1
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Lin Q, Fang H, Kalaboukhov A, Liu Y, Zhang Y, Fischer M, Li J, Hagel J, Brem S, Malic E, Stenger N, Sun Z, Wubs M, Xiao S. Moiré-engineered light-matter interactions in MoS 2/WSe 2 heterobilayers at room temperature. Nat Commun 2024; 15:8762. [PMID: 39384821 PMCID: PMC11464769 DOI: 10.1038/s41467-024-53083-x] [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: 04/10/2024] [Accepted: 09/26/2024] [Indexed: 10/11/2024] Open
Abstract
Moiré superlattices in van der Waals heterostructures represent a highly tunable quantum system, attracting substantial interest in both many-body physics and device applications. However, the influence of the moiré potential on light-matter interactions at room temperature has remained largely unexplored. In our study, we demonstrate that the moiré potential in MoS2/WSe2 heterobilayers facilitates the localization of interlayer exciton (IX) at room temperature. By performing reflection contrast spectroscopy, we demonstrate the importance of atomic reconstruction in modifying intralayer excitons, supported by the atomic force microscopy experiment. When decreasing the twist angle, we observe that the IX lifetime becomes longer and light emission gets enhanced, indicating that non-radiative decay channels such as defects are suppressed by the moiré potential. Moreover, through the integration of moiré superlattices with silicon single-mode cavities, we find that the devices employing moiré-trapped IXs exhibit a significantly lower threshold, one order of magnitude smaller compared to the device utilizing delocalized IXs. These findings not only encourage the exploration of many-body physics in moiré superlattices at elevated temperatures but also pave the way for leveraging these artificial quantum materials in photonic and optoelectronic applications.
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Affiliation(s)
- Qiaoling Lin
- Department of Electrical and Photonics Engineering, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
- NanoPhoton - Center for Nanophotonics, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
- Centre for Nanostructured Graphene, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
| | - Hanlin Fang
- Department of Electrical and Photonics Engineering, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark.
- NanoPhoton - Center for Nanophotonics, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark.
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, 41296, Gothenburg, Sweden.
| | - Alexei Kalaboukhov
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Yuanda Liu
- Institute of Materials Research and Engineering, Agency for Science Technology and Research (A*STAR), 2 Fusionopolis Way, 138634, Singapore, Singapore
| | - Yi Zhang
- Department of Electronics and Nanoengineering and QTF Centre of Excellence, Aalto University, Espoo, 02150, Finland
| | - Moritz Fischer
- Department of Electrical and Photonics Engineering, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
- NanoPhoton - Center for Nanophotonics, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
- Centre for Nanostructured Graphene, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
| | - Juntao Li
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Joakim Hagel
- Department of Physics, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Samuel Brem
- Department of Physics, Philipps-Universität Marburg, 35037, Marburg, Germany
| | - Ermin Malic
- Department of Physics, Philipps-Universität Marburg, 35037, Marburg, Germany
| | - Nicolas Stenger
- Department of Electrical and Photonics Engineering, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
- NanoPhoton - Center for Nanophotonics, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
- Centre for Nanostructured Graphene, 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
| | - Martijn Wubs
- Department of Electrical and Photonics Engineering, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
- NanoPhoton - Center for Nanophotonics, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
- Centre for Nanostructured Graphene, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
| | - Sanshui Xiao
- Department of Electrical and Photonics Engineering, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark.
- NanoPhoton - Center for Nanophotonics, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark.
- Centre for Nanostructured Graphene, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark.
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2
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Fu Q, Liu X, Wang S, Wu Z, Xia W, Zhang Q, Ni Z, Hu Z, Lu J. Room-temperature efficient and tunable interlayer exciton emissions in WS 2/WSe 2 heterobilayers at high generation rates. OPTICS LETTERS 2024; 49:5196-5199. [PMID: 39270262 DOI: 10.1364/ol.534473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2024] [Accepted: 08/21/2024] [Indexed: 09/15/2024]
Abstract
Transition metal dichalcogenide (TMDC) heterobilayers (HBs) have been intensively investigated lately because they offer novel platforms for the exploration of interlayer excitons (IXs). However, the potentials of IXs in TMDC HBs have not been fully studied as efficient and tunable emitters for both photoluminescence (PL) and electroluminescence (EL) at room temperature (RT). Also, the efficiencies of the PL and EL of IXs have not been carefully quantified. In this work, we demonstrate that IX in WS2/WSe2 HBs could serve as promising emitters at high generation rates due to its immunity to efficiency roll-off. Furthermore, by applying gate voltages to balance the electron and hole concentrations and to reinforce the built-in electric fields, high PL quantum yield (QY) and EL external quantum efficiency (EQE) of ∼0.48% and ∼0.11% were achieved at RT, respectively, with generation rates exceeding 1021 cm-2·s-1, which confirms the capabilities of IXs as efficient NIR light emitters by surpassing most of the intralayer emissions from TMDCs.
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3
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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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4
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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; 36: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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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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Wang A, Wu X, Zhao S, Han ZV, Shi Y, Cerullo G, Wang F. Electrically tunable non-radiative lifetime in WS 2/WSe 2 heterostructures. NANOSCALE 2024; 16:13687-13693. [PMID: 38967228 DOI: 10.1039/d4nr01982b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/06/2024]
Abstract
Van der Waals heterostructures based on transition metal dichalcogenides (TMDs) have emerged as excellent candidates for next-generation optoelectronics and valleytronics, due to their fascinating physical properties. The understanding and active control of the relaxation dynamics of heterostructures play a crucial role in device design and optimization. Here, we investigate the back-gate modulation of exciton dynamics in a WS2/WSe2 heterostructure by combining time-resolved photoluminescence (TRPL) and transient absorption spectroscopy (TAS) at cryogenic temperatures. We find that the non-radiative relaxation lifetimes of photocarriers in heterostructures can be electrically controlled for samples with different twist-angles, whereas such lifetime tuning is not present in standalone monolayers. We attribute such an observation to doping-controlled competition between interlayer and intralayer recombination pathways in high-quality WS2/WSe2 samples. The simultaneous measurement of TRPL and TAS lifetimes within the same sample provides additional insight into the influence of coexisting excitons and background carriers on the photo-response, and points to the potential of tailoring light-matter interactions in TMD heterostructures.
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Affiliation(s)
- Anran Wang
- School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
| | - Xingguang Wu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Siwen Zhao
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Zheng Vitto Han
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006, China
| | - Yi Shi
- School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
| | - Giulio Cerullo
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
- Istituto di Fotonica e Nanotecnologie (IFN), CNR, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Fengqiu Wang
- School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
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7
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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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8
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Rahaman M, Marino E, Joly AG, Stevens CE, Song S, Alfieri A, Jiang Z, O'Callahan BT, Rosen DJ, Jo K, Kim G, Hendrickson JR, El-Khoury PZ, Murray C, Jariwala D. Tunable Localized Charge Transfer Excitons in Nanoplatelet-2D Chalcogenide van der Waals Heterostructures. ACS NANO 2024; 18:15185-15193. [PMID: 38809690 DOI: 10.1021/acsnano.4c03260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Observation of interlayer, charge transfer (CT) excitons in van der Waals heterostructures (vdWHs) based on 2D-2D systems has been well investigated. While conceptually interesting, these charge transfer excitons are highly delocalized and spatially localizing them requires twisting layers at very specific angles. This issue of localizing the CT excitons can be overcome via making nanoplate-2D material heterostructures (N2DHs) where one of the components is a spatially quantum confined medium. Here, we demonstrate the formation of CT excitons in a mixed dimensional system comprising MoSe2 and WSe2 monolayers and CdSe/CdS-based core/shell nanoplates (NPLs). Spectral signatures of CT excitons in our N2DHs were resolved locally at the 2D/single-NPL heterointerface using tip-enhanced photoluminescence (TEPL) at room temperature. By varying both the 2D material and the shell thickness of the NPLs and applying an out-of-plane electric field, the exciton resonance energy was tuned by up to 100 meV. Our finding is a significant step toward the realization of highly tunable N2DH-based next-generation photonic devices.
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Affiliation(s)
- Mahfujur Rahaman
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Emanuele Marino
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Via Archirafi 36, 90123 Palermo, Italy
| | - Alan G Joly
- Physical and Chemical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Christopher E Stevens
- Sensors Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433, United States
- KBR Inc., Beavercreek, Ohio 45431, United States
| | - Seunguk Song
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Adam Alfieri
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Zhiqiao Jiang
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Brian T O'Callahan
- Physical and Chemical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Daniel J Rosen
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Kiyoung Jo
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Gwangwoo Kim
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Joshua R Hendrickson
- Sensors Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433, United States
| | - Patrick Z El-Khoury
- Physical and Chemical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Christopher Murray
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Deep Jariwala
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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9
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Huang Z, Bai Y, Zhao Y, Liu L, Zhao X, Wu J, Watanabe K, Taniguchi T, Yang W, Shi D, Xu Y, Zhang T, Zhang Q, Tan PH, Sun Z, Meng S, Wang Y, Du L, Zhang G. Observation of phonon Stark effect. Nat Commun 2024; 15:4586. [PMID: 38811589 PMCID: PMC11137145 DOI: 10.1038/s41467-024-48992-w] [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: 01/03/2024] [Accepted: 05/15/2024] [Indexed: 05/31/2024] Open
Abstract
Stark effect, the electric-field analogue of magnetic Zeeman effect, is one of the celebrated phenomena in modern physics and appealing for emergent applications in electronics, optoelectronics, as well as quantum technologies. While in condensed matter it has prospered only for excitons, whether other collective excitations can display Stark effect remains elusive. Here, we report the observation of phonon Stark effect in a two-dimensional quantum system of bilayer 2H-MoS2. The longitudinal acoustic phonon red-shifts linearly with applied electric fields and can be tuned over ~1 THz, evidencing giant Stark effect of phonons. Together with many-body ab initio calculations, we uncover that the observed phonon Stark effect originates fundamentally from the strong coupling between phonons and interlayer excitons (IXs). In addition, IX-mediated electro-phonon intensity modulation up to ~1200% is discovered for infrared-active phonon A2u. Our results unveil the exotic phonon Stark effect and effective phonon engineering by IX-mediated mechanism, promising for a plethora of exciting many-body physics and potential technological innovations.
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Affiliation(s)
- Zhiheng Huang
- Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Yunfei Bai
- Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Yanchong Zhao
- Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Le Liu
- Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Xuan Zhao
- Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Jiangbin Wu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
| | - 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
| | - Wei Yang
- Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Dongxia Shi
- Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Yang Xu
- Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Tiantian Zhang
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Qingming Zhang
- Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
| | - Ping-Heng Tan
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
| | - Zhipei Sun
- QTF Centre of Excellence, Department of Electronics and Nanoengineering, Aalto University, Tietotie 3, FI-02150, Espoo, Finland
| | - Sheng Meng
- Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong Province, 523808, China
| | - Yaxian Wang
- Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
| | - Luojun Du
- Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China.
| | - Guangyu Zhang
- Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China.
- Songshan Lake Materials Laboratory, Dongguan, Guangdong Province, 523808, China.
