1
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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. [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
- Center for Atomistic Modelling and Materials Design, IIT Madras, Chennai 600036, 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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2
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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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3
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Zhang D, Ge C, Wang Y, Xia Y, Zhao H, Yao C, Chen Y, Ma C, Tong Q, Pan A, Wang X. Enhancing Layer-Engineered Interlayer Exciton Emission and Valley Polarization in van der Waals Heterostructures via Strain. ACS NANO 2024; 18:17672-17680. [PMID: 38920321 DOI: 10.1021/acsnano.4c02377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
Layer-engineered interlayer excitons from heterostructures of transition-metal dichalcogenides (TMDCs) exhibit a rich variety of emissive states and intriguing valley spin-selection rules, the effective modulation of which is crucial for excitonic physics and related device applications. Strain or high pressure provides the possibility to tune the energy of the interlayer excitons; however, the reported emission intensity is substantially quenched, which greatly limits their practical application in optoelectronic devices. Here, via applying uniaxial strain based on polyvinyl alcohol (PVA) encapsulation technique, we report enhanced layer-engineered interlayer exciton emission intensity with largely modulated emission energy in WSe2/WS2 heterobilayer and heterotrilayer. Both momentum-direct and momentum-indirect interlayer excitons were observed, and their emission energies show an opposite shift tendency upon applied strain, which agrees with our DFT calculations. We further demonstrate that intralayer and interlayer exciton states with low phonon interactions can be modulated through the mechanical strain applied to the PVA substrate at low temperatures. Due to strain-induced breaking of the 3-fold rotational symmetry, we observe the enhanced valley polarization of interlayer excitons. Our study contributes to the understanding and modulation of the optical properties of interlayer excitons, which could be exploited for optoelectronic device applications.
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Affiliation(s)
- Danliang Zhang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Cuihuang Ge
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Youwen Wang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Yang Xia
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Haipeng Zhao
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Chengdong Yao
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Ying Chen
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Chao Ma
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Qingjun Tong
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Anlian Pan
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Xiao Wang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, College of Materials Science and Engineering, Hunan University, Changsha 410082, China
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4
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Dai D, Fu B, Yang J, Yang L, Yan S, Chen X, Li H, Zuo Z, Wang C, Jin K, Gong Q, Xu X. Twist angle-dependent valley polarization switching in heterostructures. SCIENCE ADVANCES 2024; 10:eado1281. [PMID: 38748802 PMCID: PMC11095485 DOI: 10.1126/sciadv.ado1281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 04/12/2024] [Indexed: 05/19/2024]
Abstract
The twist engineering of moiré superlattice in van der Waals heterostructures of transition metal dichalcogenides can manipulate valley physics of interlayer excitons (IXs), paving the way for next-generation valleytronic devices. However, the twist angle-dependent control of excitonic potential on valley polarization is not investigated so far in electrically controlled heterostructures and the physical mechanism underneath needs to be explored. Here, we demonstrate the dependence of both polarization switching and degree of valley polarization on the moiré period. We also find the mechanisms to reveal the modulation of twist angle on the exciton potential and the electron-hole exchange interaction, which elucidate the experimentally observed twist angle-dependent valley polarization of IXs. Furthermore, we realize the valley-addressable devices based on polarization switch. Our work demonstrates the manipulation of the valley polarization of IXs by tunning twist angle in electrically controlled heterostructures, which opens an avenue for electrically controlling the valley degrees of freedom in twistronic devices.
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Affiliation(s)
- Danjie Dai
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bowen Fu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Jingnan Yang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Longlong Yang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Sai Yan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiqing Chen
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Hancong Li
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Zhanchun Zuo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Can Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Kuijuan Jin
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Qihuang Gong
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China
| | - Xiulai Xu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China
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5
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Meneghini G, Brem S, Malic E. Excitonic Thermalization Bottleneck in Twisted TMD Heterostructures. NANO LETTERS 2024; 24:4505-4511. [PMID: 38578047 DOI: 10.1021/acs.nanolett.4c00450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Twisted van der Waals heterostructures show intriguing interface exciton physics, including hybridization effects and emergence of moiré potentials. Recent experiments have revealed that moiré-trapped excitons exhibit remarkable dynamics, where excited states show lifetimes that are several orders of magnitude longer than in monolayers. The origin of this behavior is still under debate. Based on a microscopic many-particle approach, we investigate the phonon-driven relaxation cascade of nonequilibrium moiré excitons in the exemplary MoSe2-WSe2 heterostructure. We track exciton relaxation pathways across different moiré mini-bands and identify the phonon-scattering channels assisting the spatial redistribution of excitons into low-energy pockets of the moiré potential. We unravel a phonon bottleneck in the flat band structure at low twist angles preventing excitons from fully thermalizing into the lowest state, explaining the measured enhanced emission intensity and lifetime of excited moiré excitons. Overall, our work provides important insights into exciton relaxation dynamics in flat-band exciton materials.
