
- The
Molecular Foundry, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Luca Francaviglia
- The
Molecular Foundry, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Emma C. Regan
- Department
of Physics, University of California at
Berkeley, Berkeley, California 94720, United States
| | - Zuocheng Zhang
- Department
of Physics, University of California at
Berkeley, Berkeley, California 94720, United States
| | - Jacob H. Nie
- Department
of Physics, University of California at
Berkeley, Berkeley, California 94720, United States
- Department
of Physics, University of California at
Santa Barbara, Santa
Barbara, California 93106, United States
| | - Edward S. Barnard
- The
Molecular Foundry, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Kenji Watanabe
- Research
Center for Functional Materials, National
Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0047, Japan
| | - Takashi Taniguchi
- International
Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0047, Japan
| | - Eli Rotenberg
- Advanced
Light Source, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Feng Wang
- Department
of Physics, University of California at
Berkeley, Berkeley, California 94720, United States
| | - Johannes Lischner
- Imperial
College London, South Kensington Campus, London SW7 2AZ, U.K.
| | - Archana Raja
- The
Molecular Foundry, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Alexander Weber-Bargioni
- The
Molecular Foundry, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
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8
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Ju Q, Cai Q, Jian C, Hong W, Sun F, Wang B, Liu W. Infrared Interlayer Excitons in Twist-Free MoTe 2/MoS 2 Heterobilayers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2404371. [PMID: 39007276 DOI: 10.1002/adma.202404371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 06/13/2024] [Indexed: 07/16/2024]
Abstract
Excitonic devices based on interlayer excitons in van der Waals heterobilayers are a promising platform for advancing photoelectric interconnection telecommunications. However, the absence of exciton emission in the crucial telecom C-band has constrained their practical applications. Here, this limitation is addressed by reporting exciton emission at 0.8 eV (1550 nm) in a chemically vapor-deposited, strictly aligned MoTe2/MoS2 heterobilayer, resulting from the direct bandgap transitions of interlayer excitons as identified by momentum-space imaging of their electrons and holes. The decay mechanisms dominated by direct radiative recombination ensure constant emission quantum yields, a basic demand for efficient excitonic devices. The atomically sharp interface enables the resolution of two narrowly-splitter transitions induced by spin-orbit coupling, further distinguished through the distinct Landé g-factors as the fingerprint of spin configurations. By electrical control, the double transitions coupling into opposite circularly-polarized photon modes, preserve or reverse the helicities of the incident light with a degree of polarization up to 90%. The Stark effect tuning extends the emission energy range by over 150 meV (270 nm), covering the telecom C-band. The findings provide a material platform for studying the excitonic complexes and significantly boost the application prospects of excitonic devices in silicon photonics and all-optical telecommunications.
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Affiliation(s)
- Qiankun Ju
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Provincial Key Laboratory of Materials and Techniques toward Hydrogen Energy, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Qian Cai
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Provincial Key Laboratory of Materials and Techniques toward Hydrogen Energy, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China
| | - Chuanyong Jian
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Provincial Key Laboratory of Materials and Techniques toward Hydrogen Energy, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China
| | - Wenting Hong
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Provincial Key Laboratory of Materials and Techniques toward Hydrogen Energy, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China
| | - Fapeng Sun
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Provincial Key Laboratory of Materials and Techniques toward Hydrogen Energy, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Bicheng Wang
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Provincial Key Laboratory of Materials and Techniques toward Hydrogen Energy, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China
| | - Wei Liu
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Provincial Key Laboratory of Materials and Techniques toward Hydrogen Energy, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian, 350108, P. R. China
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9
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Zhang D, Ge C, Wang Y, Xia Y, Zhao H, Yao C, Chen Y, Ma C, Tong Q, Pan A, Wang X. Enhancing Layer-Engineered Interlayer Exciton Emission and Valley Polarization in van der Waals Heterostructures via Strain. ACS NANO 2024; 18:17672-17680. [PMID: 38920321 DOI: 10.1021/acsnano.4c02377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
Layer-engineered interlayer excitons from heterostructures of transition-metal dichalcogenides (TMDCs) exhibit a rich variety of emissive states and intriguing valley spin-selection rules, the effective modulation of which is crucial for excitonic physics and related device applications. Strain or high pressure provides the possibility to tune the energy of the interlayer excitons; however, the reported emission intensity is substantially quenched, which greatly limits their practical application in optoelectronic devices. Here, via applying uniaxial strain based on polyvinyl alcohol (PVA) encapsulation technique, we report enhanced layer-engineered interlayer exciton emission intensity with largely modulated emission energy in WSe2/WS2 heterobilayer and heterotrilayer. Both momentum-direct and momentum-indirect interlayer excitons were observed, and their emission energies show an opposite shift tendency upon applied strain, which agrees with our DFT calculations. We further demonstrate that intralayer and interlayer exciton states with low phonon interactions can be modulated through the mechanical strain applied to the PVA substrate at low temperatures. Due to strain-induced breaking of the 3-fold rotational symmetry, we observe the enhanced valley polarization of interlayer excitons. Our study contributes to the understanding and modulation of the optical properties of interlayer excitons, which could be exploited for optoelectronic device applications.
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Affiliation(s)
- Danliang Zhang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Cuihuang Ge
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Youwen Wang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Yang Xia
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Haipeng Zhao
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Chengdong Yao
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Ying Chen
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Chao Ma
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Qingjun Tong
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Anlian Pan
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Xiao Wang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
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10
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Xu H, Wang J, Liu H, Chen S, Sun Z, Wang C, Han R, Wang Y, Wang Y, Wang Z, Huang S, Ma L, Liu D. Control of Hybrid Exciton Lifetime in MoSe 2/WS 2 Moiré Heterostructures. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2403127. [PMID: 38970212 DOI: 10.1002/advs.202403127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 06/12/2024] [Indexed: 07/08/2024]
Abstract
Hybrid excitons, characterized by their strong oscillation strength and long lifetimes, hold great potential as information carriers in semiconductors. They offer promising applications in exciton-based devices and circuits. MoSe2/WS2 heterostructures represent an ideal platform for studying hybrid excitons, but how to regulate the exciton lifetime has not yet been explored. In this study, layer hybridization is modulated by applying electric fields parallel or antiparallel to the dipole moment, enabling us to regulate the exciton lifetime from 1.36 to 4.60 ns. Furthermore, the time-resolved photoluminescence decay traces are measured at different excitation power. A hybrid exciton annihilation rate of 8.9 × 10-4 cm2 s-1 is obtained by fitting. This work reveals the effects of electric fields and excitation power on the lifetime of hybrid excitons in MoSe2/WS2 1.5° moiré heterostructures, which play important roles in high photoluminescence quantum yield optoelectronic devices based on transition-metal dichalcogenides heterostructures.
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Affiliation(s)
- Haowen Xu
- Institue for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China
| | - Jiangcai Wang
- State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
| | - Huan Liu
- State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
| | - Shihong Chen
- School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China
| | - Zejun Sun
- State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
| | - Chong Wang
- State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
| | - Rui Han
- State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
| | - Yong Wang
- Laboratory of Optical Detection and Imaging, School of Science, Qingdao University of Technology, Qingdao, 266033, China
| | - Yutang Wang
- School of Mechanical Engineering and Automation, Northeastern University, Shenyang, 110819, China
| | - Zihao Wang
- School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China
| | - Shuchun Huang
- State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
| | - Lingwei Ma
- Institue for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China
| | - Dameng Liu
- State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
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11
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Zhou Z, Zhu J, Li L, Wang C, Zhang C, Du X, Wang X, Zhao G, Wang R, Li J, Lu Z, Zong Y, Sun Y, Rümmeli MH, Zou G. Monomolecular Membrane-Assisted Growth of Antimony Halide Perovskite/MoS 2 Van der Waals Epitaxial Heterojunctions with Long-Lived Interlayer Exciton. ACS NANO 2024; 18:17282-17292. [PMID: 38904992 DOI: 10.1021/acsnano.4c05293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Epitaxial growth stands as a key method for integrating semiconductors into heterostructures, offering a potent avenue to explore the electronic and optoelectronic characteristics of cutting-edge materials, such as transition metal dichalcogenide (TMD) and perovskites. Nevertheless, the layer-by-layer growth atop TMD materials confronts a substantial energy barrier, impeding the adsorption and nucleation of perovskite atoms on the 2D surface. Here, we epitaxially grown an inorganic lead-free perovskite on TMD and formed van der Waals (vdW) heterojunctions. Our work employs a monomolecular membrane-assisted growth strategy that reduces the contact angle and simultaneously diminishing the energy barrier for Cs3Sb2Br9 surface nucleation. By controlling the nucleation temperature, we achieved a reduction in the thickness of the Cs3Sb2Br9 epitaxial layer from 30 to approximately 4 nm. In the realm of inorganic lead-free perovskite and TMD heterojunctions, we observed long-lived interlayer exciton of 9.9 ns, approximately 36 times longer than the intralayer exciton lifetime, which benefited from the excellent interlayer coupling brought by direct epitaxial growth. Our research introduces a monomolecular membrane-assisted growth strategy that expands the diversity of materials attainable through vdW epitaxial growth, potentially contributing to future applications in optoelectronics involving heterojunctions.
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Affiliation(s)
- Zhicheng Zhou
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou 215123, China
| | - Juntong Zhu
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
| | - Lutao Li
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
| | - Chen Wang
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
| | - Changwen Zhang
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
| | - Xinyu Du
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
| | - Xiangyi Wang
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
| | - Guoxiang Zhao
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou 215123, China
| | - Ruonan Wang
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
| | - Jiating Li
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
| | - Zheng Lu
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
| | - Yi Zong
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou Jiangsu 215123, China
| | - Yinghui Sun
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
| | - Mark H Rümmeli
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou 215123, China
- Institute for Complex Materials, IFW Dresden, 20 Helmholtz Strasse Dresden 01069, Germany
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences, M. Curie-Sklodowskiej 34 Zabrze 41-819, Poland
- Institute of Environmental Technology, VSB-Technical University of Ostrava,17. Listopadu 15 Ostrava 70833, Czech Republic
| | - Guifu Zou
- College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China
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12
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Liu Y, Dai F, Bai H, Fan X, Wang R, Zheng X, Xiong Z, Sun H, Liang Z, Kang Z, Zhang Y. Exciton Localization Modulated by Ultradeep Moiré Potential in Twisted Bilayer γ-Graphdiyne. J Am Chem Soc 2024; 146:14593-14599. [PMID: 38718194 DOI: 10.1021/jacs.4c01359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Twisted moiré superlattice is featured with its moiré potential energy, the depth of which renders an effective approach to strengthening the exciton-exciton interaction and exciton localization toward high-performance quantum photonic devices. However, it remains as a long-standing challenge to further push the limit of moiré potential depth. Herein, owing to the pz orbital induced band edge states enabled by the unique sp-C in bilayer γ-graphdiyne (GDY), an ultradeep moiré potential of ∼289 meV is yielded. After being twisted into the hole-to-hole layer stacking configuration, the interlayer coupling is substantially intensified to augment the lattice potential of bilayer GDY up to 475%. The presence of lateral constrained moiré potential shifts the spatial distribution of electrons and holes in excitons from the regular alternating mode to their respective separated and localized mode. According to the well-established wave function distribution of electrons contained in excitons, the AA-stacked site is identified to serve for exciton localization. This work extends the materials systems available for moiré superlattice design further to serial carbon allotropes featured with benzene ring-alkyne chain coupling, unlocking tremendous potential for twistronic-based quantum device applications.