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10
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Arnoldi B, Zachritz SL, Hedwig S, Aeschlimann M, Monti OLA, Stadtmüller B. Revealing hidden spin polarization in centrosymmetric van der Waals materials on ultrafast timescales. Nat Commun 2024; 15:3573. [PMID: 38678075 PMCID: PMC11055871 DOI: 10.1038/s41467-024-47821-4] [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: 07/28/2023] [Accepted: 04/12/2024] [Indexed: 04/29/2024] Open
Abstract
One of the key challenges for spintronic and quantum technologies is to achieve active control of the spin angular momentum of electrons in nanoscale materials on ultrafast, femtosecond timescales. While conventional ferromagnetic materials and materials supporting spin texture suffer both from conceptional limitations in miniaturization and inefficiency of optical and electronic manipulation, non-magnetic centrosymmetric layered materials with hidden spin polarization may offer an alternative pathway to manipulate the spin degree of freedom by external stimuli. Here we demonstrate an approach for generating transient spin polarization on a femtosecond timescale in the otherwise spin-unpolarized band structure of the centrosymmetric 2H-stacked group VI transition metal dichalcogenide WSe2. Using ultrafast optical excitation of a fullerene layer grown on top of WSe2, we trigger an ultrafast interlayer electron transfer from the fullerene layer into the WSe2 crystal. The resulting transient charging of the C60/WSe2 interface leads to a substantial interfacial electric field that by means of spin-layer-valley locking ultimately creates ultrafast spin polarization without the need of an external magnetic field. Our findings open a novel pathway for true optical engineering of spin functionalities such as the sub-picosecond generation and manipulation of ultrafast spin currents in 2D heterostructures.
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Affiliation(s)
- B Arnoldi
- Department of Physics and Research Center OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Erwin-Schroedinger-Strasse 46, Kaiserslautern, 67663, Germany
| | - S L Zachritz
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA
| | - S Hedwig
- Department of Physics and Research Center OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Erwin-Schroedinger-Strasse 46, Kaiserslautern, 67663, Germany
| | - M Aeschlimann
- Department of Physics and Research Center OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Erwin-Schroedinger-Strasse 46, Kaiserslautern, 67663, Germany
| | - O L A Monti
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA.
- Department of Physics, University of Arizona, Tucson, AZ, 85721, USA.
| | - B Stadtmüller
- Department of Physics and Research Center OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Erwin-Schroedinger-Strasse 46, Kaiserslautern, 67663, Germany.
- Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128, Mainz, Germany.
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11
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Altman AR, Kundu S, da Jornada FH. Mixed Stochastic-Deterministic Approach for Many-Body Perturbation Theory Calculations. PHYSICAL REVIEW LETTERS 2024; 132:086401. [PMID: 38457735 DOI: 10.1103/physrevlett.132.086401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 08/24/2023] [Accepted: 12/05/2023] [Indexed: 03/10/2024]
Abstract
We present an approach for GW calculations of quasiparticle energies with quasiquadratic scaling by approximating high-energy contributions to the Green's function in its Lehmann representation with effective stochastic vectors. The method is easy to implement without altering the GW code, converges rapidly with stochastic parameters, and treats systems of various dimensionality and screening response. Our calculations on a 5.75° twisted MoS_{2} bilayer show how large-scale GW methods include geometry relaxations and electronic correlations on an equal basis in structurally nontrivial materials.
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Affiliation(s)
- Aaron R Altman
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
| | - Sudipta Kundu
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
| | - Felipe H da Jornada
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
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12
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Ge A, Ge X, Sun L, Lu X, Ma L, Zhao X, Yao B, Zhang X, Zhang T, Jing W, Zhou X, Shen X, Lu W. Unraveling the strain tuning mechanism of interlayer excitons in WSe 2/MoSe 2heterostructure. NANOTECHNOLOGY 2024; 35:175207. [PMID: 38266306 DOI: 10.1088/1361-6528/ad2232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 01/23/2024] [Indexed: 01/26/2024]
Abstract
Atomically thin transition metal dichalcogenides (TMDs) exhibit rich excitonic physics, due to reduced dielectric screening and strong Coulomb interactions. Especially, some attractive topics in modern condensed matter physics, such as correlated insulator, superconductivity, topological excitons bands, are recently reported in stacking two monolayer (ML) TMDs. Here, we clearly reveal the tuning mechanism of tensile strain on interlayer excitons (IEXs) and intralayer excitons (IAXs) in WSe2/MoSe2heterostructure (HS) at low temperature. We utilize the cryogenic tensile strain platform to stretch the HS, and measure by micro-photoluminescence (μ-PL). The PL peaks redshifts of IEXs and IAXs in WSe2/MoSe2HS under tensile strain are well observed. The first-principles calculations by using density functional theory reveals the PL peaks redshifts of IEXs and IAXs origin from bandgap shrinkage. The calculation results also show the Mo-4d states dominating conduction band minimum shifts of the ML MoSe2plays a dominant role in the redshifts of IEXs. This work provides new insights into understanding the tuning mechanism of tensile strain on IEXs and IAXs in two-dimensional (2D) HS, and paves a way to the development of flexible optoelectronic devices based on 2D materials.
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Affiliation(s)
- Anping Ge
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Xun Ge
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, People's Republic of China
| | - Liaoxin Sun
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Xinle Lu
- Key Laboratory of Polar Materials and Devices, Department of Electronics, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Lei Ma
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, People's Republic of China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, People's Republic of China
| | - Xinchao Zhao
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Bimu Yao
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Xin Zhang
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, People's Republic of China
- Department of Physics, Shanghai Normal University, Shanghai, 200234, People's Republic of China
| | - Tao Zhang
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Wenji Jing
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Xiaohao Zhou
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, People's Republic of China
| | - Xuechu Shen
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, People's Republic of China
| | - Wei Lu
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, People's Republic of China
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13
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Bange JP, Schmitt D, Bennecke W, Meneghini G, AlMutairi A, Watanabe K, Taniguchi T, Steil D, Steil S, Weitz RT, Jansen GSM, Hofmann S, Brem S, Malic E, Reutzel M, Mathias S. Probing electron-hole Coulomb correlations in the exciton landscape of a twisted semiconductor heterostructure. SCIENCE ADVANCES 2024; 10:eadi1323. [PMID: 38324690 PMCID: PMC10849592 DOI: 10.1126/sciadv.adi1323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 01/10/2024] [Indexed: 02/09/2024]
Abstract
In two-dimensional semiconductors, cooperative and correlated interactions determine the material's excitonic properties and can even lead to the creation of correlated states of matter. Here, we study the fundamental two-particle correlated exciton state formed by the Coulomb interaction between single-particle holes and electrons. We find that the ultrafast transfer of an exciton's hole across a type II band-aligned semiconductor heterostructure leads to an unexpected sub-200-femtosecond upshift of the single-particle energy of the electron being photoemitted from the two-particle exciton state. While energy relaxation usually leads to an energetic downshift of the spectroscopic signature, we show that this upshift is a clear fingerprint of the correlated interaction of the electron and hole parts of the exciton. In this way, time-resolved photoelectron spectroscopy is straightforwardly established as a powerful method to access electron-hole correlations and cooperative behavior in quantum materials. Our work highlights this capability and motivates the future study of optically inaccessible correlated excitonic and electronic states of matter.
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Affiliation(s)
- Jan Philipp Bange
- I. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - David Schmitt
- I. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Wiebke Bennecke
- I. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Giuseppe Meneghini
- Fachbereich Physik, Philipps-Universität Marburg, 35032 Marburg, 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
| | - Daniel Steil
- I. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Sabine Steil
- I. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - R. Thomas Weitz
- I. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
- International Center for Advanced Studies of Energy Conversion (ICASEC), University of Göttingen, Göttingen, Germany
| | - G. S. Matthijs Jansen
- I. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Stephan Hofmann
- Department of Engineering, University of Cambridge, Cambridge CB3 0FA, UK
| | - Samuel Brem
- Fachbereich Physik, Philipps-Universität Marburg, 35032 Marburg, Germany
| | - Ermin Malic
- Fachbereich Physik, Philipps-Universität Marburg, 35032 Marburg, Germany
- Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Marcel Reutzel
- I. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Stefan Mathias
- I. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
- International Center for Advanced Studies of Energy Conversion (ICASEC), University of Göttingen, Göttingen, Germany
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14
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Hu J, Wen X, Yang D, Chen Y, Liu Z, Li D. Lead-Free Chiral Perovskite for High Degree of Circularly Polarized Light Emission and Spin Injection. NANO LETTERS 2024; 24:1001-1008. [PMID: 38198561 DOI: 10.1021/acs.nanolett.3c04575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
We report a zero-dimensional (0D) lead-free chiral perovskite (S-/R-MBA)4Bi2I10 with a high degree of circularly polarized light (CPL) emission. Our 0D lead-free chiral perovskite exhibits an average degree of circular polarization (DOCP) of 19.8% at 78 K under linearly polarized laser excitation, and the maximum DOCP can reach 25.8%, which is 40 times higher than the highest DOCP of 0.5% in all reported lead-free chiral perovskites to the best of our knowledge. The high DOCP of (S-/R-MBA)4Bi2I10 is attributed to the free exciton emission with a Huang-Rhys factor of 2.8. In contrast, all the lead-free chiral perovskites in prior reports are dominant by self-trapped exciton in which the spin relaxation reduces DOCP dramatically. Moreover, we realize the manipulation of the valley degree of freedom of monolayer WSe2 by using the spin injection of the 0D chiral lead-free perovskites. Our results provide a new perspective to develop lead-free chiral perovskite devices for CPL light source, spintronics, and valleytronics.
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Affiliation(s)
- Junchao Hu
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xinglin Wen
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Dong Yang
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yingying Chen
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zeyi Liu
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Dehui Li
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
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15
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Obaidulla SM, Supina A, Kamal S, Khan Y, Kralj M. van der Waals 2D transition metal dichalcogenide/organic hybridized heterostructures: recent breakthroughs and emerging prospects of the device. NANOSCALE HORIZONS 2023; 9:44-92. [PMID: 37902087 DOI: 10.1039/d3nh00310h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
The near-atomic thickness and organic molecular systems, including organic semiconductors and polymer-enabled hybrid heterostructures, of two-dimensional transition metal dichalcogenides (2D-TMDs) can modulate their optoelectronic and transport properties outstandingly. In this review, the current understanding and mechanism of the most recent and significant breakthrough of novel interlayer exciton emission and its modulation by harnessing the band energy alignment between TMDs and organic semiconductors in a TMD/organic (TMDO) hybrid heterostructure are demonstrated. The review encompasses up-to-date device demonstrations, including field-effect transistors, detectors, phototransistors, and photo-switchable superlattices. An exploration of distinct traits in 2D-TMDs and organic semiconductors delves into the applications of TMDO hybrid heterostructures. This review provides insights into the synthesis of 2D-TMDs and organic layers, covering fabrication techniques and challenges. Band bending and charge transfer via band energy alignment are explored from both structural and molecular orbital perspectives. The progress in emission modulation, including charge transfer, energy transfer, doping, defect healing, and phase engineering, is presented. The recent advancements in 2D-TMDO-based optoelectronic synaptic devices, including various 2D-TMDs and organic materials for neuromorphic applications are discussed. The section assesses their compatibility for synaptic devices, revisits the operating principles, and highlights the recent device demonstrations. Existing challenges and potential solutions are discussed. Finally, the review concludes by outlining the current challenges that span from synthesis intricacies to device applications, and by offering an outlook on the evolving field of emerging TMDO heterostructures.
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Affiliation(s)
- Sk Md Obaidulla
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička Cesta 46, HR-10000 Zagreb, Croatia.