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Affiliation(s)
- Giuseppe Meneghini
- Department of Physics, Philipps University of Marburg, 35037 Marburg, Germany
| | - Samuel Brem
- Department of Physics, Philipps University of Marburg, 35037 Marburg, Germany
| | - Ermin Malic
- Department of Physics, Philipps University of Marburg, 35037 Marburg, Germany
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6
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Fang N, Chang YR, Fujii S, Yamashita D, Maruyama M, Gao Y, Fong CF, Kozawa D, Otsuka K, Nagashio K, Okada S, Kato YK. Room-temperature quantum emission from interface excitons in mixed-dimensional heterostructures. Nat Commun 2024; 15:2871. [PMID: 38605019 PMCID: PMC11009238 DOI: 10.1038/s41467-024-47099-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 03/19/2024] [Indexed: 04/13/2024] Open
Abstract
The development of van der Waals heterostructures has introduced unconventional phenomena that emerge at atomically precise interfaces. For example, interlayer excitons in two-dimensional transition metal dichalcogenides show intriguing optical properties at low temperatures. Here we report on room-temperature observation of interface excitons in mixed-dimensional heterostructures consisting of two-dimensional tungsten diselenide and one-dimensional carbon nanotubes. Bright emission peaks originating from the interface are identified, spanning a broad energy range within the telecommunication wavelengths. The effect of band alignment is investigated by systematically varying the nanotube bandgap, and we assign the new peaks to interface excitons as they only appear in type-II heterostructures. Room-temperature localization of low-energy interface excitons is indicated by extended lifetimes as well as small excitation saturation powers, and photon correlation measurements confirm antibunching. With mixed-dimensional van der Waals heterostructures where band alignment can be engineered, new opportunities for quantum photonics are envisioned.
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Affiliation(s)
- N Fang
- Nanoscale Quantum Photonics Laboratory, RIKEN Cluster for Pioneering Research, Saitama, Japan.
| | - Y R Chang
- Nanoscale Quantum Photonics Laboratory, RIKEN Cluster for Pioneering Research, Saitama, Japan
| | - S Fujii
- Quantum Optoelectronics Research Team, RIKEN Center for Advanced Photonics, Saitama, Japan
- Department of Physics, Keio University, Yokohama, Japan
| | - D Yamashita
- Quantum Optoelectronics Research Team, RIKEN Center for Advanced Photonics, Saitama, Japan
- Platform Photonics Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki, Japan
| | - M Maruyama
- Department of Physics, University of Tsukuba, Ibaraki, Japan
| | - Y Gao
- Department of Physics, University of Tsukuba, Ibaraki, Japan
| | - C F Fong
- Nanoscale Quantum Photonics Laboratory, RIKEN Cluster for Pioneering Research, Saitama, Japan
| | - D Kozawa
- Nanoscale Quantum Photonics Laboratory, RIKEN Cluster for Pioneering Research, Saitama, Japan
- Quantum Optoelectronics Research Team, RIKEN Center for Advanced Photonics, Saitama, Japan
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, Ibaraki, Japan
| | - K Otsuka
- Nanoscale Quantum Photonics Laboratory, RIKEN Cluster for Pioneering Research, Saitama, Japan
- Department of Mechanical Engineering, The University of Tokyo, Tokyo, Japan
| | - K Nagashio
- Department of Materials Engineering, The University of Tokyo, Tokyo, Japan
| | - S Okada
- Department of Physics, University of Tsukuba, Ibaraki, Japan
| | - Y K Kato
- Nanoscale Quantum Photonics Laboratory, RIKEN Cluster for Pioneering Research, Saitama, Japan.
- Quantum Optoelectronics Research Team, RIKEN Center for Advanced Photonics, Saitama, Japan.
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7
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Pelella A, Intonti K, Durante O, Kumar A, Viscardi L, De Stefano S, Romano P, Giubileo F, Neill H, Patil V, Ansari L, Roycroft B, Hurley PK, Gity F, Di Bartolomeo A. Multilayer WS 2 for low-power visible and near-infrared phototransistors. DISCOVER NANO 2024; 19:57. [PMID: 38528187 DOI: 10.1186/s11671-024-04000-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 03/18/2024] [Indexed: 03/27/2024]
Abstract
Mechanically exfoliated multilayer WS2 flakes are used as the channel of field effect transistors for low-power photodetection in the visible and near-infrared (NIR) spectral range. The electrical characterization as a function of the temperature reveals devices with n-type conduction and slightly different Schottky barriers at the drain and source contacts. The WS2 phototransistors can be operated in self-powered mode, yielding both a current and a voltage when exposed to light. The spectral photoresponse in the visible and the NIR ranges shows a high responsivity (4.5 μA/W) around 1250 nm, making the devices promising for telecommunication applications.