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Affiliation(s)
- Yingcong Liu
- Academy for Advanced Interdisciplinary Science and Technology, Beijing Key Laboratory for Advanced Energy Materials and Technologies, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of Education, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Fulong Dai
- Academy for Advanced Interdisciplinary Science and Technology, Beijing Key Laboratory for Advanced Energy Materials and Technologies, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of Education, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Haokun Bai
- Academy for Advanced Interdisciplinary Science and Technology, Beijing Key Laboratory for Advanced Energy Materials and Technologies, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of Education, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Xiayue Fan
- Academy for Advanced Interdisciplinary Science and Technology, Beijing Key Laboratory for Advanced Energy Materials and Technologies, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of Education, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Ruiqi Wang
- Academy for Advanced Interdisciplinary Science and Technology, Beijing Key Laboratory for Advanced Energy Materials and Technologies, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of Education, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Xuzhi Zheng
- Academy for Advanced Interdisciplinary Science and Technology, Beijing Key Laboratory for Advanced Energy Materials and Technologies, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of Education, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Zhaozhao Xiong
- Academy for Advanced Interdisciplinary Science and Technology, Beijing Key Laboratory for Advanced Energy Materials and Technologies, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of Education, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Haochun Sun
- Academy for Advanced Interdisciplinary Science and Technology, Beijing Key Laboratory for Advanced Energy Materials and Technologies, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of Education, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Zhuojian Liang
- Academy for Advanced Interdisciplinary Science and Technology, Beijing Key Laboratory for Advanced Energy Materials and Technologies, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of Education, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Zhuo Kang
- Academy for Advanced Interdisciplinary Science and Technology, Beijing Key Laboratory for Advanced Energy Materials and Technologies, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of Education, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Yue Zhang
- Academy for Advanced Interdisciplinary Science and Technology, Beijing Key Laboratory for Advanced Energy Materials and Technologies, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of Education, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
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13
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Zhang L, Gu L, Ni R, Xie M, Park S, Jang H, Ma R, Taniguchi T, Watanabe K, Zhou Y. Electrical Control and Transport of Tightly Bound Interlayer Excitons in a MoSe_{2}/hBN/MoSe_{2} Heterostructure. PHYSICAL REVIEW LETTERS 2024; 132:216903. [PMID: 38856288 DOI: 10.1103/physrevlett.132.216903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 03/11/2024] [Accepted: 04/15/2024] [Indexed: 06/11/2024]
Abstract
Controlling interlayer excitons in Van der Waals heterostructures holds promise for exploring Bose-Einstein condensates and developing novel optoelectronic applications, such as excitonic integrated circuits. Despite intensive studies, several key fundamental properties of interlayer excitons, such as their binding energies and interactions with charges, remain not well understood. Here we report the formation of momentum-direct interlayer excitons in a high-quality MoSe_{2}/hBN/MoSe_{2} heterostructure under an electric field, characterized by bright photoluminescence (PL) emission with high quantum yield and a narrow linewidth of less than 4 meV. These interlayer excitons show electrically tunable emission energy spanning ∼180 meV through the Stark effect, and exhibit a sizable binding energy of ∼81 meV in the intrinsic regime, along with trion binding energies of a few millielectronvolts. Remarkably, we demonstrate the long-range transport of interlayer excitons with a characteristic diffusion length exceeding 10 μm, which can be attributed, in part, to their dipolar repulsive interactions. Spatially and polarization-resolved spectroscopic studies reveal rich exciton physics in the system, such as valley polarization, local trapping, and the possible existence of dark interlayer excitons. The formation and transport of tightly bound interlayer excitons with narrow linewidth, coupled with the ability to electrically manipulate their properties, open exciting new avenues for exploring quantum many-body physics, including excitonic condensate and superfluidity, and for developing novel optoelectronic devices, such as exciton and photon routers.
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Affiliation(s)
- Lifu Zhang
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Liuxin Gu
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Ruihao Ni
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Ming Xie
- Condensed Matter Theory Center, University of Maryland, College Park, Maryland 20742, USA
| | - Suji Park
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Houk Jang
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Rundong Ma
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Takashi Taniguchi
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Kenji Watanabe
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - You Zhou
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
- Maryland Quantum Materials Center, College Park, Maryland 20742, USA
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14
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Huang TS, Lunts P, Hafezi M. Nonbosonic Moiré Excitons. PHYSICAL REVIEW LETTERS 2024; 132:186202. [PMID: 38759194 DOI: 10.1103/physrevlett.132.186202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 04/09/2024] [Indexed: 05/19/2024]
Abstract
Optical excitations in moiré transition metal dichalcogenide bilayers lead to the creation of excitons, as electron-hole bound states, that are generically considered within a Bose-Hubbard framework. Here, we demonstrate that these composite particles obey an angular momentum commutation relation that is generally nonbosonic. This emergent spin description of excitons indicates a limitation to their occupancy on each site, which is substantial in the weak electron-hole binding regime. The effective exciton theory is accordingly a spin Hamiltonian, which further becomes a Hubbard model of emergent bosons subject to an occupancy constraint after a Holstein-Primakoff transformation. We apply our theory to three commonly studied bilayers (MoSe_{2}/WSe_{2}, WSe_{2}/WS_{2}, and WSe_{2}/MoS_{2}) and show that in the relevant parameter regimes their allowed occupancies never exceed three excitons. Our systematic theory provides guidelines for future research on the many-body physics of moiré excitons.
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Affiliation(s)
- Tsung-Sheng Huang
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
| | - Peter Lunts
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Mohammad Hafezi
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
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15
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Zhu Y, Shi Z, Zhao Y, Bu S, Hu Z, Liao J, Lu Q, Zhou C, Guo B, Shang M, Li F, Xu Z, Zhang J, Xie Q, Li C, Sun P, Mao B, Zhang X, Liu Z, Lin L. Recent trends in the transfer of graphene films. NANOSCALE 2024; 16:7862-7873. [PMID: 38568087 DOI: 10.1039/d3nr05626k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Recent years have witnessed advances in chemical vapor deposition growth of graphene films on metal foils with fine scalability and thickness controllability. However, challenges for obtaining wrinkle-free, defect-free and large-area uniformity remain to be tackled. In addition, the real commercial applications of graphene films still require industrially compatible transfer techniques with reliable performance of transferred graphene, excellent production capacity, and suitable cost. Transferred graphene films, particularly with a large area, still suffer from the presence of transfer-related cracks, wrinkles and contaminants, which would strongly deteriorate the quality and uniformity of transferred graphene films. Potential applications of graphene films include moisture barrier films, transparent conductive films, electromagnetic shielding films, and optical communications; such applications call different requirements for the performance of transferred graphene, which, in turn, determine the suitable transfer techniques. Besides the reliable transfer process, automatic machines should be well developed for the future batch transfer of graphene films, ensuring the repeatability and scalability. This mini-review provides a summary of recent advances in the transfer of graphene films and offers a perspective for future directions of transfer techniques that are compatible for industrial batch transfer.
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Affiliation(s)
- Yaqi Zhu
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, 266000, China.
- School of Materials Science and Engineering, Peking University, Beijing 100871, P. R. China.
- Beijing Graphene Institute, Beijing 100095, P. R. China.
| | - Zhuofeng Shi
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, 266000, China.
- School of Materials Science and Engineering, Peking University, Beijing 100871, P. R. China.
- Beijing Graphene Institute, Beijing 100095, P. R. China.
| | - Yixuan Zhao
- Beijing Graphene Institute, Beijing 100095, P. R. China.
- Center for Nanochemistry, Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Saiyu Bu
- School of Materials Science and Engineering, Peking University, Beijing 100871, P. R. China.
| | - Zhaoning Hu
- School of Materials Science and Engineering, Peking University, Beijing 100871, P. R. China.
- Beijing Graphene Institute, Beijing 100095, P. R. China.
| | - Junhao Liao
- Beijing Graphene Institute, Beijing 100095, P. R. China.
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, P. R. China
- National Center for Nanoscience and Technology, Beijing 100190, China
| | - Qi Lu
- Beijing Graphene Institute, Beijing 100095, P. R. China.
- State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, Beijing 102249, P. R. China
| | - Chaofan Zhou
- School of Materials Science and Engineering, Peking University, Beijing 100871, P. R. China.
- Beijing Graphene Institute, Beijing 100095, P. R. China.
| | - Bingbing Guo
- Beijing Graphene Institute, Beijing 100095, P. R. China.
| | - Mingpeng Shang
- Beijing Graphene Institute, Beijing 100095, P. R. China.
- Center for Nanochemistry, Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, P. R. China
| | - Fangfang Li
- Beijing Graphene Institute, Beijing 100095, P. R. China.
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, P. R. China
| | - Zhiying Xu
- School of Materials Science and Engineering, Peking University, Beijing 100871, P. R. China.
- Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, P. R. China
| | - Jialin Zhang
- School of Materials Science and Engineering, Peking University, Beijing 100871, P. R. China.
- Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, P. R. China
| | - Qin Xie
- Beijing Graphene Institute, Beijing 100095, P. R. China.
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, P. R. China
| | - Chunhu Li
- Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, P. R. China
| | - Pengzhan Sun
- Institute of Applied Physics and Materials, Engineering, University of Macau, Avenida da Universidade, Taipa, Macau SAR 999078, P.R. China
| | - Boyang Mao
- Department of Engineering, University of Cambridge, Cambridge, CB3 0FA, U.K
| | - Xiaodong Zhang
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, 266000, China.
| | - Zhongfan Liu
- Beijing Graphene Institute, Beijing 100095, P. R. China.
- Center for Nanochemistry, Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, P. R. China
| | - Li Lin
- School of Materials Science and Engineering, Peking University, Beijing 100871, P. R. China.
- Beijing Graphene Institute, Beijing 100095, P. R. China.
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, P. R. China
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16
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Kim J, Park J, Choi H, Kim T, Cha S, Lee Y, Watanabe K, Taniguchi T, Kim J, Jo MH, Choi H. Correlation-driven nonequilibrium exciton site transition in a WSe 2/WS 2 moiré supercell. Nat Commun 2024; 15:3312. [PMID: 38632336 PMCID: PMC11024152 DOI: 10.1038/s41467-024-47768-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 04/10/2024] [Indexed: 04/19/2024] Open
Abstract
Moiré superlattices of transition metal dichalcogenides offer a unique platform to explore correlated exciton physics with optical spectroscopy. Whereas the spatially modulated potentials evoke that the exciton resonances are distinct depending on a site in a moiré supercell, there have been no clear demonstration how the moiré excitons trapped in different sites dynamically interact with the doped carriers; so far the exciton-electron dynamic interactions were presumed to be site-dependent. Thus, the transient emergence of nonequilibrium correlations are open questions, but existing studies are limited to steady-state optical measurements. Here we report experimental fingerprints of site-dependent exciton correlations under continuous-wave as well as ultrashort optical excitations. In near-zero angle-aligned WSe2/WS2 heterobilayers, we observe intriguing polarization switching and strongly enhanced Pauli blocking near the Mott insulating state, dictating the dominant correlation-driven effects. When the twist angle is near 60°, no such correlations are observed, suggesting the strong dependence of atomic registry in moiré supercell configuration. Our studies open the door to largely unexplored nonequilibrium correlations of excitons in moiré superlattices.