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Sector III, Block JD, Salt Lake, Kolkata 700106, India
| | - Antonio Supina
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička Cesta 46, HR-10000 Zagreb, Croatia.
- Chair of Physics, Montanuniversität Leoben, Franz Josef Strasse 18, 8700 Leoben, Austria
| | - Sherif Kamal
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička Cesta 46, HR-10000 Zagreb, Croatia.
| | - Yahya Khan
- Department of Physics, Karakoram International university (KIU), Gilgit 15100, Pakistan
| | - Marko Kralj
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička Cesta 46, HR-10000 Zagreb, Croatia.
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16
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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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17
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Zhao H, Zhu L, Li X, Chandrasekaran V, Baldwin JK, Pettes MT, Piryatinski A, Yang L, Htoon H. Manipulating Interlayer Excitons for Near-Infrared Quantum Light Generation. NANO LETTERS 2023. [PMID: 38038967 DOI: 10.1021/acs.nanolett.3c03296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Interlayer excitons (IXs) formed at the interface of van der Waals materials possess various novel properties. In parallel development, strain engineering has emerged as an effective means for creating 2D quantum emitters. Exploring the intersection of these two exciting areas, we use MoS2/WSe2 heterostructure as a model system and demonstrate how strain, defects, and layering can be utilized to create defect-bound IXs capable of bright, robust, and tunable quantum light emission in the technologically important near-infrared spectral range. Our work presents defect-bound IXs as a promising platform for pushing the performance of 2D quantum emitters beyond their current limitations.
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Affiliation(s)
- Huan Zhao
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Linghan Zhu
- Department of Physics, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Xiangzhi Li
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Vigneshwaran Chandrasekaran
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Jon Kevin Baldwin
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Michael T Pettes
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Andrei Piryatinski
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Li Yang
- Department of Physics, Washington University in St. Louis, St. Louis, Missouri 63130, United States
- Institute of Materials Science and Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Han Htoon
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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18
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Jiang W, Sofer R, Gao X, Tkatchenko A, Kronik L, Ouyang W, Urbakh M, Hod O. Anisotropic Interlayer Force Field for Group-VI Transition Metal Dichalcogenides. J Phys Chem A 2023; 127:9820-9830. [PMID: 37938019 DOI: 10.1021/acs.jpca.3c04540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
An anisotropic interlayer force field that describes the interlayer interactions in homogeneous and heterogeneous interfaces of group-VI transition metal dichalcogenides (MX2, where M = Mo, W, and X = S, Se) is presented. The force field is benchmarked against density functional theory calculations for bilayer systems within the Heyd-Scuseria-Ernzerhof hybrid density functional approximation, augmented by a nonlocal many-body dispersion treatment of long-range correlation. The parametrization yields good agreement with the reference calculations of binding energy curves and sliding potential energy surfaces. It is found to be transferable to transition metal dichalcogenide (TMD) junctions outside of the training set that contain the same atom types. Calculated bulk moduli agree with most previous dispersion-corrected density functional theory predictions, which underestimate the available experimental values. Calculated phonon spectra of the various junctions under consideration demonstrate the importance of appropriately treating the anisotropic nature of the layered interfaces. Considering our previous parametrization for MoS2, the anisotropic interlayer potential enables accurate and efficient large-scale simulations of the dynamical, tribological, and thermal transport properties of a large set of homogeneous and heterogeneous TMD interfaces.
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Affiliation(s)
- Wenwu Jiang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China
| | - Reut Sofer
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Xiang Gao
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Alexandre Tkatchenko
- Department of Physics and Materials Science, University of Luxembourg, L-1511 Luxembourg City, Luxembourg
| | - Leeor Kronik
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovoth 76100, Israel
| | - Wengen Ouyang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China
- State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China
| | - Michael Urbakh
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Oded Hod
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
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19
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Konthoujam JS, Lin YS, Chang YH, Lin HT, Chang CY, Zhang YW, Lin SY, Kuo HC, Shih MH. Dynamical characteristics of AC-driven hybrid WSe 2 monolayer/AlGaInP quantum wells light-emitting device. DISCOVER NANO 2023; 18:140. [PMID: 37943364 PMCID: PMC10635932 DOI: 10.1186/s11671-023-03920-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 10/30/2023] [Indexed: 11/10/2023]
Abstract
The exploration of functional light-emitting devices and numerous optoelectronic applications can be accomplished on an elegant platform provided by rapidly developing transition metal dichalcogenides (TMDCs). However, TMDCs-based light emitting devices encounter certain serious difficulties, such as high resistance losses from ohmic contacts or the need for complex heterostructures, which restricts the device applications. Despite the fact that AC-driven light emitting devices have developed ways to overcome these challenges, there is still a significant demand for multiple wavelength emission from a single device, which is necessary for full color light emitting devices. Here, we developed a dual-color AC-driven light-emitting device by integrating the WSe2 monolayer and AlGaInP-GaInP multiple quantum well (MQW) structures in the form of capacitor structure using AlOx insulating layer between the two emitters. In order to comprehend the characteristics of the hybrid device under various driving circumstances, we investigate the frequency-dependent EL intensity of the hybrid device using an equivalent RC circuit model. The time-resolved electroluminescence (TREL) characteristics of the hybrid device were analyzed in details to elucidate the underlying physical mechanisms governing its performance under varying applied frequencies. This dual-color hybrid light-emitting device enables the use of 2-D TMDC-based light emitters in a wider range of applications, including broad-band LEDs, quantum display systems, and chip-scale optoelectronic integrated systems.
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Affiliation(s)
| | - Yen-Shou Lin
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei, 11529, Taiwan
- Department of Photonics and Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Ya-Hui Chang
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei, 11529, Taiwan
- Department of Photonics and Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Hsiang-Ting Lin
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei, 11529, Taiwan
| | - Chiao-Yun Chang
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei, 11529, Taiwan
| | - Yu-Wei Zhang
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei, 11529, Taiwan
- Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Shih-Yen Lin
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei, 11529, Taiwan
- Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Hao-Chung Kuo
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei, 11529, Taiwan
- Department of Photonics and Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Min-Hsiung Shih
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei, 11529, Taiwan.
- Department of Photonics and Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan.
- Department of Photonics, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan.
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20
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Lee SH, Kim TJ, Lee E, Kwon D, Kim J, Joo J. Observation of aligned dipoles and angular chromism of exciplexes in organic molecular heterostructures. Nat Commun 2023; 14:7190. [PMID: 37938244 PMCID: PMC10632441 DOI: 10.1038/s41467-023-42976-y] [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: 05/09/2023] [Accepted: 10/26/2023] [Indexed: 11/09/2023] Open
Abstract
The dipole characteristics of Frenkel excitons and charge-transfer excitons between donor and acceptor molecules in organic heterostructures such as exciplexes are important in organic photonics and optoelectronics. For the bilayer of the organic donor 4,4',4''-tris[(3-methylphenyl)phenylamino]triphenylamine and acceptor 2,4,6-tris(biphenyl-3-yl)-1,3,5-triazine molecules, the exciplexes form aligned dipoles perpendicular to the Frenkel excitons, as observed in back focal plane photoluminescence images. The angular chromism of exciplexes observed in the 100 meV range indicates possible delocalization and angle-sensing photonic applications. The blue shift of the peak position and increase in the linewidth of photoluminescene spectra with increasing excitation power are caused by the repulsive aligned exciplex dipole moments with a long lifetime (4.65 μs). Electroluminescence spectra of the exciplex from organic light-emitting diodes using the bilayer are blue-shifted with increasing bias, suggesting unidirectional alignment of the exciplex dipole moments. The observation of exciplex dipole moment alignments across molecular interfaces can facilitate the controlled coupling of exciton species and increase efficiency of organic light-emitting diodes.
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Affiliation(s)
- Sang-Hun Lee
- Department of Physics, Korea University, Seoul, 02841, Republic of Korea
| | - Taek Joon Kim
- Department of Physics, Korea University, Seoul, 02841, Republic of Korea
| | - Eunji Lee
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Dayeong Kwon
- Department of Physics, Korea University, Seoul, 02841, Republic of Korea
| | - Jeongyong Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
| | - Jinsoo Joo
- Department of Physics, Korea University, Seoul, 02841, Republic of Korea.
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21
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Yu L, Pistunova K, Hu J, Watanabe K, Taniguchi T, Heinz TF. Observation of quadrupolar and dipolar excitons in a semiconductor heterotrilayer. NATURE MATERIALS 2023:10.1038/s41563-023-01678-y. [PMID: 37857888 DOI: 10.1038/s41563-023-01678-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 09/06/2023] [Indexed: 10/21/2023]
Abstract
Van der Waals (vdW) materials have opened up many avenues for discovery through layer assembly, as epitomized by interlayer dipolar excitons that exhibit electrically tunable luminescence, lasing and exciton condensation. Extending interlayer excitons to more vdW layers, however, raises fundamental questions concerning coherence within excitons and coupling between moiré superlattices at multiple interfaces. Here, by assembling angle-aligned WSe2/WS2/WSe2 heterotrilayers, we demonstrate the emergence of quadrupolar excitons. We confirm the exciton's quadrupolar nature by the decrease in its energy of 12 meV from coherent hole tunnelling between the two outer layers, its tunable static dipole moment under an external electric field and the reduced exciton-exciton interactions. At high exciton density, we also see signatures of a phase of oppositely aligned dipolar excitons, consistent with a staggered dipolar phase predicted to be driven by attractive dipolar interactions. Our demonstration paves the way for discovering emergent exciton orderings for three vdW layers and beyond.
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Affiliation(s)
- Leo Yu
- E. L. Ginzton Laboratory, Stanford University, Stanford, CA, USA.
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA.
| | - Kateryna Pistunova
- E. L. Ginzton Laboratory, Stanford University, Stanford, CA, USA
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Jenny Hu
- E. L. Ginzton Laboratory, Stanford University, Stanford, CA, 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
| | - Tony F Heinz
- E. L. Ginzton Laboratory, Stanford University, Stanford, CA, USA.
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA.
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22
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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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23
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Pimenta Martins LG, Ruiz-Tijerina DA, Occhialini CA, Park JH, Song Q, Lu AY, Venezuela P, Cançado LG, Mazzoni MSC, Matos MJS, Kong J, Comin R. Pressure tuning of minibands in MoS 2/WSe 2 heterostructures revealed by moiré phonons. NATURE NANOTECHNOLOGY 2023; 18:1147-1153. [PMID: 37322144 DOI: 10.1038/s41565-023-01413-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 05/08/2023] [Indexed: 06/17/2023]
Abstract
Moiré superlattices of two-dimensional heterostructures arose as a new platform to investigate emergent behaviour in quantum solids with unprecedented tunability. To glean insights into the physics of these systems, it is paramount to discover new probes of the moiré potential and moiré minibands, as well as their dependence on external tuning parameters. Hydrostatic pressure is a powerful control parameter, since it allows to continuously and reversibly enhance the moiré potential. Here we use high pressure to tune the minibands in a rotationally aligned MoS2/WSe2 moiré heterostructure, and show that their evolution can be probed via moiré phonons. The latter are Raman-inactive phonons from the individual layers that are activated by the moiré potential. Moiré phonons manifest themselves as satellite Raman peaks arising exclusively from the heterostructure region, increasing in intensity and frequency under applied pressure. Further theoretical analysis reveals that their scattering rate is directly connected to the moiré potential strength. By comparing the experimental and calculated pressure-induced enhancement, we obtain numerical estimates for the moiré potential amplitude and its pressure dependence. The present work establishes moiré phonons as a sensitive probe of the moiré potential as well as the electronic structures of moiré systems.