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Affiliation(s)
- Aniello Pelella
- Department of Science and Technology, University of Sannio, Via De Sanctis 59/A, 82100, Benevento, Italy
| | - Kimberly Intonti
- Department of Physics "E. R. Caianiello", University of Salerno, Via Giovanni Paolo II, 84084, Fisciano, Salerno, Italy
- CNR-SPIN Salerno, Via Giovanni Paolo II, 84084, Fisciano, Italy
| | - Ofelia Durante
- Department of Physics "E. R. Caianiello", University of Salerno, Via Giovanni Paolo II, 84084, Fisciano, Salerno, Italy
| | - Arun Kumar
- Department of Physics "E. R. Caianiello", University of Salerno, Via Giovanni Paolo II, 84084, Fisciano, Salerno, Italy
| | - Loredana Viscardi
- Department of Physics "E. R. Caianiello", University of Salerno, Via Giovanni Paolo II, 84084, Fisciano, Salerno, Italy
- CNR-SPIN Salerno, Via Giovanni Paolo II, 84084, Fisciano, Italy
| | - Sebastiano De Stefano
- Department of Physics "E. R. Caianiello", University of Salerno, Via Giovanni Paolo II, 84084, Fisciano, Salerno, Italy
| | - Paola Romano
- Department of Science and Technology, University of Sannio, Via De Sanctis 59/A, 82100, Benevento, Italy
- CNR-SPIN Salerno, Via Giovanni Paolo II, 84084, Fisciano, Italy
| | | | - Hazel Neill
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, T12 R5CP, Ireland
| | - Vilas Patil
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, T12 R5CP, Ireland
| | - Lida Ansari
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, T12 R5CP, Ireland
| | - Brendan Roycroft
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, T12 R5CP, Ireland
| | - Paul K Hurley
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, T12 R5CP, Ireland
- School of Chemistry, University College Cork, Cork, Ireland
| | - Farzan Gity
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, T12 R5CP, Ireland
| | - Antonio Di Bartolomeo
- Department of Physics "E. R. Caianiello", University of Salerno, Via Giovanni Paolo II, 84084, Fisciano, Salerno, Italy.
- CNR-SPIN Salerno, Via Giovanni Paolo II, 84084, Fisciano, Italy.
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8
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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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9
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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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10
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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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11
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Tan QH, Li YM, Lai JM, Sun YJ, Zhang Z, Song F, Robert C, Marie X, Gao W, Tan PH, Zhang J. Quantum interference between dark-excitons and zone-edged acoustic phonons in few-layer WS 2. Nat Commun 2023; 14:88. [PMID: 36604415 PMCID: PMC9816112 DOI: 10.1038/s41467-022-35714-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 12/15/2022] [Indexed: 01/07/2023] Open
Abstract
Fano resonance which describes a quantum interference between continuum and discrete states, provides a unique method for studying strongly interacting physics. Here, we report a Fano resonance between dark excitons and zone-edged acoustic phonons in few-layer WS2 by using the resonant Raman technique. The discrete phonons with large momentum at the M-point of the Brillouin zone and the continuum dark exciton states related to the optically forbidden transition at K and Q valleys are coupled by the exciton-phonon interactions. We observe rich Fano resonance behaviors across layers and modes defined by an asymmetry-parameter q: including constructive interference with two mirrored asymmetry Fano peaks (weak coupling, q > 1 and q < - 1), and destructive interference with Fano dip (strong coupling, ∣q∣ < < 1). Our results provide new insight into the exciton-phonon quantum interference in two-dimensional semiconductors, where such interferences play a key role in their transport, optical, and thermodynamic properties.