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Affiliation(s)
- Jinjae Kim
- Department of Physics, Seoul National University, Seoul, 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Jiwon Park
- Department of Physics, Seoul National University, Seoul, 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Hyojin Choi
- Department of Physics, Seoul National University, Seoul, 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Taeho Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang, 37673, Korea
- Center for van der Waals Quantum Solids, Institute for Basic Science (IBS), Pohang, 37673, Korea
| | - Soonyoung Cha
- Department of Physics and Astronomy, University of California, Riverside, CA, 92521, USA
| | - Yewon Lee
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang, 37673, Korea
- Center for van der Waals Quantum Solids, Institute for Basic Science (IBS), Pohang, 37673, Korea
| | - Kenji Watanabe
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Takashi Taniguchi
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Jonghwan Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang, 37673, Korea
- Center for van der Waals Quantum Solids, Institute for Basic Science (IBS), Pohang, 37673, Korea
| | - Moon-Ho Jo
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang, 37673, Korea
- Center for van der Waals Quantum Solids, Institute for Basic Science (IBS), Pohang, 37673, Korea
| | - Hyunyong Choi
- Department of Physics, Seoul National University, Seoul, 08826, Korea.
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea.
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17
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Knorr W, Brem S, Meneghini G, Malic E. Polaron-induced changes in moiré exciton propagation in twisted van der Waals heterostructures. NANOSCALE 2024. [PMID: 38623653 DOI: 10.1039/d4nr00136b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Twisted transition metal dichalcogenides (TMDs) present an intriguing platform for exploring excitons and their transport properties. By introducing a twist angle, a moiré superlattice forms, providing a spatially dependent exciton energy landscape. Based on a microscopic many-particle theory, we investigate in this work polaron-induced changes in exciton transport properties in the exemplary MoSe2/WSe2 heterostructure. We demonstrate that polaron formation and the associated enhancement of the moiré exciton mass lead to a significant band flattening. As a result, the moiré inter-cell tunneling and the propagation velocity undergo noticeable temperature and twist-angle dependent changes. We predict a reduction of the hopping strength ranging from 80% at a twist angle of 1° to 30% at 3° at room temperature. The provided microscopic insights into the spatio-temporal exciton dynamics in presence of a moiré potential further expand the possibilities to tune charge and energy transport in 2D materials.
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Affiliation(s)
- Willy Knorr
- Department of Physics, Philipps University, 35037 Marburg, Germany.
| | - Samuel Brem
- Department of Physics, Philipps University, 35037 Marburg, Germany.
| | | | - Ermin Malic
- Department of Physics, Philipps University, 35037 Marburg, Germany.
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18
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Kim H, Kim C, Jung Y, Kim N, Son J, Lee GH. In-plane anisotropic two-dimensional materials for twistronics. NANOTECHNOLOGY 2024; 35:262501. [PMID: 38387091 DOI: 10.1088/1361-6528/ad2c53] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 02/22/2024] [Indexed: 02/24/2024]
Abstract
In-plane anisotropic two-dimensional (2D) materials exhibit in-plane orientation-dependent properties. The anisotropic unit cell causes these materials to show lower symmetry but more diverse physical properties than in-plane isotropic 2D materials. In addition, the artificial stacking of in-plane anisotropic 2D materials can generate new phenomena that cannot be achieved in in-plane isotropic 2D materials. In this perspective we provide an overview of representative in-plane anisotropic 2D materials and their properties, such as black phosphorus, group IV monochalcogenides, group VI transition metal dichalcogenides with 1T' and Tdphases, and rhenium dichalcogenides. In addition, we discuss recent theoretical and experimental investigations of twistronics using in-plane anisotropic 2D materials. Both in-plane anisotropic 2D materials and their twistronics hold considerable potential for advancing the field of 2D materials, particularly in the context of orientation-dependent optoelectronic devices.
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Affiliation(s)
- Hangyel Kim
- Department of Material Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Changheon Kim
- Department of Material Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
- Functional Composite Materials Research Center, Korea Institute of Science and Technology (KIST), Jeonbuk 55324, Republic of Korea
| | - Yeonwoong Jung
- NanoScience Technology Center, University of Central Florida, Orlando, FL 32826, United States of America
- Department of Materials Science and Engineering, University of Central Florida, Orlando, FL 32816, United States of America
- Department of Electrical and Computer Engineering, University of Central Florida, Orlando, FL 32816, United States of America
| | - Namwon Kim
- Research Institute for Advanced Materials (RIAM), Seoul National University, Seoul 08826, Republic of Korea
- Ingram School of Engineering, Texas State University, San Marcos, TX 78666, United States of America
- Materials Science, Engineering, and Commercialization, Texas State University, San Marcos, TX 78666, United States of America
| | - Jangyup Son
- Functional Composite Materials Research Center, Korea Institute of Science and Technology (KIST), Jeonbuk 55324, Republic of Korea
- Department of JBNU-KIST Industry-Academia Convergence Research, Jeonbuk National University, Jeonbuk 54895, Republic of Korea
- Division of Nano and Information Technology, KIST School University of Science and Technology(UST), Jeonbuk 55324, Republic of Korea
| | - Gwan-Hyoung Lee
- Department of Material Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute for Advanced Materials (RIAM), Seoul National University, Seoul 08826, Republic of Korea
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19
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Arsenault EA, Li Y, Yang B, Wang X, Park H, Mosconi E, Ronca E, Taniguchi T, Watanabe K, Gamelin D, Millis A, Dean CR, de Angelis F, Xu X, Zhu XY. Two-Dimensional Moiré Polaronic Electron Crystals. PHYSICAL REVIEW LETTERS 2024; 132:126501. [PMID: 38579228 DOI: 10.1103/physrevlett.132.126501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 02/03/2024] [Accepted: 02/23/2024] [Indexed: 04/07/2024]
Abstract
Two-dimensional moiré materials have emerged as the most versatile platform for realizing quantum phases of electrons. Here, we explore the stability origins of correlated states in WSe_{2}/WS_{2} moiré superlattices. We find that ultrafast electronic excitation leads to partial melting of the Mott states on timescales 5 times longer than predictions from the charge hopping integrals and that the melting rates are thermally activated, with activation energies of 18±3 and 13±2 meV for the one- and two-hole Mott states, respectively, suggesting significant electron-phonon coupling. A density functional theory calculation of the one-hole Mott state confirms polaron formation and yields a hole-polaron binding energy of 16 meV. These findings reveal a close interplay of electron-electron and electron-phonon interactions in stabilizing the polaronic Mott insulators at transition metal dichalcogenide moiré interfaces.
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Affiliation(s)
- Eric A Arsenault
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Yiliu Li
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Birui Yang
- Department of Physics, Columbia University, New York, New York 10027, USA
| | - Xi Wang
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Heonjoon Park
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
| | - Edoardo Mosconi
- Istituto CNR di Scienze e Tecnologie Chimiche (CNR-SCITEC), CLHYO, 06123 Perugia, Italy
| | - Enrico Ronca
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123, Perugia, Italy
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | - Daniel Gamelin
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Andrew Millis
- Department of Physics, Columbia University, New York, New York 10027, USA
| | - Cory R Dean
- Department of Physics, Columbia University, New York, New York 10027, USA
| | - Filippo de Angelis
- Istituto CNR di Scienze e Tecnologie Chimiche (CNR-SCITEC), CLHYO, 06123 Perugia, Italy
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123, Perugia, Italy
- Department of Mechanical Engineering, Prince Mohammad Bin Fahd University, Al Khobar, 31952, Saudi Arabia
- SKKU Institute of Energy Science and Technology, Sungkyunkwan University, Suwon, Korea 440-746
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA
| | - X Y Zhu
- Department of Chemistry, Columbia University, New York, New York 10027, USA
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20
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Cai CS, Lai WY, Liu PH, Chou TC, Liu RY, Lin CM, Gwo S, Hsu WT. Ultralow Auger-Assisted Interlayer Exciton Annihilation in WS 2/WSe 2 Moiré Heterobilayers. NANO LETTERS 2024; 24:2773-2781. [PMID: 38285707 PMCID: PMC10921466 DOI: 10.1021/acs.nanolett.3c04688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 01/31/2024]
Abstract
Transition metal dichalcogenide (TMD) heterobilayers have emerged as a promising platform for exploring solid-state quantum simulators and many-body quantum phenomena. Their type II band alignment, combined with the moiré superlattice, inevitably leads to nontrivial exciton interactions and dynamics. Here, we unveil the distinct Auger annihilation processes for delocalized interlayer excitons in WS2/WSe2 moiré heterobilayers. By fitting the characteristic efficiency droop and bimolecular recombination rate, we quantitatively determine an ultralow Auger coefficient of 1.3 × 10-5 cm2 s-1, which is >100-fold smaller than that of excitons in TMD monolayers. In addition, we reveal selective exciton upconversion into the WSe2 layer, which highlights the significance of intralayer electron Coulomb interactions in dictating the microscopic scattering pathways. The distinct Auger processes arising from spatial electron-hole separation have important implications for TMD heterobilayers while endowing interlayer excitons and their strongly correlated states with unique layer degrees of freedom.
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Affiliation(s)
- Cheng-Syuan Cai
- Department
of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
- National
Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Wei-Yan Lai
- Department
of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Po-Hsuan Liu
- Department
of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Tzu-Chieh Chou
- Department
of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
- National
Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Ro-Ya Liu
- National
Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Chih-Ming Lin
- Department
of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Shangjr Gwo
- Department
of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Wei-Ting Hsu
- Department
of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
- National
Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
- Research
Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
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21
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Sun X, Suriyage M, Khan AR, Gao M, Zhao J, Liu B, Hasan MM, Rahman S, Chen RS, Lam PK, Lu Y. Twisted van der Waals Quantum Materials: Fundamentals, Tunability, and Applications. Chem Rev 2024; 124:1992-2079. [PMID: 38335114 DOI: 10.1021/acs.chemrev.3c00627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2024]
Abstract
Twisted van der Waals (vdW) quantum materials have emerged as a rapidly developing field of two-dimensional (2D) semiconductors. These materials establish a new central research area and provide a promising platform for studying quantum phenomena and investigating the engineering of novel optoelectronic properties such as single photon emission, nonlinear optical response, magnon physics, and topological superconductivity. These captivating electronic and optical properties result from, and can be tailored by, the interlayer coupling using moiré patterns formed by vertically stacking atomic layers with controlled angle misorientation or lattice mismatch. Their outstanding properties and the high degree of tunability position them as compelling building blocks for both compact quantum-enabled devices and classical optoelectronics. This paper offers a comprehensive review of recent advancements in the understanding and manipulation of twisted van der Waals structures and presents a survey of the state-of-the-art research on moiré superlattices, encompassing interdisciplinary interests. It delves into fundamental theories, synthesis and fabrication, and visualization techniques, and the wide range of novel physical phenomena exhibited by these structures, with a focus on their potential for practical device integration in applications ranging from quantum information to biosensors, and including classical optoelectronics such as modulators, light emitting diodes, lasers, and photodetectors. It highlights the unique ability of moiré superlattices to connect multiple disciplines, covering chemistry, electronics, optics, photonics, magnetism, topological and quantum physics. This comprehensive review provides a valuable resource for researchers interested in moiré superlattices, shedding light on their fundamental characteristics and their potential for transformative applications in various fields.