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Affiliation(s)
| | - David A Ruiz-Tijerina
- Departamento de Física Química, Instituto de Física, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Connor A Occhialini
- Physics Department, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ji-Hoon Park
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Qian Song
- Physics Department, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ang-Yu Lu
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Pedro Venezuela
- Instituto de Física, Universidade Federal Fluminense, Niterói, Brazil
| | - Luiz G Cançado
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Mário S C Mazzoni
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Matheus J S Matos
- Departamento de Física, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
| | - Jing Kong
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Riccardo Comin
- Physics Department, Massachusetts Institute of Technology, Cambridge, MA, USA.
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24
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Conti S, Chaves A, Pandey T, Covaci L, Peeters FM, Neilson D, Milošević MV. Flattening conduction and valence bands for interlayer excitons in a moiré MoS 2/WSe 2 heterobilayer. NANOSCALE 2023; 15:14032-14042. [PMID: 37575033 DOI: 10.1039/d3nr01183f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
We explore the flatness of conduction and valence bands of interlayer excitons in MoS2/WSe2 van der Waals heterobilayers, tuned by interlayer twist angle, pressure, and external electric field. We employ an efficient continuum model where the moiré pattern from lattice mismatch and/or twisting is represented by an equivalent mesoscopic periodic potential. We demonstrate that the mismatch moiré potential is too weak to produce significant flattening. Moreover, we draw attention to the fact that the quasi-particle effective masses around the Γ-point and the band flattening are reduced with twisting. As an alternative approach, we show (i) that reducing the interlayer distance by uniform vertical pressure can significantly increase the effective mass of the moiré hole, and (ii) that the moiré depth and its band flattening effects are strongly enhanced by accessible electric gating fields perpendicular to the heterobilayer, with resulting electron and hole effective masses increased by more than an order of magnitude - leading to record-flat bands. These findings impose boundaries on the commonly generalized benefits of moiré twistronics, while also revealing alternative feasible routes to achieve truly flat electron and hole bands to carry us to strongly correlated excitonic phenomena on demand.
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Affiliation(s)
- Sara Conti
- Department of Physics, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
| | - Andrey Chaves
- Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, Fortaleza 60455-760, Brazil
| | - Tribhuwan Pandey
- Department of Physics, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
| | - Lucian Covaci
- Department of Physics, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
- NANOlab Center of Excellence, University of Antwerp, Antwerp 2020, Belgium
| | - François M Peeters
- Department of Physics, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
- Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, Fortaleza 60455-760, Brazil
| | - David Neilson
- Department of Physics, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
| | - Milorad V Milošević
- Department of Physics, University of Antwerp, Groenenborgerlaan 171, Antwerp 2020, Belgium.
- NANOlab Center of Excellence, University of Antwerp, Antwerp 2020, Belgium
- Instituto de Física, Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso 78060-900, Brazil
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25
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Montblanch ARP, Barbone M, Aharonovich I, Atatüre M, Ferrari AC. Layered materials as a platform for quantum technologies. NATURE NANOTECHNOLOGY 2023:10.1038/s41565-023-01354-x. [PMID: 37322143 DOI: 10.1038/s41565-023-01354-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 02/17/2023] [Indexed: 06/17/2023]
Abstract
Layered materials are taking centre stage in the ever-increasing research effort to develop material platforms for quantum technologies. We are at the dawn of the era of layered quantum materials. Their optical, electronic, magnetic, thermal and mechanical properties make them attractive for most aspects of this global pursuit. Layered materials have already shown potential as scalable components, including quantum light sources, photon detectors and nanoscale sensors, and have enabled research of new phases of matter within the broader field of quantum simulations. In this Review we discuss opportunities and challenges faced by layered materials within the landscape of material platforms for quantum technologies. In particular, we focus on applications that rely on light-matter interfaces.
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Affiliation(s)
- Alejandro R-P Montblanch
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Matteo Barbone
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Cambridge Graphene Centre, University of Cambridge, Cambridge, UK
- Munich Center for Quantum Science and Technology, (MCQST), Munich, Germany
- Walter Schottky Institut and Department of Electrical and Computer Engineering, Technische Universität München, Garching, Germany
| | - Igor Aharonovich
- School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, New South Wales, Sydney, Australia
- Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems, University of Technology Sydney, Ultimo, New South Wales, Sydney, Australia
| | - Mete Atatüre
- Cavendish Laboratory, University of Cambridge, Cambridge, UK.
| | - Andrea C Ferrari
- Cambridge Graphene Centre, University of Cambridge, Cambridge, UK.
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26
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Khelifa R, Shan S, Moilanen AJ, Taniguchi T, Watanabe K, Novotny L. WSe 2 Light-Emitting Device Coupled to an h-BN Waveguide. ACS PHOTONICS 2023; 10:1328-1333. [PMID: 37215323 PMCID: PMC10197165 DOI: 10.1021/acsphotonics.2c01963] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Indexed: 05/24/2023]
Abstract
Optical information processing using photonic integrated circuits is a key goal in the field of nanophotonics. Extensive research efforts have led to remarkable progress in integrating active and passive device functionalities within one single photonic circuit. Still, to date, one of the central components, i.e., light sources, remain a challenge to be integrated. Here, we focus on a photonic platform that is solely based on two-dimensional materials to enable the integration of electrically contacted optoelectronic devices inside the light-confining dielectric of photonic structures. We combine light-emitting devices, based on exciton recombination in transition metal dichalcogenides, with hexagonal boron nitride photonic waveguides in a single van der Waals heterostructure. Waveguide-coupled light emission is achieved by sandwiching the light-emitting device between two hexagonal boron nitride slabs and patterning the complete van der Waals stack into a photonic structure. Our demonstration of on-chip light generation and waveguiding is a key component for future integrated van der Waals optoelectronics.
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Affiliation(s)
- Ronja Khelifa
- Photonics
Laboratory, ETH Zürich, 8093 Zürich, Switzerland
| | - Shengyu Shan
- Photonics
Laboratory, ETH Zürich, 8093 Zürich, Switzerland
| | | | - Takashi Taniguchi
- International
Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Kenji Watanabe
- Research
Center for Functional Materials, National
Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Lukas Novotny
- Photonics
Laboratory, ETH Zürich, 8093 Zürich, Switzerland
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27
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Kim TJ, Lee S, Lee E, Seo C, Kim J, Joo J. Far-Red Interlayer Excitons of Perovskite/Quantum-Dot Heterostructures. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207653. [PMID: 36938849 PMCID: PMC10190583 DOI: 10.1002/advs.202207653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 02/16/2023] [Indexed: 05/18/2023]
Abstract
Interlayer excitons (IXs) at the interface of heterostructures (HSs) with a staggered band alignment are fascinating quantum quasi-particles with light-emitting and long-lifetime characteristics. In this study, the energy band alignments (EBAs) of the HS of MAPbI3 perovskite thin sheets with CdSe-ZnS core-shell quantum dot (QD) layers are modulated by using different diameters of the QDs. Far-red IX emission is observed at 1.42 eV from the HS of MAPbI3 /CdSe-ZnS-QD (λem = 645 nm) with type-II EBA owing to charge transfer. The lifetime of the far-red IXs is estimated to be 5.68 µs, which is considerably longer than that (0.715 ns) of the intralayer excitons from CdSe-ZnS-QD. With increasing incident excitation power, the PL peak and its intensity of IXs are blue-shifted and linearly increased, respectively, indicating a strong dipole alignment of far-red IXs at the heterojunction. Back focal plane imaging suggests that the directions of dipole moments of the IXs are relatively out-of-plane compared to those of the intralayer excitons (MAPbI3 and CdSe-ZnS-QD). Notably, the abnormal behavior of the optical characteristics is observed near the phase transition temperature (90 K) of MAPbI3 . MAPbI3 /CdSe-ZnS-QD HS photodetectors show the increase in photocurrent and detectivity compared to MAPbI3 at IX excitation.
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Affiliation(s)
- Taek Joon Kim
- Department of PhysicsKorea UniversitySeoul02841Republic of Korea
| | - Sang‐hun Lee
- Department of PhysicsKorea UniversitySeoul02841Republic of Korea
| | - Eunji Lee
- Department of Energy ScienceSungkyunkwan UniversitySuwon16419Republic of Korea
| | - Changwon Seo
- Department of Energy ScienceSungkyunkwan UniversitySuwon16419Republic of Korea
- Department of Physics and Energy Harvest‐Storage Research CenterUniversity of UlsanUlsan44610Republic of Korea
| | - Jeongyong Kim
- Department of Energy ScienceSungkyunkwan UniversitySuwon16419Republic of Korea
| | - Jinsoo Joo
- Department of PhysicsKorea UniversitySeoul02841Republic of Korea
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28
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Tan Q, Rasmita A, Zhang Z, Cai H, Cai X, Dai X, Watanabe K, Taniguchi T, MacDonald AH, Gao W. Layer-dependent correlated phases in WSe 2/MoS 2 moiré superlattice. NATURE MATERIALS 2023; 22:605-611. [PMID: 37069294 DOI: 10.1038/s41563-023-01521-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 02/28/2023] [Indexed: 05/05/2023]
Abstract
Electron correlation plays an essential role in the macroscopic quantum phenomena in the moiré heterostructure, such as antiferromagnetism and correlated insulating phases. Unlike the phenomena where the interaction involves only electrons in one layer, the interaction of distinct phases in two or more layers represents a new horizon forward, such as the one in the Kondo lattice model. Here, using interlayer excitons as a probe, we show that the interlayer interactions in heterobilayers of tungsten diselenide and molybdenum disulfide (WSe2/MoS2) can be electrically switched on and off, resulting in a layer-dependent correlated phase diagram, including single-layer, layer-selective, excitonic-insulator and layer-hybridized regions. We demonstrate that these correlated phases affect the interlayer exciton non-radiative decay pathways. These results reveal the role of strong correlation on interlayer exciton dynamics and pave the way for studying the layer-resolved strong correlation behaviour in moiré heterostructures.
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Affiliation(s)
- Qinghai Tan
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
- The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore, Singapore
| | - Abdullah Rasmita
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Zhaowei Zhang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Hongbing Cai
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
- The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore, Singapore
| | - Xiangbin Cai
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Xuran Dai
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Allan H MacDonald
- Department of Physics, The University of Texas at Austin, Austin, TX, USA.
| | - Weibo Gao
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore.
- The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore, Singapore.
- Centre for Quantum Technologies, National University of Singapore, Singapore, Singapore.
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29
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Elbanna A, Jiang H, Fu Q, Zhu JF, Liu Y, Zhao M, Liu D, Lai S, Chua XW, Pan J, Shen ZX, Wu L, Liu Z, Qiu CW, Teng J. 2D Material Infrared Photonics and Plasmonics. ACS NANO 2023; 17:4134-4179. [PMID: 36821785 DOI: 10.1021/acsnano.2c10705] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Two-dimensional (2D) materials including graphene, transition metal dichalcogenides, black phosphorus, MXenes, and semimetals have attracted extensive and widespread interest over the past years for their many intriguing properties and phenomena, underlying physics, and great potential for applications. The vast library of 2D materials and their heterostructures provides a diverse range of electrical, photonic, mechanical, and chemical properties with boundless opportunities for photonics and plasmonic devices. The infrared (IR) regime, with wavelengths across 0.78 μm to 1000 μm, has particular technological significance in industrial, military, commercial, and medical settings while facing challenges especially in the limit of materials. Here, we present a comprehensive review of the varied approaches taken to leverage the properties of the 2D materials for IR applications in photodetection and sensing, light emission and modulation, surface plasmon and phonon polaritons, non-linear optics, and Smith-Purcell radiation, among others. The strategies examined include the growth and processing of 2D materials, the use of various 2D materials like semiconductors, semimetals, Weyl-semimetals and 2D heterostructures or mixed-dimensional hybrid structures, and the engineering of light-matter interactions through nanophotonics, metasurfaces, and 2D polaritons. Finally, we give an outlook on the challenges in realizing high-performance and ambient-stable devices and the prospects for future research and large-scale commercial applications.