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Affiliation(s)
- Qing-Hai Tan
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China ,grid.59025.3b0000 0001 2224 0361Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore, Singapore
| | - Yun-Mei Li
- grid.12955.3a0000 0001 2264 7233Department of Physics, Xiamen University, Xiamen, 361005 China
| | - Jia-Min Lai
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Yu-Jia Sun
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Zhe Zhang
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Feilong Song
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Cedric Robert
- grid.462768.90000 0004 0383 4043University of Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - Xavier Marie
- grid.462768.90000 0004 0383 4043University of Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - Weibo Gao
- grid.59025.3b0000 0001 2224 0361Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore, Singapore ,grid.59025.3b0000 0001 2224 0361The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, 637371 Singapore, Singapore ,grid.4280.e0000 0001 2180 6431Centre for Quantum Technologies, National University of Singapore, Singapore, 117543 Singapore
| | - Ping-Heng Tan
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Jun Zhang
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China ,grid.410726.60000 0004 1797 8419CAS Center of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, 100049 China
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12
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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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13
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Li S, Zheng H, Wu B, Ding J, He J, Liu Z, Liu Y. Layer-dependent excitonic valley polarization properties in MoS 2-WS 2 heterostructures. OPTICS LETTERS 2022; 47:5861-5864. [PMID: 37219121 DOI: 10.1364/ol.474799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 10/13/2022] [Indexed: 05/24/2023]
Abstract
In this work, we investigate the polarization of the excitonics valley in MoS2-WS2 heterostructures using circular polarization-resolved photoluminescence. The valley polarization is the largest (≈28.45%) in the 1L-1L MoS2-WS2 heterostructure and the polarizability of AWS2 decreases as the number of WS2 layers increases. We further observed a redshift of exciton XMoS2- in MoS2-WS2 heterostructures with the increase of WS2 layers, which is attributed to the displacement of the MoS2 band edge, indicating the layer-sensitive optical properties of the MoS2-WS2 heterostructure. Our findings shed light on the understanding of exciton behavior in multilayer MoS2-WS2 heterostructures that may promote their potential applications in optoelectronic devices.
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14
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Yao W, Yang D, Chen Y, Hu J, Li J, Li D. Layer-Number Engineered Momentum-Indirect Interlayer Excitons with Large Spectral Tunability. NANO LETTERS 2022; 22:7230-7237. [PMID: 36036787 DOI: 10.1021/acs.nanolett.2c02742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Interlayer excitons (IXs) in type II van der Waals (vdW) heterostructures are equipped with an oriented permanent dipole moment and long lifetime and thus would allow promising applications in excitonic and optoelectronic devices. However, based on the widely studied heterostructures of transition-metal dichalcogenides (TMDs), IX emission is greatly influenced by the lattice mismatch and geometric misalignment between the constituent layers, increasing the complexity of the device fabrication. Here, we report on the robust momentum-indirect IX emission in TMD/two-dimensional (2D) perovskite vdW heterostructures, which were fabricated without considering the orientation arrangement or momentum mismatch. The IXs show a large diffusion coefficient of ∼10 cm2 s-1, and importantly the IX emission energy can be widely tuned from 1.3 to 1.6 eV via changing the layer number of the 2D perovskite or the thickness of TMD flakes, shedding light on the applications of vdW interface engineering to broad-spectrum optoelectronics.
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Affiliation(s)
- Wendian Yao
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Dong Yang
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Yingying Chen
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Junchao Hu
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Junze Li
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Dehui Li
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
- Wuhan National Laboratory for Optoelectronics, Optical Valley Laboratory, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
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15
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Zheng SW, Wang D, Wang HY, Wang H, Chen X, Zhao LY, Wang L, Li XB, Sun HB. Spin-Valley Depolarization in van der Waals Heterostructures. J Phys Chem Lett 2022; 13:5501-5507. [PMID: 35695739 DOI: 10.1021/acs.jpclett.2c01414] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The appearance of van der Waals heterostructures offers a new solution to valleytronics. Here, we observe the spin-valley depolarization process of electrons and holes in type-II MoS2-WSe2 heterostructures simultaneously for the first time by valley-resolved broad-band femtosecond pump-probe experiments. The different depolarization paths between electrons and holes make them have different spin-valley polarization lifetimes. The spin-valley depolarization pathway of holes is mainly dominated by a phonon-assisted intervalley scattering process, while intra- and intervalley coupling can trigger additional depolarization pathways for electrons. The hole polarization lifetime can be further prolonged to more than three times in trilayer heterostructure 2MoS2-WSe2. For MoS2-WS2 that has strong orbital hybridization of Mo and W atoms, both electrons and holes lose the spin-valley polarization extremely soon after charge separation, behaving similarly to intraexcitons in a monolayer. Our work advances the basic understanding of spin-valley depolarization of van der Waals heterostructures and facilitates the effort toward longer lifetime valleytronic devices for information transfer and storage applications.