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Affiliation(s)
- Xueqian Sun
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Manuka Suriyage
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Ahmed Raza Khan
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
- Department of Industrial and Manufacturing Engineering, University of Engineering and Technology (Rachna College Campus), Gujranwala, Lahore 54700, Pakistan
| | - Mingyuan Gao
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
- College of Engineering and Technology, Southwest University, Chongqing 400716, China
| | - Jie Zhao
- Department of Quantum Science & Technology, Research School of Physics, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
- Australian Research Council Centre of Excellence for Quantum Computation and Communication Technology, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Boqing Liu
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Md Mehedi Hasan
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Sharidya Rahman
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia
- ARC Centre of Excellence in Exciton Science, Monash University, Clayton, Victoria 3800, Australia
| | - Ruo-Si Chen
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Ping Koy Lam
- Department of Quantum Science & Technology, Research School of Physics, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
- Australian Research Council Centre of Excellence for Quantum Computation and Communication Technology, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Yuerui Lu
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
- Australian Research Council Centre of Excellence for Quantum Computation and Communication Technology, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
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22
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Liu H, Zhang Z, Zhang C, Li X, Zhang C, Xu F, Wu Y, Wu Z, Kang J. Simultaneously Regulated Highly Polarized and Long-Lived Valley Excitons in WSe 2/GaN Heterostructures. NANO LETTERS 2024; 24:1851-1858. [PMID: 38315876 DOI: 10.1021/acs.nanolett.3c03494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Interlayer excitons, with prolonged lifetimes and tunability, hold potential for advanced optoelectronics. Previous research on the interlayer excitons has been dominated by two-dimensional heterostructures. Here, we construct WSe2/GaN composite heterostructures, in which the doping concentration of GaN and the twist angle of bilayer WSe2 are employed as two ingredients for the manipulation of exciton behaviors and polarizations. The exciton energies in monolayer WSe2/GaN can be regulated continuously by the doping levels of the GaN substrate, and a remarkable increase in the valley polarizations is achieved. Especially in a heterostructure with 4°-twisted bilayer WSe2, a maximum polarization of 38.9% with a long lifetime is achieved for the interlayer exciton. Theoretical calculations reveal that the large polarization and long lifetime are attributed to the high exciton binding energy and large spin flipping energy during depolarization in bilayer WSe2/GaN. This work introduces a distinctive member of the interlayer exciton with a high degree of polarization and a long lifetime.
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Affiliation(s)
- Haiyang Liu
- Department of Physics, Engineering Research Centre for Micro-Nano Optoelectronic Materials and Devices at Education Ministry, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen 361005, P. R. China
- School of Physical Science and Technology, Wuhan University, Wuhan 430072, P. R. China
| | - Zongnan Zhang
- Department of Physics, Engineering Research Centre for Micro-Nano Optoelectronic Materials and Devices at Education Ministry, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen 361005, P. R. China
| | - Chenhao Zhang
- Department of Physics, Engineering Research Centre for Micro-Nano Optoelectronic Materials and Devices at Education Ministry, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen 361005, P. R. China
| | - Xu Li
- Department of Physics, Engineering Research Centre for Micro-Nano Optoelectronic Materials and Devices at Education Ministry, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen 361005, P. R. China
| | - Chunmiao Zhang
- Department of Physics, Engineering Research Centre for Micro-Nano Optoelectronic Materials and Devices at Education Ministry, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen 361005, P. R. China
| | - Feiya Xu
- Department of Physics, Engineering Research Centre for Micro-Nano Optoelectronic Materials and Devices at Education Ministry, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen 361005, P. R. China
| | - Yaping Wu
- Department of Physics, Engineering Research Centre for Micro-Nano Optoelectronic Materials and Devices at Education Ministry, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen 361005, P. R. China
| | - Zhiming Wu
- Department of Physics, Engineering Research Centre for Micro-Nano Optoelectronic Materials and Devices at Education Ministry, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen 361005, P. R. China
| | - Junyong Kang
- Department of Physics, Engineering Research Centre for Micro-Nano Optoelectronic Materials and Devices at Education Ministry, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen 361005, P. R. China
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23
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Johnson AC, Georgaras JD, Shen X, Yao H, Saunders AP, Zeng HJ, Kim H, Sood A, Heinz TF, Lindenberg AM, Luo D, da Jornada FH, Liu F. Hidden phonon highways promote photoinduced interlayer energy transfer in twisted transition metal dichalcogenide heterostructures. SCIENCE ADVANCES 2024; 10:eadj8819. [PMID: 38266081 PMCID: PMC10807799 DOI: 10.1126/sciadv.adj8819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 12/22/2023] [Indexed: 01/26/2024]
Abstract
Vertically stacked van der Waals (vdW) heterostructures exhibit unique electronic, optical, and thermal properties that can be manipulated by twist-angle engineering. However, the weak phononic coupling at a bilayer interface imposes a fundamental thermal bottleneck for future two-dimensional devices. Using ultrafast electron diffraction, we directly investigated photoinduced nonequilibrium phonon dynamics in MoS2/WS2 at 4° twist angle and WSe2/MoSe2 heterobilayers with twist angles of 7°, 16°, and 25°. We identified an interlayer heat transfer channel with a characteristic timescale of ~20 picoseconds, about one order of magnitude faster than molecular dynamics simulations assuming initial intralayer thermalization. Atomistic calculations involving phonon-phonon scattering suggest that this process originates from the nonthermal phonon population following the initial interlayer charge transfer and scattering. Our findings present an avenue for thermal management in vdW heterostructures by tailoring nonequilibrium phonon populations.
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Affiliation(s)
- Amalya C. Johnson
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Johnathan D. Georgaras
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Xiaozhe Shen
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Helen Yao
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | | | - Helen J. Zeng
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Hyungjin Kim
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Aditya Sood
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Tony F. Heinz
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
- Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - Aaron M. Lindenberg
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Duan Luo
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Felipe H. da Jornada
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Fang Liu
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
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24
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Liu H, Wang J, Chen S, Sun Z, Xu H, Han Y, Wang C, Liu H, Huang L, Luo J, Liu D. Direct Visualization of Dark Interlayer Exciton Transport in Moiré Superlattices. NANO LETTERS 2024; 24:339-346. [PMID: 38147355 DOI: 10.1021/acs.nanolett.3c04105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
Moiré superlattices have emerged as an unprecedented manipulation tool for engineering correlated quantum phenomena in van der Waals heterostructures. With moiré potentials as a naturally configurable solid-state that sustains high exciton density, interlayer excitons in transition metal dichalcogenide heterostructures are expected to achieve high-temperature exciton condensation. However, the exciton degeneracy state is usually optically inactive due to the finite momentum of interlayer excitons. Experimental observation of dark interlayer excitons in moiré potentials remains challenging. Here we directly visualize the dark interlayer exciton transport in WS2/h-BN/WSe2 heterostructures using femtosecond transient absorption microscopy. We observe a transition from classical free exciton gas to quantum degeneracy by imaging temperature-dependent exciton transport. Below a critical degeneracy temperature, exciton diffusion rates exhibit an accelerating downward trend, which can be explained well by a nonlinear quantum diffusion model. These results open the door to quantum information processing and high-precision metrology in moiré superlattices.
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Affiliation(s)
- Huan Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Jiangcai Wang
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Shihong Chen
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Zejun Sun
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Haowen Xu
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
| | - Yishu Han
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Chong Wang
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Huixian Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Li Huang
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Jianbin Luo
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Dameng Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
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25
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Sun C, Zhou H, Sheng T, Li S, Zhu H. Ultrafast Interlayer Charge Transfer Outcompeting Intralayer Valley Relaxation in Few-Layer 2D Heterostructures. ACS NANO 2024; 18:931-938. [PMID: 38154000 DOI: 10.1021/acsnano.3c09681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2023]
Abstract
While 2D transition metal dichalcogenides (TMDs) feature interesting layer-tunable multivalley band structures, their preeminent role in determining the photoexcitation charge transfer dynamics in 2D heterostructures (HSs) is yet to be unraveled, as previous charge transfer studies on TMD HSs have been mostly focused on monolayers with a direct bandgap at the K valley. By ultrafast transient absorption spectroscopy and deliberately designed few-layer WSe2/WS2 HSs, we have observed an ultrafast interlayer electron transfer from photoexcited few-layer WSe2 to WS2, prior to intralayer relaxation to lower lying dark valleys. More interestingly, we have identified an unconventional ∼0.5 ps electron back-transfer process after the initial interlayer electron transfer in HSs with WSe2 layers ≥ 3, regenerating indirect intralayer excitons. The result reveals an ielectron and valley relaxation pathway mediated by interlayer charge transfer in 2D HSs, faster than intralayer relaxation. It also sheds light on the origin of generally observed robust ultrafast interlayer charge transfer in TMD HSs and provides guidance toward optoelectronic and valleytronic devices using few-layer TMDs.
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Affiliation(s)
- Cheng Sun
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China, 310027
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, Zhejiang, China, 311215
| | - Hongzhi Zhou
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China, 310027
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, Zhejiang, China, 311215
| | - Tianyu Sheng
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China, 310027
| | - Shuangshuang Li
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China, 310027
| | - Haiming Zhu
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China, 310027
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, Zhejiang, China, 311215
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Wietek E, Florian M, Göser J, Taniguchi T, Watanabe K, Högele A, Glazov MM, Steinhoff A, Chernikov A. Nonlinear and Negative Effective Diffusivity of Interlayer Excitons in Moiré-Free Heterobilayers. PHYSICAL REVIEW LETTERS 2024; 132:016202. [PMID: 38242648 DOI: 10.1103/physrevlett.132.016202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 11/10/2023] [Indexed: 01/21/2024]
Abstract
Interlayer exciton diffusion is studied in atomically reconstructed MoSe_{2}/WSe_{2} heterobilayers with suppressed disorder. Local atomic registry is confirmed by characteristic optical absorption, circularly polarized photoluminescence, and g-factor measurements. Using transient microscopy we observe propagation properties of interlayer excitons that are independent from trapping at moiré- or disorder-induced local potentials. Confirmed by characteristic temperature dependence for free particles, linear diffusion coefficients of interlayer excitons at liquid helium temperature and low excitation densities are almost 1000 times higher than in previous observations. We further show that exciton-exciton repulsion and annihilation contribute nearly equally to nonlinear propagation by disentangling the two processes in the experiment and simulations. Finally, we demonstrate effective shrinking of the light emission area over time across several hundreds of picoseconds at the transition from exciton- to the plasma-dominated regimes. Supported by microscopic calculations for band gap renormalization to identify the Mott threshold, this indicates transient crossing between rapidly expanding, short-lived electron-hole plasma and slower, long-lived exciton populations.
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Affiliation(s)
- Edith Wietek
- Institute of Applied Physics and Würzburg-Dresden Cluster of Excellence ct.qmat, Technische Universität Dresden, 01062 Dresden, Germany
| | - Matthias Florian
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Jonas Göser
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, 80539 München, Germany
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Alexander Högele
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, 80539 München, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
| | | | - Alexander Steinhoff
- Institut für Theoretische Physik, Universität Bremen, 28334 Bremen, Germany
- Bremen Center for Computational Materials Science, Universität Bremen, 28334 Bremen, Germany
| | - Alexey Chernikov
- Institute of Applied Physics and Würzburg-Dresden Cluster of Excellence ct.qmat, Technische Universität Dresden, 01062 Dresden, Germany
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Qian W, Qi P, Dai Y, Shi B, Tao G, Liu H, Zhang X, Xiang D, Fang Z, Liu W. Strongly Localized Moiré Exciton in Twisted Homobilayers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2305200. [PMID: 37649150 DOI: 10.1002/smll.202305200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/14/2023] [Indexed: 09/01/2023]
Abstract
Artificially molding exciton flux is the cornerstone for developing promising excitonic devices. In the emerging hetero/homobilayers, the spatial separated charges prolong exciton lifetimes and create out-plane dipoles, facilitating electrically control exciton flux on a large scale, and the nanoscale periodic moiré potentials arising from twist-angle or/and lattice mismatch can substantially alter exciton dynamics, which are mainly proved in the heterostructures. However, the spatially indirect excitons dynamics in homobilayers without lattice mismatch remain elusive. Here the nonequilibrium dynamics of indirect exciton in homobilayers are systematically investigated. The homobilayers with slightly twist-angle can induce a deep moiré potential (>50 meV) in the energy landscape of indirect excitons, resulting in a strongly localized moiré excitons insulating the transport dynamics from phonons and disorder. These findings provide insights into the exciton dynamics and many-body physics in moiré superlattices modulated energy landscape, with implications for designing excitonic devices operating at room temperature.