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Affiliation(s)
- Ahmed Elbanna
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, Singapore 637371, Singapore
| | - Hao Jiang
- Department of Electrical and Electronic Engineering, National University of Singapore, Singapore 117583, Singapore
| | - Qundong Fu
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- CINTRA CNRS/NTU/THALES, UMI 3288, Research Techno Plaza, Singapore 637553, Singapore
| | - Juan-Feng Zhu
- Science, Mathematics and Technology (SMT), Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore
| | - Yuanda Liu
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Meng Zhao
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Dongjue Liu
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Samuel Lai
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Xian Wei Chua
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Jisheng Pan
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Ze Xiang Shen
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, Singapore 637371, Singapore
- Interdisciplinary Graduate Program, Energy Research Institute@NTU, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- The Photonics Institute and Center for Disruptive Photonic Technologies, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 Singapore
| | - Lin Wu
- Science, Mathematics and Technology (SMT), Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore
- Institute of High Performance Computing, Agency for Science Technology and Research (A*STAR), 1 Fusionopolis Way, Singapore 138632, Singapore
| | - Zheng Liu
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- CINTRA CNRS/NTU/THALES, UMI 3288, Research Techno Plaza, Singapore 637553, Singapore
| | - Cheng-Wei Qiu
- Department of Electrical and Electronic Engineering, National University of Singapore, Singapore 117583, Singapore
| | - Jinghua Teng
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
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30
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Xiao C, Wang Y, Yao W. Dynamic Generation of Spin Spirals of Moiré Trapped Carriers via Exciton Mediated Spin Interactions. NANO LETTERS 2023; 23:1872-1877. [PMID: 36799955 DOI: 10.1021/acs.nanolett.2c04816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Stacking transition metal dichalcogenides (TMDs) to form moiré superlattices has provided exciting opportunities to explore many-body correlation phenomena of the moiré trapped carriers. TMD bilayers, on the other hand, host long-lived interlayer exciton (IX), an elementary excitation of long spin-valley lifetime that can be optically or electrically injected. Here we find that, through the Coulomb exchange between mobile IXs and carriers, the IX bath can mediate both Heisenberg and Dzyaloshinskii-Moriya type spin interactions between moiré trapped carriers, controllable by exciton density and exciton spin current, respectively. We show the strong Heisenberg interaction and the extraordinarily long-ranged Dzyaloshinskii-Moriya interaction here can jointly establish robust spin spiral magnetic orders in Mott-Wigner crystal states at various filling factors, with the spiral direction controlled by the exciton current.
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Affiliation(s)
- Chengxin Xiao
- Department of Physics, The University of Hong Kong, Hong Kong, China
- HKU-UCAS Joint Institute of Theoretical and Computational Physics at Hong Kong, Hong Kong, China
| | - Yong Wang
- School of Physics, Nankai University, Tianjin 300071, China
- Department of Physics, The University of Hong Kong, Hong Kong, Hong Kong, China
| | - Wang Yao
- Department of Physics, The University of Hong Kong, Hong Kong, China
- HKU-UCAS Joint Institute of Theoretical and Computational Physics at Hong Kong, Hong Kong, China
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31
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Chang YH, Lin YS, James Singh K, Lin HT, Chang CY, Chen ZZ, Zhang YW, Lin SY, Kuo HC, Shih MH. AC-driven multicolor electroluminescence from a hybrid WSe 2 monolayer/AlGaInP quantum well light-emitting device. NANOSCALE 2023; 15:1347-1356. [PMID: 36562246 DOI: 10.1039/d2nr03725d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Light-emitting diodes (LEDs) are used widely, but when operated at a low-voltage direct current (DC), they consume unnecessary power because a converter must be used to convert it to an alternating current (AC). DC flow across devices also causes charge accumulation at a high current density, leading to lowered LED reliability. In contrast, gallium-nitride-based LEDs can be operated without an AC-DC converter being required, potentially leading to greater energy efficiency and reliability. In this study, we developed a multicolor AC-driven light-emitting device by integrating a WSe2 monolayer and AlGaInP-GaInP multiple quantum well (MQW) structures. The CVD-grown WSe2 monolayer was placed on the top of an AlGaInP-based light-emitting diode (LED) wafer to create a two-dimensional/three-dimensional heterostructure. The interfaces of these hybrid devices are characterized and verified through transmission electron microscopy and energy-dispersive X-ray spectroscopy techniques. More than 20% energy conversion from the AlGaInP MQWs to the WSe2 monolayer was observed to boost the WSe2 monolayer emissions. The voltage dependence of the electroluminescence intensity was characterized. Electroluminescence intensity-voltage characteristic curves indicated that thermionic emission was the mechanism underlying carrier injection across the potential barrier at the Ag-WSe2 monolayer interface at low voltage, whereas Fowler-Nordheim emission was the mechanism at voltages higher than approximately 8.0 V. These multi-color hybrid light-emitting devices both expand the wavelength range of 2-D TMDC-based light emitters and support their implementation in applications such as chip-scale optoelectronic integrated systems, broad-band LEDs, and quantum display systems.
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Affiliation(s)
- Ya-Hui Chang
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei 11529, Taiwan.
- Department of Photonics and Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Yen-Shou Lin
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei 11529, Taiwan.
- Department of Photonics and Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Konthoujam James Singh
- Department of Photonics and Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Hsiang-Ting Lin
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei 11529, Taiwan.
| | - Chiao-Yun Chang
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei 11529, Taiwan.
- Department of Electrical Engineering, National Taiwan Ocean University, Keelung 202301, Taiwan
| | - Zheng-Zhe Chen
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei 11529, Taiwan.
- Department of Physics, National Taiwan University, Taipei, Taiwan, Taipei 10617, Taiwan
| | - Yu-Wei Zhang
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei 11529, Taiwan.
- Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Shih-Yen Lin
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei 11529, Taiwan.
- Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Hao-Chung Kuo
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei 11529, Taiwan.
- Department of Photonics and Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Min-Hsiung Shih
- Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei 11529, Taiwan.
- Department of Photonics and Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
- Department of Photonics, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
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32
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Tan Q, Rasmita A, Zhang Z, Novoselov KS, Gao WB. Signature of Cascade Transitions between Interlayer Excitons in a Moiré Superlattice. PHYSICAL REVIEW LETTERS 2022; 129:247401. [PMID: 36563256 DOI: 10.1103/physrevlett.129.247401] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Accepted: 11/08/2022] [Indexed: 06/17/2023]
Abstract
A moiré superlattice in transition metal dichalcogenides heterostructure provides an exciting platform for studying strongly correlated electronics and excitonic physics, such as multiple interlayer exciton (IX) energy bands. However, the correlations between these IXs remain elusive. Here, we demonstrate the cascade transitions between IXs in a moiré superlattice by performing energy- and time-resolved photoluminescence measurements in the MoS_{2}/WSe_{2} heterostructure. Furthermore, we show that the lower-energy IX can be excited to higher-energy ones, facilitating IX population inversion. Our finding of cascade transitions between IXs contributes to the fundamental understanding of the IX dynamics in moiré superlattices and may have important applications, such as in exciton condensate, quantum information protocols, and quantum cascade lasers.
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Affiliation(s)
- 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
| | - Abdullah Rasmita
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Zhaowei Zhang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - K S Novoselov
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575, Singapore
| | - Wei-Bo 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
- Centre for Quantum Technologies, National University of Singapore, 117543 Singapore, Singapore
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33
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Generating intense electric fields in 2D materials by dual ionic gating. Nat Commun 2022; 13:6601. [PMID: 36329011 PMCID: PMC9633598 DOI: 10.1038/s41467-022-34158-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 10/14/2022] [Indexed: 11/06/2022] Open
Abstract
The application of an electric field through two-dimensional materials (2DMs) modifies their properties. For example, a bandgap opens in semimetallic bilayer graphene while the bandgap shrinks in few-layer 2D semiconductors. The maximum electric field strength achievable in conventional devices is limited to ≤0.3 V/nm by the dielectric breakdown of gate dielectrics. Here, we overcome this limit by suspending a 2DM between two volumes of ionic liquid (IL) with independently controlled potentials. The potential difference between the ILs falls across an ultrathin layer consisting of the 2DM and the electrical double layers above and below it, producing an intense electric field larger than 4 V/nm. This field is strong enough to close the bandgap of few-layer WSe2, thereby driving a semiconductor-to-metal transition. The ability to apply fields an order of magnitude higher than what is possible in dielectric-gated devices grants access to previously-inaccessible phenomena occurring in intense electric fields. The application of electric fields >1 V/nm in solid state devices could provide access to unexplored phenomena, but it is currently difficult to implement. Here, the authors develop a double-sided ionic liquid gating technique to generate electric fields as large as 4 V/nm across few-layer WSe2, leading to field-induced semiconductor-to-metal transitions.
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34
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Ma EY, Hu J, Waldecker L, Watanabe K, Taniguchi T, Liu F, Heinz TF. The Reststrahlen Effect in the Optically Thin Limit: A Framework for Resonant Response in Thin Media. NANO LETTERS 2022; 22:8389-8393. [PMID: 36112673 DOI: 10.1021/acs.nanolett.2c02819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Sharp resonances can strongly modify the electromagnetic response of matter. A classic example is the Reststrahlen effect - high reflectivity in the mid-infrared in many polar crystals near their optical phonon resonances. Although this effect in bulk materials has been studied extensively, a systematic treatment for finite thickness remains challenging. Here we describe, experimentally and theoretically, the Reststrahlen response in hexagonal boron nitride across more than 5 orders of magnitude in thickness, down to a monolayer. We find that the high reflectivity plateau of the Reststrahlen band evolves into a single peak as the material enters the optically thin limit, within which two distinct regimes emerge: a strong-response regime dominated by coherent radiative decay and a weak-response regime dominated by damping. We show that this evolution can be explained by a simple two-dimensional sheet model that can be applied to a wide range of thin media.