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Affiliation(s)
- Shu-Wen Zheng
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Dan Wang
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06511, United States
| | - Hai-Yu Wang
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Hai Wang
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Xin Chen
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Le-Yi Zhao
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Lei Wang
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Xian-Bin Li
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Hong-Bo Sun
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Haidian, Beijing 100084, China
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16
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Zhu M, Zhang Z, Zhang T, Liu D, Zhang H, Zhang Z, Li Z, Cheng Y, Huang W. Exchange between Interlayer and Intralayer Exciton in WSe 2/WS 2 Heterostructure by Interlayer Coupling Engineering. NANO LETTERS 2022; 22:4528-4534. [PMID: 35588493 DOI: 10.1021/acs.nanolett.2c01353] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Because of type-II band alignment, interlayer exciton (IX) is found in a van der Waals (vdW) heterostructure (HS) formed by two monolayers of transition-metal dichalcogenides. Manipulation of IXs is of great importance for excitonic integrated devices. Here, we demonstrate that high pressure and tensile strain can be applied to enhance and reduce interlayer coupling of WSe2/WS2 HS, respectively. High pressure induces the transform of intralayer excitons to IX, while tensile strain leads to the transform of IXs to intralayer excitons. In addition, there is a direct-to-indirect band gap transition of WSe2/WS2 HS. The interlayer distance of WSe2/WS2 HS is reduced under high pressure, but it increased under uniaxial tensile strain from first-principles calculations. The calculated band structures explain well the transformation between interlayer and intralayer excitons of WSe2/WS2 HS. This work demonstrates the exchange of interlayer and intralayer excitons and paves the way to manipulate excitons of HS for excitonic applications.
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Affiliation(s)
- Mengqi Zhu
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, China
| | - Zhineng Zhang
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, China
| | - Tao Zhang
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, China
| | - Dongdong Liu
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, China
| | - Hao Zhang
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, China
| | - Zhenxiao Zhang
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, China
| | - Zhuolun Li
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, China
| | - Yingchun Cheng
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, China
| | - Wei Huang
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, China
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
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17
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Wu B, Zheng H, Li S, Ding J, He J, Zeng Y, Chen K, Liu Z, Chen S, Pan A, Liu Y. Evidence for moiré intralayer excitons in twisted WSe 2/WSe 2 homobilayer superlattices. LIGHT, SCIENCE & APPLICATIONS 2022; 11:166. [PMID: 35650176 PMCID: PMC9160078 DOI: 10.1038/s41377-022-00854-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 04/27/2022] [Accepted: 05/15/2022] [Indexed: 05/10/2023]
Abstract
Recent advances in twisted van der Waals heterostructure superlattices have emerged as a powerful and attractive platform for exploring novel condensed matter physics due to the interplay between the moiré potential and Coulomb interactions. The moiré superlattices act as a periodic confinement potential in space to capture interlayer excitons (IXs), resulting in moiré exciton arrays, which provide opportunities for quantum emitters and many-body physics. The observation of moiré IXs in twisted transition-metal dichalcogenide (TMD) heterostructures has recently been widely reported. However, the capture and study of the moiré intralayer excitons based on TMD twisted homobilayer (T-HB) remain elusive. Here, we report the observation of moiré intralayer excitons in a WSe2/WSe2 T-HB with a small twist angle by measuring PL spectrum. The multiple split peaks with an energy range of 1.55-1.73 eV are different from that of the monolayer WSe2 exciton peaks. The split peaks were caused by the trapping of intralayer excitons via the moiré potential. The confinement effect of the moiré potential on the moiré intralayer excitons was further demonstrated by the changing of temperature, laser power, and valley polarization. Our findings provide a new avenue for exploring new correlated quantum phenomena and their applications.
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Affiliation(s)
- Biao Wu
- School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, China
- State Key Laboratory of High-Performance Complex Manufacturing, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, China
| | - Haihong Zheng
- School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, China
- State Key Laboratory of High-Performance Complex Manufacturing, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, China
| | - Shaofei Li
- School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, China
| | - Junnan Ding
- School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, China
| | - Jun He
- School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, China
| | - Yujia Zeng
- Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha, 410082, China
| | - Keqiu Chen
- Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha, 410082, China
| | - Zongwen Liu
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW, 2006, Australia
- The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Shula Chen
- Hunan Institute of Optoelectronic Integration, College of Materials Science and Engineering, Hunan University, Changsha, Hunan, 410082, China
| | - Anlian Pan
- Hunan Institute of Optoelectronic Integration, College of Materials Science and Engineering, Hunan University, Changsha, Hunan, 410082, China.
| | - Yanping Liu
- School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, China.
- State Key Laboratory of High-Performance Complex Manufacturing, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, China.
- Shenzhen Research Institute of Central South University, A510a, Virtual University Building, Southern District, High-tech Industrial Park, Yuehai Street, Nanshan District, Shenzhen, China.
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