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Affiliation(s)
- Wenqi Qian
- Institute of Modern Optics, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, Tianjin, 300350, China
| | - Pengfei Qi
- Institute of Modern Optics, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, Tianjin, 300350, China
| | - Yuchen Dai
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing, 100871, China
| | - Beibei Shi
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing, 100871, China
| | - Guangyi Tao
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing, 100871, China
| | - Haiyi Liu
- Institute of Modern Optics, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, Tianjin, 300350, China
| | - Xubin Zhang
- Institute of Modern Optics, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, Tianjin, 300350, China
| | - Dong Xiang
- Institute of Modern Optics, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, Tianjin, 300350, China
| | - Zheyu Fang
- School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing, 100871, China
| | - Weiwei Liu
- Institute of Modern Optics, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, Tianjin, 300350, China
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28
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Tsai MY, Tsai TH, Gandhi AC, Lu HL, Li JX, Chen PL, Chen KW, Chen SZ, Chen CH, Liu CH, Lin YF, Chiu PW. Ultrafast and Broad-Band Graphene Heterojunction Photodetectors with High Gain. ACS NANO 2023; 17:25037-25044. [PMID: 38096421 DOI: 10.1021/acsnano.3c07665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
Graphene possesses an exotic band structure that spans a wide range of important technological wavelength regimes for photodetection, all within a single material. Conventional methods aimed at enhancing detection efficiency often suffer from an extended response time when the light is switched off. The task of achieving ultrafast broad-band photodetection with a high gain remains challenging. Here, we propose a devised architecture that combines graphene with a photosensitizer composed of an alternating strip superstructure of WS2-WSe2. Upon illumination, n+-WS2 and p+-WSe2 strips create alternating electron- and hole-conduction channels in graphene, effectively overcoming the tradeoff between the responsivity and switch time. This configuration allows for achieving a responsivity of 1.7 × 107 mA/W, with an extrinsic response time of 3-4 μs. The inclusion of the superstructure booster enables photodetection across a wide range from the near-ultraviolet to mid-infrared regime and offers a distinctive photogating route for high responsivity and fast temporal response in the pursuit of broad-band detection.
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Affiliation(s)
- Meng-Yu Tsai
- Institute of Electronics Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Physics, National Chung Hsing University, Taichung 40227, Taiwan
| | - Tsung-Han Tsai
- Institute of Electronics Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | | | - Hsueh-Lung Lu
- Institute of Electronics Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Jia-Xin Li
- Institute of Electronics Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Po-Liang Chen
- Institute of Electronics Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Kai-Wen Chen
- Department of Materials Science & Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Sun-Zen Chen
- Center for Nanotechnology, Materials Science and Microsystem, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Chia-Hao Chen
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Chang-Hua Liu
- Institute of Electronics Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Yen-Fu Lin
- Department of Physics, National Chung Hsing University, Taichung 40227, Taiwan
| | - Po-Wen Chiu
- Institute of Electronics Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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29
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Lee H, Kim YB, Ryu JW, Kim S, Bae J, Koo Y, Jang D, Park KD. Recent progress of exciton transport in two-dimensional semiconductors. NANO CONVERGENCE 2023; 10:57. [PMID: 38102309 PMCID: PMC10724105 DOI: 10.1186/s40580-023-00404-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 11/20/2023] [Indexed: 12/17/2023]
Abstract
Spatial manipulation of excitonic quasiparticles, such as neutral excitons, charged excitons, and interlayer excitons, in two-dimensional semiconductors offers unique capabilities for a broad range of optoelectronic applications, encompassing photovoltaics, exciton-integrated circuits, and quantum light-emitting systems. Nonetheless, their practical implementation is significantly restricted by the absence of electrical controllability for neutral excitons, short lifetime of charged excitons, and low exciton funneling efficiency at room temperature, which remain a challenge in exciton transport. In this comprehensive review, we present the latest advancements in controlling exciton currents by harnessing the advanced techniques and the unique properties of various excitonic quasiparticles. We primarily focus on four distinct control parameters inducing the exciton current: electric fields, strain gradients, surface plasmon polaritons, and photonic cavities. For each approach, the underlying principles are introduced in conjunction with its progression through recent studies, gradually expanding their accessibility, efficiency, and functionality. Finally, we outline the prevailing challenges to fully harness the potential of excitonic quasiparticles and implement practical exciton-based optoelectronic devices.
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Affiliation(s)
- Hyeongwoo Lee
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Yong Bin Kim
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Jae Won Ryu
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Sujeong Kim
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Jinhyuk Bae
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Yeonjeong Koo
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Donghoon Jang
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Kyoung-Duck Park
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
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30
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Wang A, Yao W, Yang Z, Zheng D, Li S, Shi Y, Li D, Wang F. Probing the interlayer excitation dynamics in WS 2/WSe 2 heterostructures with broadly tunable pump and probe energies. NANOSCALE 2023. [PMID: 38050459 DOI: 10.1039/d3nr04878k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2023]
Abstract
van der Waals heterostructures based on transition metal dichalcogenides (TMDs) provide a fascinating platform for exploring new physical phenomena and novel optoelectronic functionalities. Revealing the energy-dependence of photocarrier population dynamics in heterostructures is key for developing optoelectronic or valleytronic devices. Here, the broadband transient dynamics of interlayer excitation of a nearly-aligned WS2/WSe2 heterostructure is investigated by using energy-dependent pump-probe spectroscopy at cryogenic temperatures. Interestingly, WS2/WSe2 interlayer excitation, herein comprising a mixture of intra- and inter-layer excitons, exhibits largely constant lifetimes of a few hundred picoseconds across a broad energy range, in stark contrast to the salient energy-dependent dynamics of intralayer excitons in monolayer WSe2. While the PL emission of the WS2/WSe2 heterostructure is found to be strongly affected by electrostatic doping, the lifetimes of interlayer excitation show negligible changes. Our work elaborates the signatures of ultrafast dynamics introduced by intra- and interlayer co-existing excitonic species and enriches the understanding of interlayer couplings in van der Waals heterostructures.
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Affiliation(s)
- Anran Wang
- School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
| | - Wendian Yao
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zidi Yang
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Dingqi Zheng
- School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
| | - Songlin Li
- School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
| | - Yi Shi
- School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
| | - Dehui Li
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Fengqiu Wang
- School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
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31
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Fang H, Lin Q, Zhang Y, Thompson J, Xiao S, Sun Z, Malic E, Dash SP, Wieczorek W. Localization and interaction of interlayer excitons in MoSe 2/WSe 2 heterobilayers. Nat Commun 2023; 14:6910. [PMID: 37903787 PMCID: PMC10616232 DOI: 10.1038/s41467-023-42710-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 10/19/2023] [Indexed: 11/01/2023] Open
Abstract
Transition metal dichalcogenide (TMD) heterobilayers provide a versatile platform to explore unique excitonic physics via the properties of the constituent TMDs and external stimuli. Interlayer excitons (IXs) can form in TMD heterobilayers as delocalized or localized states. However, the localization of IX in different types of potential traps, the emergence of biexcitons in the high-excitation regime, and the impact of potential traps on biexciton formation have remained elusive. In our work, we observe two types of potential traps in a MoSe2/WSe2 heterobilayer, which result in significantly different emission behavior of IXs at different temperatures. We identify the origin of these traps as localized defect states and the moiré potential of the TMD heterobilayer. Furthermore, with strong excitation intensity, a superlinear emission behavior indicates the emergence of interlayer biexcitons, whose formation peaks at a specific temperature. Our work elucidates the different excitation and temperature regimes required for the formation of both localized and delocalized IX and biexcitons and, thus, contributes to a better understanding and application of the rich exciton physics in TMD heterostructures.
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Affiliation(s)
- Hanlin Fang
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, 41296, Gothenburg, Sweden.
| | - Qiaoling Lin
- Department of Electrical and Photonics Engineering, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
| | - Yi Zhang
- Department of Electronics and Nanoengineering and QTF Centre of Excellence, Aalto University, Espoo, 02150, Finland
| | - Joshua Thompson
- Department of Physics, Philipps-Universität Marburg, 35037, Marburg, Germany
| | - Sanshui Xiao
- Department of Electrical and Photonics Engineering, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
| | - Zhipei Sun
- Department of Electronics and Nanoengineering and QTF Centre of Excellence, Aalto University, Espoo, 02150, Finland
| | - Ermin Malic
- Department of Physics, Philipps-Universität Marburg, 35037, Marburg, Germany
| | - Saroj P Dash
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Witlef Wieczorek
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, 41296, Gothenburg, Sweden.
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Liu J, Yang X, Fang H, Yan W, Ouyang W, Liu Z. In Situ Twistronics: A New Platform Based on Superlubricity. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023:e2305072. [PMID: 37867201 DOI: 10.1002/adma.202305072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 07/19/2023] [Indexed: 10/24/2023]
Abstract
Twistronics, an emerging field focused on exploring the unique electrical properties induced by twist interface in graphene multilayers, has garnered significant attention in recent years. The general manipulation of twist angle depends on the assembly of van der Waals (vdW) layered materials, which has led to the discovery of unconventional superconductivity, ferroelectricity, and nonlinear optics, thereby expanding the realm of twistronics. Recently, in situ tuning of interlayer conductivity in vdW layered materials has been achieved based on scanning probe microscope. In this Perspective, the advancements in in situ twistronics are focused on by reviewing the state-of-the-art in situ manipulating technology, discussing the underlying mechanism based on the concept of structural superlubricity, and exploiting the real-time twistronic tests under scanning electron microscope (SEM). It is shown that the real-time manipulation under SEM allows for visualizing and monitoring the interface status during in situ twistronic testing. By harnessing the unique tribological properties of vdW layered materials, this novel platform not only enhances the fabrication of twistronic devices but also facilitates the fundamental understanding of interface phenomena in vdW layered materials. Moreover, this platform holds great promise for the application of twistronic-mechanical systems, providing avenues for the integration of twistronics into various mechanical frameworks.
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Affiliation(s)
- Jianxin Liu
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei, 430072, China
| | - Xiaoqi Yang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei, 430072, China
| | - Hui Fang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei, 430072, China
| | - Weidong Yan
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei, 430072, China
| | - Wengen Ouyang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei, 430072, China
- State Key Laboratory of Water Resources Engineering and Management, Wuhan University, Wuhan, Hubei, 430072, P. R. China
| | - Ze Liu
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei, 430072, China
- State Key Laboratory of Water Resources Engineering and Management, Wuhan University, Wuhan, Hubei, 430072, P. R. China
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33
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Jiao C, Pei S, Wu S, Wang Z, Xia J. Tuning and exploiting interlayer coupling in two-dimensional van der Waals heterostructures. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2023; 86:114503. [PMID: 37774692 DOI: 10.1088/1361-6633/acfe89] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 09/29/2023] [Indexed: 10/01/2023]
Abstract
Two-dimensional (2D) layered materials can stack into new material systems, with van der Waals (vdW) interaction between the adjacent constituent layers. This stacking process of 2D atomic layers creates a new degree of freedom-interlayer interface between two adjacent layers-that can be independently studied and tuned from the intralayer degree of freedom. In such heterostructures (HSs), the physical properties are largely determined by the vdW interaction between the individual layers,i.e.interlayer coupling, which can be effectively tuned by a number of means. In this review, we summarize and discuss a number of such approaches, including stacking order, electric field, intercalation, and pressure, with both their experimental demonstrations and theoretical predictions. A comprehensive overview of the modulation on structural, optical, electrical, and magnetic properties by these four approaches are also presented. We conclude this review by discussing several prospective research directions in 2D HSs field, including fundamental physics study, property tuning techniques, and future applications.