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Affiliation(s)
- Eric Y Ma
- Department of Applied Physics, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- Department of Physics, University of California, Berkeley, Berkeley, California 94720, United States
| | - Jenny Hu
- Department of Applied Physics, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Lutz Waldecker
- Department of Applied Physics, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, 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
| | - Fang Liu
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Tony F Heinz
- Department of Applied Physics, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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35
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Shinokita K, Watanabe K, Taniguchi T, Matsuda K. Valley Relaxation of the Moiré Excitons in a WSe 2/MoSe 2 Heterobilayer. ACS NANO 2022; 16:16862-16868. [PMID: 36169188 DOI: 10.1021/acsnano.2c06813] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The moiré superlattice consisting of lattice- or angular-mismatched van der Waals heterostructures drastically changes the physical properties of constituent atomically thin materials by confinement of the exciton by the moiré potential, which is promising for next-generation quantum optics. The moiré superlattice also affects the valley degrees of freedom of the monolayer transition-metal dichalcogenides (TMDs) and the valley-dependent optical selection rule, which results in the characteristic circular polarized light emission of the moiré exciton. However, the valley relaxation process of excitons in the moiré superlattice remains to be understood. Here, we studied valley relaxation of moiré excitons in a twisted WSe2/MoSe2 heterobilayer by circularly polarized photoluminescence and photoluminescence excitation (PLE) spectroscopy. The experimentally observed circularly polarized emission strongly depends on the excitation power density, which contrasts with the case of two-dimensional monolayer TMDs. The excitation power-dependent circularly polarized emission suggests the characteristic valley relaxation of the moiré exciton with a small density of states in zero-dimensional systems. In addition, the resonant PLE measurement reveals the intravalley relaxation process from the triplet to singlet state of the moiré exciton via Γ5 phonon emission. Our findings clarified the valley relaxation of the moiré excitons, which would lead to the application of the circularly polarized quantum light emitter in twisted semiconducting heterobilayers.
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Affiliation(s)
- Keisuke Shinokita
- Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Kazunari Matsuda
- Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan
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36
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Zhang L, Jiang J, Hu Y, Lu Z, Wen X, Pendse S, Jia R, Wang GC, Lu TM, Shi J. Liquid-Phase van der Waals Epitaxy of a Few-Layer and Unit-Cell Thick Ruddlesden-Popper Halide Perovskite. J Am Chem Soc 2022; 144:17588-17596. [PMID: 36099192 DOI: 10.1021/jacs.2c07069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
2D Ruddlesden-Popper (RP) halide perovskites with natural multiple quantum well structures are an ideal platform to integrate into vertical heterostructures, which may introduce plentiful intriguing optoelectronic properties that are not accessible in a single bulk crystal. Here, we report liquid-phase van der Waals epitaxy of a 2D RP hybrid perovskite (4,4-DFPD)2PbI4 (4,4-DFPD is 4,4-difluoropiperidinium) on muscovite mica and fabricate a series of perovskite-perovskite vertical heterostructures by integrating it with a second 2D RP perovskite R-NPB [NPB = 1-(1-naphthyl)ethylammonium lead bromide] sheets. The grown (4,4-DFPD)2PbI4 nanobelt array can be multiple layers to unit-cell thin and are crystallographically aligned on the mica substrate. An interlayer photo emission in this R-NPB/(4,4-DFPD)2PbI4 heterostructure with a lifetime of about 25 ns at 120 K has been revealed. Our demonstration of epitaxial (4,4-DFPD)2PbI4 array grown on mica via liquid-phase van der Waals epitaxy provides a paradigm to prepare orderly distributed 2D RP hybrid perovskites for further integration into multiple heterostructures. The discovery of a new interlayer emission in the R-NPB/(4,4-DFPD)2PbI4 heterostructure enriches the basic understanding of interlayer charge transition in halide perovskite systems.
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Affiliation(s)
- Lifu Zhang
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Jie Jiang
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Yang Hu
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Zonghuan Lu
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Xixing Wen
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Saloni Pendse
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Ru Jia
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Gwo-Ching Wang
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Toh-Ming Lu
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Jian Shi
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
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37
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Formation of moiré interlayer excitons in space and time. Nature 2022; 608:499-503. [PMID: 35978130 DOI: 10.1038/s41586-022-04977-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 06/14/2022] [Indexed: 11/09/2022]
Abstract
Moiré superlattices in atomically thin van der Waals heterostructures hold great promise for extended control of electronic and valleytronic lifetimes1-7, the confinement of excitons in artificial moiré lattices8-13 and the formation of exotic quantum phases14-18. Such moiré-induced emergent phenomena are particularly strong for interlayer excitons, where the hole and the electron are localized in different layers of the heterostructure19,20. To exploit the full potential of correlated moiré and exciton physics, a thorough understanding of the ultrafast interlayer exciton formation process and the real-space wavefunction confinement is indispensable. Here we show that femtosecond photoemission momentum microscopy provides quantitative access to these key properties of the moiré interlayer excitons. First, we elucidate that interlayer excitons are dominantly formed through femtosecond exciton-phonon scattering and subsequent charge transfer at the interlayer-hybridized Σ valleys. Second, we show that interlayer excitons exhibit a momentum fingerprint that is a direct hallmark of the superlattice moiré modification. Third, we reconstruct the wavefunction distribution of the electronic part of the exciton and compare the size with the real-space moiré superlattice. Our work provides direct access to interlayer exciton formation dynamics in space and time and reveals opportunities to study correlated moiré and exciton physics for the future realization of exotic quantum phases of matter.
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38
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Barati F, Arp TB, Su S, Lake RK, Aji V, van Grondelle R, Rudner MS, Song JCW, Gabor NM. Vibronic Exciton-Phonon States in Stack-Engineered van der Waals Heterojunction Photodiodes. NANO LETTERS 2022; 22:5751-5758. [PMID: 35787025 PMCID: PMC9335870 DOI: 10.1021/acs.nanolett.2c00944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Stack engineering, an atomic-scale metamaterial strategy, enables the design of optical and electronic properties in van der Waals heterostructure devices. Here we reveal the optoelectronic effects of stacking-induced strong coupling between atomic motion and interlayer excitons in WSe2/MoSe2 heterojunction photodiodes. To do so, we introduce the photocurrent spectroscopy of a stack-engineered photodiode as a sensitive technique for probing interlayer excitons, enabling access to vibronic states typically found only in molecule-like systems. The vibronic states in our stack are manifest as a palisade of pronounced periodic sidebands in the photocurrent spectrum in frequency windows close to the interlayer exciton resonances and can be shifted "on demand" through the application of a perpendicular electric field via a source-drain bias voltage. The observation of multiple well-resolved sidebands as well as their ability to be shifted by applied voltages vividly demonstrates the emergence of interlayer exciton vibronic structure in a stack-engineered optoelectronic device.
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Affiliation(s)
- Fatemeh Barati
- Laboratory
of Quantum Materials Optoelectronics, Department of Physics and Astronomy, and Laboratory for Terahertz
and Terascale Electronics (LATTE), Department of Electrical and Computer
Engineering, University of California—Riverside, Riverside, California 92521, United States
| | - Trevor B. Arp
- Laboratory
of Quantum Materials Optoelectronics, Department of Physics and Astronomy, and Laboratory for Terahertz
and Terascale Electronics (LATTE), Department of Electrical and Computer
Engineering, University of California—Riverside, Riverside, California 92521, United States
| | - Shanshan Su
- Laboratory
of Quantum Materials Optoelectronics, Department of Physics and Astronomy, and Laboratory for Terahertz
and Terascale Electronics (LATTE), Department of Electrical and Computer
Engineering, University of California—Riverside, Riverside, California 92521, United States
| | - Roger K. Lake
- Laboratory
of Quantum Materials Optoelectronics, Department of Physics and Astronomy, and Laboratory for Terahertz
and Terascale Electronics (LATTE), Department of Electrical and Computer
Engineering, University of California—Riverside, Riverside, California 92521, United States
| | - Vivek Aji
- Laboratory
of Quantum Materials Optoelectronics, Department of Physics and Astronomy, and Laboratory for Terahertz
and Terascale Electronics (LATTE), Department of Electrical and Computer
Engineering, University of California—Riverside, Riverside, California 92521, United States
| | - Rienk van Grondelle
- Department
of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
- Canadian
Institute for Advanced Research, MaRS Centre
West Tower, 661 University
Avenue, Toronto, Ontario ON M5G 1M1, Canada
| | - Mark S. Rudner
- Department
of Physics, University of Washington, Seattle, Washington 98195, United States
- Niels
Bohr Institute, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Justin C. W. Song
- Division
of Physics and Applied Physics, School of Physical and Mathematical
Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Nathaniel M. Gabor
- Laboratory
of Quantum Materials Optoelectronics, Department of Physics and Astronomy, and Laboratory for Terahertz
and Terascale Electronics (LATTE), Department of Electrical and Computer
Engineering, University of California—Riverside, Riverside, California 92521, United States
- Canadian
Institute for Advanced Research, MaRS Centre
West Tower, 661 University
Avenue, Toronto, Ontario ON M5G 1M1, Canada
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39
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Dalla Valle P, Cavassilas N. A van der Waals heterojunction based on monolayers of MoS 2 and WSe 2 for overall solar water splitting. NANOSCALE ADVANCES 2022; 4:2816-2822. [PMID: 36132002 PMCID: PMC9417448 DOI: 10.1039/d2na00178k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 04/29/2022] [Indexed: 06/15/2023]
Abstract
Solar water splitting (SWS) has been widely studied as a promising technology for generating carbon-free hydrogen. In this article, we propose an unassisted SWS system based on van der Waals heterojunctions using monolayers of transition metal dichalcogenides as active core materials. This architecture, with its small band gap materials and high surface/volume ratio, has an intrinsic type-II band alignment that offers many advantages, such as direct Z-scheme configuration and wide absorption. To estimate the solar-to-hydrogen (STH) efficiency of the system, we developed a multiphysics model. While electronic and optical properties are computed with ab initio calculations, we implemented the detailed balance method and the Butler-Volmer kinetics to simulate the photoelectrochemical behaviour. Under realistic operating conditions, the system achieves a STH efficiency greater than 15%, which is higher than the critical 10% efficiency required to make SWS economically viable. Since our system is wireless and requires simple manufacturing processes (exfoliation), this result is remarkable.
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Affiliation(s)
- Paul Dalla Valle
- Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334 13397 Marseille France
| | - Nicolas Cavassilas
- Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334 13397 Marseille France
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40
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Liu Y, Elbanna A, Gao W, Pan J, Shen Z, Teng J. Interlayer Excitons in Transition Metal Dichalcogenide Semiconductors for 2D Optoelectronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2107138. [PMID: 34700359 DOI: 10.1002/adma.202107138] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/13/2021] [Indexed: 06/13/2023]
Abstract
Optoelectronic materials that allow on-chip integrated light signal emitting, routing, modulation, and detection are crucial for the development of high-speed and high-throughput optical communication and computing technologies. Interlayer excitons in 2D van der Waals heterostructures, where electrons and holes are bounded by Coulomb interaction but spatially localized in different 2D layers, have recently attracted intense attention for their enticing properties and huge potential in device applications. Here, a general view of these 2D-confined hydrogen-like bosonic particles and the state-of-the-art developments with respect to the frontier concepts and prototypes is presented. Staggered type-II band alignment enables expansion of the interlayer direct bandgap from the intrinsic visible in monolayers up to the near- or even mid-infrared spectrum. Owing to large exciton binding energy, together with ultralong lifetime, room-temperature exciton devices and observation of quantum behaviors are demonstrated. With the rapid advances, it can be anticipated that future studies of interlayer excitons will not only allow the construction of all-exciton information processing circuits but will also continue to enrich the panoply of ideas on quantum phenomena.
