中国物理B ›› 2025, Vol. 34 ›› Issue (9): 96701-096701.doi: 10.1088/1674-1056/add504

所属专题： TOPICAL REVIEW — Exciton physics: Fundamentals, materials and devices

• • 上一篇    下一篇

Exciton and valley dynamics in WSe2/GaAs heterostructure

Xin Wei(魏鑫)1,2, Yuanhe Li(李元和)1,2, Wenkai Zhu(朱文凯)1,2, Rongkun Han(韩荣坤)1,2, Jianhua Zhao(赵建华)1,3, Kaiyou Wang(王开友)1,2, and Xinhui Zhang(张新惠)1,2,†   

  1. 1 State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China;
    2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China;
    3 National Key Laboratory of Spintronics, Hangzhou International Innovation Institute, Beihang University, Hangzhou 311115, China
  • 收稿日期:2025-03-20 修回日期:2025-04-25 接受日期:2025-05-07 出版日期:2025-08-21 发布日期:2025-08-28
  • 通讯作者: Xinhui Zhang E-mail:xinhuiz@semi.ac.cn
  • 基金资助:
    This work was funded by the National Key Research and Development Program of China (Grant No. 2022YFA1405100) and the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB43000000).

Exciton and valley dynamics in WSe2/GaAs heterostructure

Xin Wei(魏鑫)1,2, Yuanhe Li(李元和)1,2, Wenkai Zhu(朱文凯)1,2, Rongkun Han(韩荣坤)1,2, Jianhua Zhao(赵建华)1,3, Kaiyou Wang(王开友)1,2, and Xinhui Zhang(张新惠)1,2,†   

  1. 1 State Key Laboratory of Semiconductor Physics and Chip Technologies, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China;
    2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China;
    3 National Key Laboratory of Spintronics, Hangzhou International Innovation Institute, Beihang University, Hangzhou 311115, China
  • Received:2025-03-20 Revised:2025-04-25 Accepted:2025-05-07 Online:2025-08-21 Published:2025-08-28
  • Contact: Xinhui Zhang E-mail:xinhuiz@semi.ac.cn
  • Supported by:
    This work was funded by the National Key Research and Development Program of China (Grant No. 2022YFA1405100) and the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB43000000).

RichHTML

1

PDF (PC)

72

赞

摘要： Transition metal dichalcogenide (TMDC) monolayers provide an ideal platform for exciton and valley-spintronics exploration due to their unique properties. Integrating TMDC monolayers with conventional semiconductors allows for harnessing the unique properties of both materials. This strategy holds great promise for the development of advanced optoelectronics and spintronic devices. In this work, we investigated exciton and valley dynamics in WSe$_{2}$/GaAs heterostructure by employing the femtosecond pump-probe ultrafast spectroscopy. Facilitated by the charge transfer within the heterostructure, it was found that the exciton of WSe$_{2}$ exhibited much longer lifetime of nanosecond than that of the WSe$_{2}$ monolayer counterpart. Especially, a significantly long valley lifetime up to $\sim 2.7 $ ns was observed for trions of WSe$_{2}$ in the heterostructure even under the off-resonant excitation, which is found to be associated with the resident electrons accumulated at the interface resulting from the charge transfer and resultant interfacial electric field. Our results provide fundamental references for conventional semiconductor-integrated TMDC heterostructures that have great potential for designing novel optoelectronic and spintronic devices.

关键词: transition metal dichalcogenide (TMDC) heterostructure, exciton, dynamics, charge transfer, femtosecond time-resolved spectroscopy

Abstract: Transition metal dichalcogenide (TMDC) monolayers provide an ideal platform for exciton and valley-spintronics exploration due to their unique properties. Integrating TMDC monolayers with conventional semiconductors allows for harnessing the unique properties of both materials. This strategy holds great promise for the development of advanced optoelectronics and spintronic devices. In this work, we investigated exciton and valley dynamics in WSe$_{2}$/GaAs heterostructure by employing the femtosecond pump-probe ultrafast spectroscopy. Facilitated by the charge transfer within the heterostructure, it was found that the exciton of WSe$_{2}$ exhibited much longer lifetime of nanosecond than that of the WSe$_{2}$ monolayer counterpart. Especially, a significantly long valley lifetime up to $\sim 2.7 $ ns was observed for trions of WSe$_{2}$ in the heterostructure even under the off-resonant excitation, which is found to be associated with the resident electrons accumulated at the interface resulting from the charge transfer and resultant interfacial electric field. Our results provide fundamental references for conventional semiconductor-integrated TMDC heterostructures that have great potential for designing novel optoelectronic and spintronic devices.

Key words: transition metal dichalcogenide (TMDC) heterostructure, exciton, dynamics, charge transfer, femtosecond time-resolved spectroscopy

中图分类号:  (Spin dynamics)

  • 67.30.hj
31.70.Hq (Time-dependent phenomena: excitation and relaxation processes, and reaction rates) 72.25.Rb (Spin relaxation and scattering) 78.55.-m (Photoluminescence, properties and materials)