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Affiliation(s)
- Chenyin Jiao
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, People's Republic of China
| | - Shenghai Pei
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, People's Republic of China
| | - Song Wu
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, People's Republic of China
| | - Zenghui Wang
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, People's Republic of China
| | - Juan Xia
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, People's Republic of China
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34
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Wu B, Zheng H, Li S, Wang CT, Ding J, He J, Liu Z, Wang JT, Liu Y. Enhanced Homogeneity of Moiré Superlattices in Double-Bilayer WSe 2 Homostructure. ACS APPLIED MATERIALS & INTERFACES 2023; 15:48475-48484. [PMID: 37796741 DOI: 10.1021/acsami.3c06949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
Moiré superlattices have emerged as a promising platform for investigating and designing optically generated excitonic properties. The electronic band structure of these systems can be qualitatively modulated by interactions between the top and bottom layers, leading to the emergence of new quantum phenomena. However, the inhomogeneities present in atomically thin bilayer moiré superlattices created by artificial stacking have hindered a deeper understanding of strongly correlated electron properties. In this work, we report the fabrication of homogeneous moiré superlattices with controllable twist angles using a 2L-WSe2/2L-WSe2 homostructure. By adding extra layers, we provide additional degrees of freedom to tune the optical properties of the moiré superlattices while mitigating the nonuniformity problem. The presence of an additional bottom layer acts as a buffer, reducing the inhomogeneity of the moiré superlattice, while the encapsulation effect of the additional top and bottom WSe2 monolayers further enhances the localized moiré excitons. Our observations of alternating circularly polarized photoluminescence confirm the existence of moiré excitons, and their characteristics were further confirmed by theoretical calculations. These findings provide a fundamental basis for studying moiré potential correlated quantum phenomena and pave the way for their application in quantum optical devices.
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Affiliation(s)
- Biao Wu
- School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan 410083, People's Republic of China
- State Key Laboratory of High-Performance Complex Manufacturing, Central South University, 932 South Lushan Road, Changsha, Hunan 410083, People's Republic of China
| | - Haihong Zheng
- School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan 410083, People's Republic of China
- State Key Laboratory of High-Performance Complex Manufacturing, Central South University, 932 South Lushan Road, Changsha, Hunan 410083, People's Republic of China
| | - Shaofei Li
- School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan 410083, People's Republic of China
| | - Chang-Tian Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Junnan Ding
- School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan 410083, People's Republic of China
| | - Jun He
- School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan 410083, People's Republic of China
| | - Zongwen Liu
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW 2006, Australia
- The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006 ,Australia
| | - Jian-Tao Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
| | - Yanping Liu
- School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan 410083, People's Republic of China
- State Key Laboratory of High-Performance Complex Manufacturing, Central South University, 932 South Lushan Road, Changsha, Hunan 410083, People's Republic of China
- Shenzhen Research Institute of Central South University, Shenzhen 518000, People's Republic of China
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35
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Aly MA, Enakerakpor EO, Koch M, Masenda H. Tuning Interlayer Exciton Emission with TMD Alloys in van der Waals Heterobilayers of Mo 0.5W 0.5Se 2 and Its Binary Counterparts. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2769. [PMID: 37887920 PMCID: PMC10609229 DOI: 10.3390/nano13202769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 10/12/2023] [Accepted: 10/14/2023] [Indexed: 10/28/2023]
Abstract
Semiconductor heterostructures have been the backbone of developments in electronic and optoelectronic devices. One class of structures of interest is the so-called type II band alignment, in which optically excited electrons and holes relax into different material layers. The unique properties observed in two-dimensional transition metal dichalcogenides and the possibility to engineer van der Waals heterostructures make them candidates for future high-tech devices. In these structures, electronic, optical, and magnetic properties can be tuned through the interlayer coupling, thereby opening avenues for developing new functional materials. We report the possibility of explicitly tuning the emission of interlayer exciton energies in the binary-ternary heterobilayer of Mo0.5W0.5Se2 with MoSe2 and WSe2. The respective interlayer energies of 1.516 eV and 1.490 eV were observed from low-temperature photoluminescence measurements for the MoSe2- and WSe2- based heterostructures, respectively. These interlayer emission energies are above those reported for MoSe2/WSe2 (≃1.30-1.45 eV). Consequently, binary-ternary heterostructure systems offer an extended energy range and tailored emission energies not accessible with the binary counterparts. Moreover, even though Mo0.5W0.5Se2 and MoSe2 have almost similar optical gaps, their band offsets are different, resulting in charge transfer between the monolayers following the optical excitation. Thus, confirming TMDs alloys can be used to tune the band-offsets, which adds another design parameter for application-specific optoelectronic devices.
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Affiliation(s)
- Mohammed Adel Aly
- Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg, 35032 Marburg, Germany
- Department of Physics, Faculty of Science, Ain Shams University, Cairo 11566, Egypt
| | | | - Martin Koch
- Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg, 35032 Marburg, Germany
| | - Hilary Masenda
- Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg, 35032 Marburg, Germany
- School of Physics, University of the Witwatersrand, Johannesburg 2050, South Africa
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36
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Baek JH, Kim HG, Lim SY, Hong SC, Chang Y, Ryu H, Jung Y, Jang H, Kim J, Zhang Y, Watanabe K, Taniguchi T, Huang PY, Cheong H, Kim M, Lee GH. Thermally induced atomic reconstruction into fully commensurate structures of transition metal dichalcogenide layers. NATURE MATERIALS 2023:10.1038/s41563-023-01690-2. [PMID: 37828101 DOI: 10.1038/s41563-023-01690-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 09/13/2023] [Indexed: 10/14/2023]
Abstract
Twist angle between two-dimensional layers is a critical parameter that determines their interfacial properties, such as moiré excitons and interfacial ferro-electricity. To achieve better control over these properties for fundamental studies and various applications, considerable efforts have been made to manipulate twist angle. However, due to mechanical limitations and the inevitable formation of incommensurate regions, there remains a challenge in attaining perfect alignment of crystalline orientation. Here we report a thermally induced atomic reconstruction of randomly stacked transition metal dichalcogenide multilayers into fully commensurate heterostructures with zero twist angle by encapsulation annealing, regardless of twist angles of as-stacked samples and lattice mismatches. We also demonstrate the selective formation of R- and H-type fully commensurate phases with a seamless lateral junction using chemical vapour-deposited transition metal dichalcogenides. The resulting fully commensurate phases exhibit strong photoluminescence enhancement of the interlayer excitons, even at room temperature, due to their commensurate structure with aligned momentum coordinates. Our work not only demonstrates a way to fabricate zero-twisted, two-dimensional bilayers with R- and H-type configurations, but also provides a platform for studying their unexplored properties.
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Affiliation(s)
- Ji-Hwan Baek
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Hyoung Gyun Kim
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Soo Yeon Lim
- Department of Physics, Sogang University, Seoul, Korea
| | - Seong Chul Hong
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Yunyeong Chang
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Huije Ryu
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Yeonjoon Jung
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Hajung Jang
- Department of Physics, Sogang University, Seoul, Korea
| | - Jungcheol Kim
- Department of Physics, Sogang University, Seoul, Korea
| | - Yichao Zhang
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana-Champaign, IL, USA
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Pinshane Y Huang
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana-Champaign, IL, USA
| | | | - Miyoung Kim
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Gwan-Hyoung Lee
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea.
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37
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Zhang S, Sun D, Sun J, Ma K, Wei Z, Park JY, Coffey AH, Zhu C, Dou L, Huang L. Unraveling the Effect of Stacking Configurations on Charge Transfer in WS 2 and Organic Semiconductor Heterojunctions. PRECISION CHEMISTRY 2023; 1:443-451. [PMID: 37771515 PMCID: PMC10526440 DOI: 10.1021/prechem.3c00057] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 06/06/2023] [Accepted: 06/08/2023] [Indexed: 09/30/2023]
Abstract
Photoinduced interfacial charge transfer plays a critical role in energy conversion involving van der Waals (vdW) heterostructures constructed of inorganic nanostructures and organic materials. However, the effect of molecular stacking configurations on charge transfer dynamics is less understood. In this study, we demonstrated the tunability of interfacial charge separation in a type-II heterojunction between monolayer (ML) WS2 and an organic semiconducting molecule [2-(3″',4'-dimethyl-[2,2':5',2':5″,2″'-quaterthiophen]-5-yl)ethan-1-ammonium halide (4Tm)] by rational design of relative stacking configurations. The assembly between ML-WS2 and the 4Tm molecule forms a face-to-face stacking when 4Tm molecules are in a self-aggregation state. In contrast, a face-to-edge stacking is observed when 4Tm molecule is incorporated into a 2D organic-inorganic hybrid perovskite lattice. The face-to-face stacking was proved to be more favorable for hole transfer from WS2 to 4Tm and led to interlayer excitons (IEs) emission. Transient absorption measurements show that the hole transfer occurs on a time scale of 150 fs. On the other hand, the face-to-edge stacking resulted in much slower hole transfer without formation of IEs. This inefficient hole transfer occurs on a similar time scale as A exciton recombination in WS2, leading to the formation of negative trions. These investigations offer important fundamental insights into the charge transfer processes at organic-inorganic interfaces.
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Affiliation(s)
- Shuchen Zhang
- Davidson
School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Dewei Sun
- Department
of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jiaonan Sun
- Davidson
School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Ke Ma
- Davidson
School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Zitang Wei
- Davidson
School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jee Yung Park
- Davidson
School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Aidan H. Coffey
- Advanced
Light Source, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Chenhui Zhu
- Advanced
Light Source, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Letian Dou
- Davidson
School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck
Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Libai Huang
- Department
of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
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38
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Sebait R, Rosati R, Yun SJ, Dhakal KP, Brem S, Biswas C, Puretzky A, Malic E, Lee YH. Sequential order dependent dark-exciton modulation in bi-layered TMD heterostructure. Nat Commun 2023; 14:5548. [PMID: 37684279 PMCID: PMC10491585 DOI: 10.1038/s41467-023-41047-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
We report the emergence of dark-excitons in transition-metal-dichalcogenide (TMD) heterostructures that strongly rely on the stacking sequence, i.e., momentum-dark K-Q exciton located exclusively at the top layer of the heterostructure. The feature stems from band renormalization and is distinct from those of typical neutral excitons or trions, regardless of materials, substrates, and even homogeneous bilayers, which is further confirmed by scanning tunneling spectroscopy. To understand the unusual stacking sequence, we introduce the excitonic Elliot formula by imposing strain exclusively on the top layer that could be a consequence of the stacking process. We further find that the intensity ratio of Q- to K-excitons in the same layer is inversely proportional to laser power, unlike for conventional K-K excitons. This can be a metric for engineering the intensity of dark K-Q excitons in TMD heterostructures, which could be useful for optical power switches in solar panels.
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Affiliation(s)
- Riya Sebait
- Deparment of Energy Science (DOES), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Roberto Rosati
- Department of Physics, Philipps-Universität Marburg, Marburg, 35032, Germany
| | - Seok Joon Yun
- Center for Nanophase Materials Sciences (CNMS), Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Krishna P Dhakal
- Deparment of Energy Science (DOES), Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Samuel Brem
- Department of Physics, Philipps-Universität Marburg, Marburg, 35032, Germany
| | - Chandan Biswas
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Alexander Puretzky
- Center for Nanophase Materials Sciences (CNMS), Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Ermin Malic
- Department of Physics, Philipps-Universität Marburg, Marburg, 35032, Germany.
| | - Young Hee Lee
- Deparment of Energy Science (DOES), Sungkyunkwan University, Suwon, 16419, Republic of Korea.