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Affiliation(s)
- Yuanda Liu
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Ahmed Elbanna
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore, 138634, Singapore
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 637371, Singapore
| | - Weibo Gao
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 637371, Singapore
- The Photonics Institute and Center for Disruptive Photonic Technologies, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Jisheng Pan
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Zexiang Shen
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 637371, Singapore
- The Photonics Institute and Center for Disruptive Photonic Technologies, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Jinghua Teng
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore, 138634, Singapore
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41
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Deng JP, Li HJ, Ma XF, Liu XY, Cui Y, Ma XJ, Li ZQ, Wang ZW. Self-Trapped Interlayer Excitons in van der Waals Heterostructures. J Phys Chem Lett 2022; 13:3732-3739. [PMID: 35445599 DOI: 10.1021/acs.jpclett.2c00565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The self-trapped state (STS) of the interlayer exciton (IX) has aroused enormous interest owing to its significant impact on the fundamental properties of the van der Waals heterostructures (vdWHs). Nevertheless, the microscopic mechanisms of STS are still controversial. Herein, we study the corrections of the binding energies of the IXs stemming from the exciton-interface optical phonon coupling in four kinds of vdWHs and find that these IXs are in the STS for the appropriate ratio of the electron and hole effective masses. We show that these self-trapped IXs could be classified into type I with the increasing binding energy in the tens of millielectronvolts range, which are very agreement with the red-shift of the IX spectra in experiments, and type II with the decreasing binding energy, which provides a possible explanation for the blue-shift and broad line width of the IX's spectra at low temperatures. Moreover, these two types of exciton states could be transformed into each other by adjusting the structural parameters of vdWHs. These results not only provide an in-depth understanding for the self-trapped mechanism but also shed light on the modulations of IXs in vdWHs.
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Affiliation(s)
- Jia-Pei Deng
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, School of Science, Tianjin University, Tianjin 300354, Tianjin, China
| | - Hong-Juan Li
- College of Physics and Intelligent Manufacturing Engineering, Chifeng University, Chifeng 024000, Inner Mongolia, China
| | - Xu-Fei Ma
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, School of Science, Tianjin University, Tianjin 300354, Tianjin, China
| | - Xiao-Yi Liu
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, School of Science, Tianjin University, Tianjin 300354, Tianjin, China
| | - Yu Cui
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, School of Science, Tianjin University, Tianjin 300354, Tianjin, China
| | - Xin-Jun Ma
- Research Team of Extreme Condition Physics, College of Mathematics and Physics, Inner Mongolia Minzu University, Tongliao 028043, Inner Mongolia, China
| | - Zhi-Qing Li
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, School of Science, Tianjin University, Tianjin 300354, Tianjin, China
| | - Zi-Wu Wang
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, School of Science, Tianjin University, Tianjin 300354, Tianjin, China
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42
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Barré E, Karni O, Liu E, O'Beirne AL, Chen X, Ribeiro HB, Yu L, Kim B, Watanabe K, Taniguchi T, Barmak K, Lui CH, Refaely-Abramson S, da Jornada FH, Heinz TF. Optical absorption of interlayer excitons in transition-metal dichalcogenide heterostructures. Science 2022; 376:406-410. [PMID: 35446643 DOI: 10.1126/science.abm8511] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Interlayer excitons, electron-hole pairs bound across two monolayer van der Waals semiconductors, offer promising electrical tunability and localizability. Because such excitons display weak electron-hole overlap, most studies have examined only the lowest-energy excitons through photoluminescence. We directly measured the dielectric response of interlayer excitons, which we accessed using their static electric dipole moment. We thereby determined an intrinsic radiative lifetime of 0.40 nanoseconds for the lowest direct-gap interlayer exciton in a tungsten diselenide/molybdenum diselenide heterostructure. We found that differences in electric field and twist angle induced trends in exciton transition strengths and energies, which could be related to wave function overlap, moiré confinement, and atomic reconstruction. Through comparison with photoluminescence spectra, this study identifies a momentum-indirect emission mechanism. Characterization of the absorption is key for applications relying on light-matter interactions.
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Affiliation(s)
- Elyse Barré
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA.,Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Ouri Karni
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA.,Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - Erfu Liu
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, USA
| | - Aidan L O'Beirne
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA.,Department of Physics, Stanford University, Stanford, CA 94305, USA
| | - Xueqi Chen
- Department of Physics, Stanford University, Stanford, CA 94305, USA
| | | | - Leo Yu
- Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - Bumho Kim
- Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Katayun Barmak
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA
| | - Chun Hung Lui
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, USA
| | - Sivan Refaely-Abramson
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Felipe H da Jornada
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Tony F Heinz
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA.,Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
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43
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Yang X, Wu R, Zheng B, Luo Z, You W, Liu H, Li L, Zhang Y, Tan Q, Liang D, Chen Y, Qu J, Yi X, Wang X, Zhou J, Duan H, Wang S, Chen S, Pan A. A Waveguide-Integrated Two-Dimensional Light-Emitting Diode Based on p-Type WSe 2/n-Type CdS Nanoribbon Heterojunction. ACS NANO 2022; 16:4371-4378. [PMID: 35191308 DOI: 10.1021/acsnano.1c10607] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Transition metal dichalcogenides (TMDs) have emerged as two-dimensional (2D) building blocks to construct nanoscale light sources. To date, a wide array of TMD-based light-emitting devices (LEDs) have been successfully demonstrated. Yet, their atomically thin and planar nature entails an additional waveguide/microcavity for effective optical routing/confinement. In this sense, integration of TMDs with electronically active photonic nanostructures to form a functional heterojunction is of crucial importance for 2D optoelectronic chips with reduced footprint and higher integration capacity. Here, we report a room-temperature waveguide-integrated light-emitting device based on a p-type monolayer (ML) tungsten diselenide (WSe2) and n-type cadmium sulfide (CdS) nanoribbon (NR) heterojunction diode. The hybrid LED exhibited clear rectification under forward biasing, giving pronounced electroluminescence (EL) at 1.65 eV from exciton resonances in ML WSe2. The integrated EL intensity against the driving current shows a superlinear profile at a high current level, implying a facilitated carrier injection via intervalley scattering. By leveraging CdS NR waveguides, the WSe2 EL can be efficiently coupled and further routed for potential optical interconnect functionalities. Our results manifest the waveguided LEDs as a dual-role module for TMD-based optoelectronic circuitries.
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Affiliation(s)
- Xin Yang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Rong Wu
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Biyuan Zheng
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Ziyu Luo
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Wenxia You
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Huawei Liu
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Lihui Li
- College of Physics and Electronics, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Yushuang Zhang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Qin Tan
- College of Physics and Electronics, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Delang Liang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Ying Chen
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Junyu Qu
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Xiao Yi
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Xingjun Wang
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, People's Republic of China
| | - Jun Zhou
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Hubei, People's Republic of China
| | - Huigao Duan
- College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, China
| | - Shuangyin Wang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Shula Chen
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
| | - Anlian Pan
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan, People's Republic of China
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44
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Karni O, Barré E, Pareek V, Georgaras JD, Man MKL, Sahoo C, Bacon DR, Zhu X, Ribeiro HB, O'Beirne AL, Hu J, Al-Mahboob A, Abdelrasoul MMM, Chan NS, Karmakar A, Winchester AJ, Kim B, Watanabe K, Taniguchi T, Barmak K, Madéo J, da Jornada FH, Heinz TF, Dani KM. Structure of the moiré exciton captured by imaging its electron and hole. Nature 2022; 603:247-252. [PMID: 35264760 DOI: 10.1038/s41586-021-04360-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 12/14/2021] [Indexed: 11/09/2022]
Abstract
Interlayer excitons (ILXs) - electron-hole pairs bound across two atomically thin layered semiconductors - have emerged as attractive platforms to study exciton condensation1-4, single-photon emission and other quantum information applications5-7. Yet, despite extensive optical spectroscopic investigations8-12, critical information about their size, valley configuration and the influence of the moiré potential remains unknown. Here, in a WSe2/MoS2 heterostructure, we captured images of the time-resolved and momentum-resolved distribution of both of the particles that bind to form the ILX: the electron and the hole. We thereby obtain a direct measurement of both the ILX diameter of around 5.2 nm, comparable with the moiré-unit-cell length of 6.1 nm, and the localization of its centre of mass. Surprisingly, this large ILX is found pinned to a region of only 1.8 nm diameter within the moiré cell, smaller than the size of the exciton itself. This high degree of localization of the ILX is backed by Bethe-Salpeter equation calculations and demonstrates that the ILX can be localized within small moiré unit cells. Unlike large moiré cells, these are uniform over large regions, allowing the formation of extended arrays of localized excitations for quantum technology.
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Affiliation(s)
- Ouri Karni
- Department of Applied Physics, Stanford University, Stanford, CA, USA.,SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Elyse Barré
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Vivek Pareek
- Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Johnathan D Georgaras
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Michael K L Man
- Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Chakradhar Sahoo
- Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan.,Tata Institute of Fundamental Research, Hyderabad, Gopanpally, Serlingampalli, Telangana, India
| | - David R Bacon
- Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Xing Zhu
- Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | | | - Aidan L O'Beirne
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Department of Physics, Stanford University, Stanford, CA, USA
| | - Jenny Hu
- Department of Applied Physics, Stanford University, Stanford, CA, USA
| | - Abdullah Al-Mahboob
- Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Mohamed M M Abdelrasoul
- Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Nicholas S Chan
- Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Arka Karmakar
- Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Andrew J Winchester
- Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Bumho Kim
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Katayun Barmak
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA
| | - Julien Madéo
- Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Felipe H da Jornada
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Tony F Heinz
- Department of Applied Physics, Stanford University, Stanford, CA, USA.,SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Keshav M Dani
- Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan.
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45
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Huang L, Krasnok A, Alú A, Yu Y, Neshev D, Miroshnichenko AE. Enhanced light-matter interaction in two-dimensional transition metal dichalcogenides. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 85:046401. [PMID: 34939940 DOI: 10.1088/1361-6633/ac45f9] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 12/16/2021] [Indexed: 05/27/2023]
Abstract
Two-dimensional (2D) transition metal dichalcogenide (TMDC) materials, such as MoS2, WS2, MoSe2, and WSe2, have received extensive attention in the past decade due to their extraordinary electronic, optical and thermal properties. They evolve from indirect bandgap semiconductors to direct bandgap semiconductors while their layer number is reduced from a few layers to a monolayer limit. Consequently, there is strong photoluminescence in a monolayer (1L) TMDC due to the large quantum yield. Moreover, such monolayer semiconductors have two other exciting properties: large binding energy of excitons and valley polarization. These properties make them become ideal materials for various electronic, photonic and optoelectronic devices. However, their performance is limited by the relatively weak light-matter interactions due to their atomically thin form factor. Resonant nanophotonic structures provide a viable way to address this issue and enhance light-matter interactions in 2D TMDCs. Here, we provide an overview of this research area, showcasing relevant applications, including exotic light emission, absorption and scattering features. We start by overviewing the concept of excitons in 1L-TMDC and the fundamental theory of cavity-enhanced emission, followed by a discussion on the recent progress of enhanced light emission, strong coupling and valleytronics. The atomically thin nature of 1L-TMDC enables a broad range of ways to tune its electric and optical properties. Thus, we continue by reviewing advances in TMDC-based tunable photonic devices. Next, we survey the recent progress in enhanced light absorption over narrow and broad bandwidths using 1L or few-layer TMDCs, and their applications for photovoltaics and photodetectors. We also review recent efforts of engineering light scattering, e.g., inducing Fano resonances, wavefront engineering in 1L or few-layer TMDCs by either integrating resonant structures, such as plasmonic/Mie resonant metasurfaces, or directly patterning monolayer/few layers TMDCs. We then overview the intriguing physical properties of different van der Waals heterostructures, and their applications in optoelectronic and photonic devices. Finally, we draw our opinion on potential opportunities and challenges in this rapidly developing field of research.