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea.
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39
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Yuan L, Zheng B, Zhao Q, Kempt R, Brumme T, Kuc AB, Ma C, Deng S, Pan A, Huang L. Strong Dipolar Repulsion of One-Dimensional Interfacial Excitons in Monolayer Lateral Heterojunctions. ACS NANO 2023; 17:15379-15387. [PMID: 37540827 DOI: 10.1021/acsnano.2c12903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/06/2023]
Abstract
Repulsive and long-range exciton-exciton interactions are crucial for the exploration of one-dimensional (1D) correlated quantum phases in the solid state. However, the experimental realization of nanoscale confinement of a 1D dipolar exciton has thus far been limited. Here, we demonstrate atomically precise lateral heterojunctions based at transitional-metal dichalcogenides (TMDCs) as a platform for 1D dipolar excitons. The dynamics and transport of the interfacial charge transfer excitons in a type II WSe2-WS1.16Se0.84 lateral heterostructure were spatially and temporally imaged using ultrafast transient reflection microscopy. The expansion of the exciton cloud driven by dipolar repulsion was found to be strongly density dependent and highly anisotropic. The interaction strength between the 1D excitons was determined to be ∼3.9 × 10-14 eV cm-2, corresponding to a dipolar length of 310 nm, which is a factor of 2-3 larger than the interlayer excitons at two-dimensional van der Waals vertical interfaces. These results suggest 1D dipolar excitons with large static in-plane dipole moments in lateral TMDC heterojunctions as an exciting system for investigating quantum many-body physics.
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Affiliation(s)
- Long Yuan
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47906, United States
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230052, China
| | - Biyuan Zheng
- College of Materials Science and Engineering, Hunan University, Changsha, Hunan 410012, China
| | - Qiuchen Zhao
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47906, United States
| | - Roman Kempt
- Technische Universitat Dresden, 01062 Dresden, Germany
| | - Thomas Brumme
- Technische Universitat Dresden, 01062 Dresden, Germany
| | - Agnieszka B Kuc
- Helmholtz-Zentrum Dresden-Rossendorf, Abteilung Ressourcenökologie, Forschungsstelle Leipzig, Permoserstraße 15, 04318 Leipzig, Germany
| | - Chao Ma
- College of Materials Science and Engineering, Hunan University, Changsha, Hunan 410012, China
| | - Shibin Deng
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47906, United States
| | - Anlian Pan
- College of Materials Science and Engineering, Hunan University, Changsha, Hunan 410012, China
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, Changsha, Hunan 410012, China
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Changsha, Hunan 410012, China
| | - Libai Huang
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47906, United States
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40
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Meng F, Yang X, Gao J. Phonon-assisted upconversion photoluminescence of monolayer MoS 2 at elevated temperatures. OPTICS EXPRESS 2023; 31:28437-28443. [PMID: 37710897 DOI: 10.1364/oe.495824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 08/03/2023] [Indexed: 09/16/2023]
Abstract
Upconversion photoluminescence (UPL) lies at the heart of optical refrigeration and energy harvesting. Monolayer transition metal dichalcogenides (TMDCs) have been identified as an excellent platform with robust phonon-exciton coupling for studying the phonon-assisted UPL process. Herein, we investigate the multiphonon-assisted UPL emission in monolayer MoS2 at elevated temperatures and the temperature-dependent phonon contributions in the UPL process. When temperature goes up from 295 K to 460 K, the enhancement of the integrated UPL intensity is demonstrated due to the increased phonon population and the reduced phonon numbers involved in the UPL process. Our findings reveal the underlying mechanism of phonon-assisted UPL at high temperatures, and pave the way for the applications of photon upconversion in display, nanoscale thermometry, anti-Stokes energy harvesting, and optical refrigeration.
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41
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Hsieh YC, Lin ZY, Fung SJ, Lu WS, Ho SC, Hong SP, Ho SZ, Huang CH, Watanabe K, Taniguchi T, Chan YH, Chen YC, Wu CL, Chen TM. Engineering the Strain and Interlayer Excitons of 2D Materials via Lithographically Engraved Hexagonal Boron Nitride. NANO LETTERS 2023; 23:7244-7251. [PMID: 37348137 DOI: 10.1021/acs.nanolett.3c01208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
Strain engineering has quickly emerged as a viable option to modify the electronic, optical, and magnetic properties of 2D materials. However, it remains challenging to arbitrarily control the strain. Here we show that, by creating atomically flat surface nanostructures in hexagonal boron nitride, we achieve an arbitrary on-chip control of both the strain distribution and magnitude on high-quality molybdenum disulfide. The phonon and exciton emissions are shown to vary in accordance with our strain field designs, enabling us to write and draw any photoluminescence color image in a single chip. Moreover, our strain engineering offers a powerful means to significantly and controllably alter the strengths and energies of interlayer excitons at room temperature. This method can be easily extended to other material systems and offers promise for functional excitonic devices.
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Affiliation(s)
- Yu-Chiang Hsieh
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Zhen-You Lin
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Shin-Ji Fung
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Wen-Shin Lu
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Sheng-Chin Ho
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Siang-Ping Hong
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Sheng-Zhu Ho
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Chiu-Hua Huang
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Namiki 1-1, Tsukuba, 305-0044, Ibaraki, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Namiki 1-1, Tsukuba, 305-0044, Ibaraki, Japan
| | - Yang-Hao Chan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan
- Physics Division, National Center for Theoretical Sciences, Taipei 106, Taiwan
| | - Yi-Chun Chen
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan 701, Taiwan
| | - Chung-Lin Wu
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan 701, Taiwan
| | - Tse-Ming Chen
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan 701, Taiwan
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42
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Chatterjee S, Dandu M, Dasika P, Biswas R, Das S, Watanabe K, Taniguchi T, Raghunathan V, Majumdar K. Harmonic to anharmonic tuning of moiré potential leading to unconventional Stark effect and giant dipolar repulsion in WS 2/WSe 2 heterobilayer. Nat Commun 2023; 14:4679. [PMID: 37542024 PMCID: PMC10403536 DOI: 10.1038/s41467-023-40329-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 07/24/2023] [Indexed: 08/06/2023] Open
Abstract
Excitonic states trapped in harmonic moiré wells of twisted heterobilayers is an intriguing testbed for exploring many-body physics. However, the moiré potential is primarily governed by the twist angle, and its dynamic tuning remains a challenge. Here we demonstrate anharmonic tuning of moiré potential in a WS2/WSe2 heterobilayer through gate voltage and optical power. A gate voltage can result in a local in-plane perturbing field with odd parity around the high-symmetry points. This allows us to simultaneously observe the first (linear) and second (parabolic) order Stark shift for the ground state and first excited state, respectively, of the moiré trapped exciton - an effect opposite to conventional quantum-confined Stark shift. Depending on the degree of confinement, these excitons exhibit up to twenty-fold gate-tunability in the lifetime (100 to 5 ns). Also, exciton localization dependent dipolar repulsion leads to an optical power-induced blueshift of ~ 1 meV/μW - a five-fold enhancement over previous reports.
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Affiliation(s)
- Suman Chatterjee
- Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore, 560012, India
| | - Medha Dandu
- Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore, 560012, India
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Pushkar Dasika
- Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore, 560012, India
| | - Rabindra Biswas
- Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore, 560012, India
| | - Sarthak Das
- Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore, 560012, India
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, 138634, Republic of Singapore
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-044, Japan
| | - Varun Raghunathan
- Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore, 560012, India
| | - Kausik Majumdar
- Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore, 560012, India.
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43
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Liu W, Zheng X, Xu Q. Supercritical CO 2 Directional-Assisted Synthesis of Low-Dimensional Materials for Functional Applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2301097. [PMID: 37093220 DOI: 10.1002/smll.202301097] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/07/2023] [Indexed: 05/03/2023]
Abstract
Supercritical CO2 (SC CO2 ), as one of the unique fluids that possess fascinating properties of gas and liquid, holds great promise in chemical reactions and fabrication of materials. Building special nanostructures via SC CO2 for functional applications has been the focus of intense research for the past two decades, with facile regulated reaction conditions and a particular reaction field to operate compared to the more widely used solvent systems. In this review, the significance of SC CO2 on fabricating various functional materials including modification of 1D carbon nanotubes, 2D materials, and 2D heterostructures is stated. The fundamental aspects involving building special nanostructures via SC CO2 are explored: how their structure, morphology, and chemical composition be affected by the SC CO2 . Various optimization strategies are outlined to improve their performances, and recent advances are combined to present a coherent understanding of the mechanism of SC CO2 acting on these functional nanostructures. The wide applications of these special nanostructures in catalysis, biosensing, optoelectronics, microelectronics, and energy transformation are discussed. Moreover, the current status of SC CO2 research, the existing scientific issues, and application challenges, as well as the possible future directions to advance this fertile field are proposed in this review.
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Affiliation(s)
- Wei Liu
- Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou, 450052, P. R. China
| | - Xiaoli Zheng
- College of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China
| | - Qun Xu
- Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou, 450052, P. R. China
- College of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China
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44
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Kim H, Dong D, Okamura Y, Shinokita K, Watanabe K, Taniguchi T, Matsuda K. Dynamics of Moiré Trion and Its Valley Polarization in a Microfabricated WSe 2/MoSe 2 Heterobilayer. ACS NANO 2023. [PMID: 37450661 DOI: 10.1021/acsnano.3c02952] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
The moiré potential, induced by stacking two monolayer semiconductors with slightly different lattice mismatches, acts as periodic quantum confinement for optically generated excitons, resulting in spatially ordered zero-dimensional quantum systems. However, there are limitations to exploring intrinsic optical properties of moiré excitons due to ensemble emissions and broadened emissions from many peaks caused by the inhomogeneity of the moiré potential. In this study, we proposed a microfabrication technique based on focused Ga+ ion beams, which enables us to control the number of peaks originating from the moiré potential and thus explore unknown moiré optical characteristics of WSe2/MoSe2 heterobilayer. By taking advantage of this approach, we reveal emissions from a single moiré exciton and charged moiré exciton (trion) under electrostatic doping conditions. We show the momentum dark moiré trion state above the bright trion state with a splitting energy of approximately 4 meV and clarify that the dynamics are determined by the initial trion population in the bright state. Furthermore, the degree of negative circularly polarized emissions and their valley dynamics of moiré trions are dominated by a very long valley relaxation process lasting ∼700 ns. Our findings on microfabricated heterobilayer could be viewed as an extension of our groundbreaking efforts in the field of quantum optics application using moiré superlattices.
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Affiliation(s)
- Heejun Kim
- Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Duanfei Dong
- Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Yuki Okamura
- Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Keisuke Shinokita
- Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Kazunari Matsuda
- Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan
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45
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Erkensten D, Brem S, Perea-Causín R, Hagel J, Tagarelli F, Lopriore E, Kis A, Malic E. Electrically tunable dipolar interactions between layer-hybridized excitons. NANOSCALE 2023; 15:11064-11071. [PMID: 37309577 PMCID: PMC10324325 DOI: 10.1039/d3nr01049j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/02/2023] [Indexed: 06/14/2023]
Abstract
Transition-metal dichalcogenide bilayers exhibit a rich exciton landscape including layer-hybridized excitons, i.e. excitons which are of partly intra- and interlayer nature. In this work, we study hybrid exciton-exciton interactions in naturally stacked WSe2 homobilayers. In these materials, the exciton landscape is electrically tunable such that the low-energy states can be rendered more or less interlayer-like depending on the strength of the external electric field. Based on a microscopic and material-specific many-particle theory, we reveal two intriguing interaction regimes: a low-dipole regime at small electric fields and a high-dipole regime at larger fields, involving interactions between hybrid excitons with a substantially different intra- and interlayer composition in the two regimes. While the low-dipole regime is characterized by weak inter-excitonic interactions between intralayer-like excitons, the high-dipole regime involves mostly interlayer-like excitons which display a strong dipole-dipole repulsion and give rise to large spectral blue-shifts and a highly anomalous diffusion. Overall, our microscopic study sheds light on the remarkable electrical tunability of hybrid exciton-exciton interactions in atomically thin semiconductors and can guide future experimental studies in this growing field of research.
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Affiliation(s)
- Daniel Erkensten
- Department of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden.
| | - Samuel Brem
- Department of Physics, Philipps-Universität Marburg, 35037 Marburg, Germany
| | - Raül Perea-Causín
- Department of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden.
| | - Joakim Hagel
- Department of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden.
| | - Fedele Tagarelli
- Institute of Electrical and Microengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Institute of Materials Science and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Edoardo Lopriore
- Institute of Electrical and Microengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Institute of Materials Science and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Andras Kis
- Institute of Electrical and Microengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Institute of Materials Science and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Ermin Malic
- Department of Physics, Philipps-Universität Marburg, 35037 Marburg, Germany
- Department of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden.
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46
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Malic E, Perea-Causin R, Rosati R, Erkensten D, Brem S. Exciton transport in atomically thin semiconductors. Nat Commun 2023; 14:3430. [PMID: 37301820 DOI: 10.1038/s41467-023-38556-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 05/09/2023] [Indexed: 06/12/2023] Open
Affiliation(s)
- Ermin Malic
- Department of Physics, Philipps-Universität Marburg, 35032, Marburg, Germany.
| | - Raül Perea-Causin
- Department of Physics, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Roberto Rosati
- Department of Physics, Philipps-Universität Marburg, 35032, Marburg, Germany
| | - Daniel Erkensten
- Department of Physics, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Samuel Brem
- Department of Physics, Philipps-Universität Marburg, 35032, Marburg, Germany
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47
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Chen J, Yue X, Shan Y, Wang H, Han J, Wang H, Sheng C, Hu L, Liu R, Yang W, Qiu ZJ, Cong C. Twist-angle-dependent momentum-space direct and indirect interlayer excitons in WSe 2/WS 2 heterostructure. RSC Adv 2023; 13:18099-18107. [PMID: 37323440 PMCID: PMC10267672 DOI: 10.1039/d3ra02952b] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 05/29/2023] [Indexed: 06/17/2023] Open
Abstract
Interlayer excitons (ILEs) in the van der Waals (vdW) heterostructures of type-II band alignment transition metal dichalcogenides (TMDCs) have attracted significant interest owing to their unique exciton properties and potential in quantum information applications. However, the new dimension that emerges with the stacking of structures with a twist angle leads to a more complex fine structure of ILEs, presenting both an opportunity and a challenge for the regulation of the interlayer excitons. In this study, we report the evolution of interlayer excitons with the twist angle in the WSe2/WS2 heterostructure and identify the direct (indirect) interlayer excitons by combining photoluminescence (PL) and density functional theory (DFT) calculations. Two interlayer excitons with opposite circular polarization assigned to the different transition paths of K-K and Q-K were observed. The nature of the direct (indirect) interlayer exciton was confirmed by circular polarization PL measurement, excitation power-dependent PL measurement and DFT calculations. Furthermore, by applying an external electric field to regulate the band structure of the WSe2/WS2 heterostructure and control the transition path of the interlayer excitons, we could successfully realize the regulation of interlayer exciton emission. This study provides more evidence for the twist-angle-based control of heterostructure properties.
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Affiliation(s)
- Jiajun Chen
- State Key Laboratory of ASIC & System, School of Information Science and Technology, Fudan University Shanghai 200433 China
| | - Xiaofei Yue
- State Key Laboratory of ASIC & System, School of Information Science and Technology, Fudan University Shanghai 200433 China
| | - Yabing Shan
- State Key Laboratory of ASIC & System, School of Information Science and Technology, Fudan University Shanghai 200433 China
| | - Huishan Wang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences Changning Road 865 Shanghai 200050 China
| | - Jinkun Han
- State Key Laboratory of ASIC & System, School of Information Science and Technology, Fudan University Shanghai 200433 China
| | - Haomin Wang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences Changning Road 865 Shanghai 200050 China
| | - Chenxu Sheng
- State Key Laboratory of ASIC & System, School of Information Science and Technology, Fudan University Shanghai 200433 China
| | - Laigui Hu
- State Key Laboratory of ASIC & System, School of Information Science and Technology, Fudan University Shanghai 200433 China
| | - Ran Liu
- State Key Laboratory of ASIC & System, School of Information Science and Technology, Fudan University Shanghai 200433 China
| | - Weihuang Yang
- Engineering Research Center of Smart Microsensors and Microsystems, Ministry of Education, College of Electronics and Information, Hangzhou Dianzi University Hangzhou 310018 China
| | - Zhi-Jun Qiu
- State Key Laboratory of ASIC & System, School of Information Science and Technology, Fudan University Shanghai 200433 China
| | - Chunxiao Cong
- State Key Laboratory of ASIC & System, School of Information Science and Technology, Fudan University Shanghai 200433 China
- Yiwu Research Institute of Fudan University Chengbei Road Yiwu City 322000 Zhejiang China
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48
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Dziobek-Garrett R, Imperiale CJ, Wilson MWB, Kempa TJ. Photon Upconversion in a Vapor Deposited 2D Inorganic-Organic Semiconductor Heterostructure. NANO LETTERS 2023. [PMID: 37191568 DOI: 10.1021/acs.nanolett.3c00380] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Energy transfer processes may be engineered in van der Waals heterostructures by taking advantage of the atomically abrupt, Å-scale, and topologically tailorable interfaces within them. Here, we prepare heterostructures comprised of 2D WSe2 monolayers interfaced with dibenzotetraphenylperiflanthene (DBP)-doped rubrene, an organic semiconductor capable of triplet fusion. We fabricate these heterostructures entirely through vapor deposition methods. Time-resolved and steady-state photoluminescence measurements reveal rapid subnanosecond quenching of WSe2 emission by rubrene and fluorescence from guest DBP molecules at 612 nm (λexc = 730 nm), thus providing clear evidence of photon upconversion. The dependence of the upconversion emission on excitation intensity is consistent with a triplet fusion mechanism, and maximum efficiency (linear regime) of this process occurs at threshold intensities as low as 110 mW/cm2, which is comparable to the integrated solar irradiance. This study highlights the potential for advanced optoelectronic applications employing vdWHs which leverage strongly bound excitons in monolayer TMDs and organic semiconductors.
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Affiliation(s)
| | | | - Mark W B Wilson
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Thomas J Kempa
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Department of Materials Science & Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
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49
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Choi J, Embley J, Blach DD, Perea-Causín R, Erkensten D, Kim DS, Yuan L, Yoon WY, Taniguchi T, Watanabe K, Ueno K, Tutuc E, Brem S, Malic E, Li X, Huang L. Fermi Pressure and Coulomb Repulsion Driven Rapid Hot Plasma Expansion in a van der Waals Heterostructure. NANO LETTERS 2023; 23:4399-4405. [PMID: 37154560 DOI: 10.1021/acs.nanolett.3c00678] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Transition metal dichalcogenide heterostructures provide a versatile platform to explore electronic and excitonic phases. As the excitation density exceeds the critical Mott density, interlayer excitons are ionized into an electron-hole plasma phase. The transport of the highly non-equilibrium plasma is relevant for high-power optoelectronic devices but has not been carefully investigated previously. Here, we employ spatially resolved pump-probe microscopy to investigate the spatial-temporal dynamics of interlayer excitons and hot-plasma phase in a MoSe2/WSe2 twisted bilayer. At the excitation density of ∼1014 cm-2, well exceeding the Mott density, we find a surprisingly rapid initial expansion of hot plasma to a few microns away from the excitation source within ∼0.2 ps. Microscopic theory reveals that this rapid expansion is mainly driven by Fermi pressure and Coulomb repulsion, while the hot carrier effect has only a minor effect in the plasma phase.
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Affiliation(s)
- Junho Choi
- Department of Physics and Center for Complex Quantum Systems, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Jacob Embley
- Department of Physics and Center for Complex Quantum Systems, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Daria D Blach
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2050, United States
| | - Raül Perea-Causín
- Department of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden
| | - Daniel Erkensten
- Department of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden
| | - Dong Seob Kim
- Department of Physics and Center for Complex Quantum Systems, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Long Yuan
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2050, United States
| | - Woo Young Yoon
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Keiji Ueno
- Department of Chemistry, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Emanuel Tutuc
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Samuel Brem
- Department of Physics, Philipps University of Marburg, 35037 Marburg, Germany
| | - Ermin Malic
- Department of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden
- Department of Physics, Philipps University of Marburg, 35037 Marburg, Germany
| | - Xiaoqin Li
- Department of Physics and Center for Complex Quantum Systems, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Libai Huang
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2050, United States
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50
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Li Z, Tabataba-Vakili F, Zhao S, Rupp A, Bilgin I, Herdegen Z, März B, Watanabe K, Taniguchi T, Schleder GR, Baimuratov AS, Kaxiras E, Müller-Caspary K, Högele A. Lattice Reconstruction in MoSe 2-WSe 2 Heterobilayers Synthesized by Chemical Vapor Deposition. NANO LETTERS 2023; 23:4160-4166. [PMID: 37141148 DOI: 10.1021/acs.nanolett.2c05094] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Vertical van der Waals heterostructures of semiconducting transition metal dichalcogenides realize moiré systems with rich correlated electron phases and moiré exciton phenomena. For material combinations with small lattice mismatch and twist angles as in MoSe2-WSe2, however, lattice reconstruction eliminates the canonical moiré pattern and instead gives rise to arrays of periodically reconstructed nanoscale domains and mesoscopically extended areas of one atomic registry. Here, we elucidate the role of atomic reconstruction in MoSe2-WSe2 heterostructures synthesized by chemical vapor deposition. With complementary imaging down to the atomic scale, simulations, and optical spectroscopy methods, we identify the coexistence of moiré-type cores and extended moiré-free regions in heterostacks with parallel and antiparallel alignment. Our work highlights the potential of chemical vapor deposition for applications requiring laterally extended heterosystems of one atomic registry or exciton-confining heterostack arrays.
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Affiliation(s)
- Zhijie Li
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539 München, Germany
| | - Farsane Tabataba-Vakili
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539 München, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingtraße 4, 80799 München, Germany
| | - Shen Zhao
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539 München, Germany
| | - Anna Rupp
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539 München, Germany
| | - Ismail Bilgin
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539 München, Germany
| | - Ziria Herdegen
- Department of Chemistry and Center for NanoScience, Ludwig-Maximilians-Universität München, Butenandtstraße 11, 81377 München, Germany
| | - Benjamin März
- Department of Chemistry and Center for NanoScience, Ludwig-Maximilians-Universität München, Butenandtstraße 11, 81377 München, Germany
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Gabriel Ravanhani Schleder
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Anvar S Baimuratov
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539 München, Germany
| | - Efthimios Kaxiras
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Knut Müller-Caspary
- Department of Chemistry and Center for NanoScience, Ludwig-Maximilians-Universität München, Butenandtstraße 11, 81377 München, Germany
| | - Alexander Högele
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539 München, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingtraße 4, 80799 München, Germany
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