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Affiliation(s)
- Lujun Huang
- School of Engineering and Information Technology, University of New South Wales, Canberra, ACT, 2600, Australia
| | - Alex Krasnok
- Department of Electrical and Computer Engineering, Florida International University, Miami, FL 33174, United States of America
| | - Andrea Alú
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, NY 10031, United States of America
- Physics Program, Graduate Center, City University of New York, New York, NY 10016, United States of America
| | - Yiling Yu
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Dragomir Neshev
- ARC Centre of Excellence for Transformative Meta-Optical Systems (TMOS), Department of Electronic Materials Engineering, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - Andrey E Miroshnichenko
- School of Engineering and Information Technology, University of New South Wales, Canberra, ACT, 2600, Australia
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46
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Ouyang W, Sofer R, Gao X, Hermann J, Tkatchenko A, Kronik L, Urbakh M, Hod O. Anisotropic Interlayer Force Field for Transition Metal Dichalcogenides: The Case of Molybdenum Disulfide. J Chem Theory Comput 2021; 17:7237-7245. [PMID: 34719931 PMCID: PMC8592503 DOI: 10.1021/acs.jctc.1c00782] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Indexed: 11/28/2022]
Abstract
An anisotropic interlayer force field that describes the interlayer interactions in molybdenum disulfide (MoS2) is presented. The force field is benchmarked against density functional theory calculations for both bilayer and bulk systems within the Heyd-Scuseria-Ernzerhof hybrid density functional approximation, augmented by a nonlocal many-body dispersion treatment of long-range correlation. The parametrization yields good agreement with the reference calculations of binding energy curves and sliding potential energy surfaces for both bilayer and bulk configurations. Benchmark calculations for the phonon spectra of bulk MoS2 provide good agreement with experimental data, and the calculated bulk modulus falls in the lower part of experimentally measured values. This indicates the accuracy of the interlayer force field near equilibrium. Under external pressures up to 20 GPa, the developed force field provides a good description of compression curves. At higher pressures, deviations from experimental data grow, signifying the validity range of the developed force field.
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Affiliation(s)
- Wengen Ouyang
- Department
of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China
| | - Reut Sofer
- School
of Chemistry and The Sackler Center for Computational Molecular and
Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Xiang Gao
- School
of Chemistry and The Sackler Center for Computational Molecular and
Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Jan Hermann
- Machine
Learning Group, TU Berlin, Marchstr. 23, 10587 Berlin, Germany
- Department
of Mathematics, FU Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Alexandre Tkatchenko
- Department
of Physics and Materials Science, University
of Luxembourg, L-1511 Luxembourg City, Luxembourg
| | - Leeor Kronik
- Department
of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovoth 76100, Israel
| | - Michael Urbakh
- School
of Chemistry and The Sackler Center for Computational Molecular and
Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Oded Hod
- School
of Chemistry and The Sackler Center for Computational Molecular and
Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
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47
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Yang J, Jiang S, Xie J, Jiang H, Xu S, Zhang K, Shi Y, Zhang Y, Zeng Z, Fang G, Wang T, Su F. Identifying the Intermediate Free-Carrier Dynamics Across the Charge Separation in Monolayer MoS 2/ReSe 2 Heterostructures. ACS NANO 2021; 15:16760-16768. [PMID: 34549939 DOI: 10.1021/acsnano.1c06822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Van der Waals heterostructures composed of different two-dimensional films offer a unique platform for engineering and promoting photoelectric performances, which highly demands the understanding of photocarrier dynamics. Herein, large-scale vertically stacked heterostructures with MoS2 and ReSe2 monolayers are fabricated. Correspondingly, the carrier dynamics have been thoroughly investigated using different ultrafast spectroscopies, including Terahertz (THz) emission spectroscopy, time-resolved THz spectroscopy (TRTS), and near-infrared optical pump-probe spectroscopy (OPPS), providing complementary dynamic information for the out-of-plane charge separation and in-plane charge transport at different stages. The initial charge transfer (CT) within the first 170 fs, generating a transient directional current, is directly demonstrated by the THz emissions. Furthermore, the TRTS explicitly unveils an intermediate free-carrier relaxation pathway, featuring a pronounced augmentation of THz photoconductivity compared to the isolated ReSe2 layer, which likely contains the evolution from immigrant hot charged free carriers to bounded interlayer excitons (∼0.7 ps) and the surface defect trapping (∼13 ps). In addition, the OPPS reveals a distinct enhancement in the saturable absorption along with long-lived dynamics (∼365 ps), which originated from the CT and interlayer exciton recombination. Our work provides comprehensive insight into the photocarrier dynamics across the charge separation and will help with the development of optoelectronic devices based on ReSe2-MoS2 heterostructures.
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Affiliation(s)
- Jin Yang
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
- University of Science and Technology of China, Hefei 230026, China
| | - Shaolong Jiang
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jiafeng Xie
- GBA branch of Aerospace Information Research Institute, Chinese Academy of Sciences, Guangzhou 510700, China
| | - Huachao Jiang
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - Shujuan Xu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
- University of Science and Technology of China, Hefei 230026, China
| | - Kai Zhang
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - Yuping Shi
- Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
| | - Yanfeng Zhang
- Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
| | - Zhi Zeng
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - Guangyou Fang
- GBA branch of Aerospace Information Research Institute, Chinese Academy of Sciences, Guangzhou 510700, China
| | - Tianwu Wang
- GBA branch of Aerospace Information Research Institute, Chinese Academy of Sciences, Guangzhou 510700, China
| | - Fuhai Su
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
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48
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Zimmermann JE, Axt M, Mooshammer F, Nagler P, Schüller C, Korn T, Höfer U, Mette G. Ultrafast Charge-Transfer Dynamics in Twisted MoS 2/WSe 2 Heterostructures. ACS NANO 2021; 15:14725-14731. [PMID: 34520661 DOI: 10.1021/acsnano.1c04549] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Two-dimensional transition metal dichalcogenides offer a fascinating platform for creating van der Waals heterojunctions with exciting physical properties. Because of their typical type-II band alignment, photoexcited electrons and holes can separate via interfacial charge transfer. Furthermore, the relative crystallographic alignment of the individual layers in these heterostructures represents an important degree of freedom. Based on both effects, various fascinating ideas for applications in optoelectronics and valleytronics have been suggested. Despite its utmost importance for the design and efficiency of potential devices, the nature and the dynamics of ultrafast charge transfer are not yet well understood. This is mainly because the charge transfer can be surprisingly fast, usually faster than the temporal resolution of previous experimental approaches. Here, we apply time- and polarization-resolved second-harmonic imaging microscopy to investigate the charge-transfer dynamics for three MoS2/WSe2 heterostructures with different stacking angles at a previously unattainable time resolution of ≈10 fs. For 1.70 eV excitation energy, electron transfer from WSe2 to MoS2 is found to depend considerably on the stacking angle with the fastest transfer time observed to be as short as 12 fs. At 1.85 eV excitation energy, ultrafast hole transfer from MoS2 to hybridized states at the Γ-point and to the K-points of WSe2 has to be considered. Surprisingly, the corresponding decay dynamics show only a minor stacking-angle dependence indicating that radiative recombination of momentum-space indirect Γ-K excitons becomes the dominant decay route for all samples.
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Affiliation(s)
- Jonas E Zimmermann
- Fachbereich Physik und Zentrum für Materialwissenschaften, Philipps-Universität, 35032 Marburg, Germany
| | - Marleen Axt
- Fachbereich Physik und Zentrum für Materialwissenschaften, Philipps-Universität, 35032 Marburg, Germany
| | - Fabian Mooshammer
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, 93053 Regensburg, Germany
| | - Philipp Nagler
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, 93053 Regensburg, Germany
| | - Christian Schüller
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, 93053 Regensburg, Germany
| | - Tobias Korn
- Institut für Physik, Universität Rostock, 18059 Rostock, Germany
| | - Ulrich Höfer
- Fachbereich Physik und Zentrum für Materialwissenschaften, Philipps-Universität, 35032 Marburg, Germany
| | - Gerson Mette
- Fachbereich Physik und Zentrum für Materialwissenschaften, Philipps-Universität, 35032 Marburg, Germany
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49
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Yao Q, Bie YQ, Chen J, Li J, Li F, Cao Z. Anapole enhanced on-chip routing of spin-valley photons in 2D materials for silicon integrated optical communication. OPTICS LETTERS 2021; 46:4080-4083. [PMID: 34469944 DOI: 10.1364/ol.433457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 07/16/2021] [Indexed: 06/13/2023]
Abstract
Controlling the propagation direction of polarized light is crucial for optical communications and functional optical components. However, all-dielectric on-chip technology exploiting valley photon emission in transition metal dichalcogenides with enhanced emission has yet to be fully explored. Here, we report a design for enhancing valley emission and manipulating valley photon propagation based on degenerate non-radiating anapole states. By placing circularly polarized dipoles on top of a C4 symmetric cross-slotted silicon disk, the rotating anapole state is excited with a Purcell factor up to two orders. In addition, the photon coupled to the preferred direction of the waveguide are about 2 times larger than that to the opposite direction. Our design could pave the way for realizing on-chip valley-dependent optical communication.
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Wu K, Zhong H, Guo Q, Tang J, Zhang J, Qian L, Shi Z, Zhang C, Yuan S, Zhang S, Xu H. Identification of twist-angle-dependent excitons in WS2/WSe2 heterobilayers. Natl Sci Rev 2021; 9:nwab135. [PMID: 35795458 PMCID: PMC9252742 DOI: 10.1093/nsr/nwab135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 06/30/2021] [Accepted: 07/12/2021] [Indexed: 11/13/2022] Open
Abstract
Abstract
Stacking atomically thin films enables artificial construction of van der Waals heterostructures with exotic functionalities such as superconductivity, the quantum Hall effect, and engineered light-matter interactions. In particular, heterobilayers composed of monolayer transition metal dichalcogenides have attracted significant interest due to their controllable interlayer coupling and trapped valley excitons in moiré superlattices. However, the identification of twist-angle-modulated optical transitions in heterobilayers is sometimes controversial since both momentum-direct (K-K) and -indirect excitons reside on the low energy side of the bright exciton in the monolayer constituents. Here, we attribute the optical transition at approximately 1.35 eV in the WS2/WSe2 heterobilayer to an indirect Γ-K transition based on a systematic analysis and comparison of experimental PL spectra with theoretical calculations. The exciton wavefunction obtained by the state-of-the-art GW-Bethe-Salpeter equation (GW-BSE) approach indicates that both the electron and hole of the exciton are contributed by the WS2 layer. Polarization-resolved k-space imaging further confirms that the transition dipole moment of this optical transition is dominantly in-plane and is independent of the twist angle. The calculated absorption spectrum predicts that the usually called interlayer exciton peak coming from the K-K transition is located at 1.06 eV, but with a much weaker amplitude. Our work provides new insights into understanding the steady-state and dynamic properties of twist-angle-dependent excitons in van der Waals heterostructures.
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Affiliation(s)
- Ke Wu
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hongxia Zhong
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Quanbing Guo
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Jibo Tang
- The Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Jing Zhang
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Lihua Qian
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhifeng Shi
- Key Laboratory of Materials Physics of Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450052, China
| | - Chendong Zhang
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Shengjun Yuan
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, 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
| | - 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
- The Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
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