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Nano Research

Article Title

Salt-assisted growth and ultrafast photocarrier dynamics of large-sized monolayer ReSe2

Authors

Shaolong Jiang, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
Jin Yang, Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China University of Science and Technology of China, Hefei 230026, China
Yuping Shi, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
Jing Zhao, Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China University of Science and Technology of China, Hefei 230026, China
Chunyu Xie, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
Liyun Zhao, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
Jiatian Fu, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
Pengfei Yang, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
Yahuan Huan, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
Qin Xie, Center for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
Huachao Jiang, Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
Qing Zhang, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
Xianlong Wang, Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
Fuhai Su, Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
Yanfeng Zhang, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China

Keywords

ReSe2, chemical vapor deposition, sodium chloride, large size, ultrafast photocarrier dynamics

Abstract

Owing to its anisotropic optical and electrical properties, rhenium diselenide (ReSe2) has garnered considerable attention recently as a candidate material for polarization-sensitive photodetectors. However, the direct and controllable synthesis of large-sized ReSe2 with a uniform thickness is still a great challenge. Herein, we have refined the synthesis method to obtain uniform monolayer ReSe2 flakes with a size of up to ~ 106 μm on sapphire via an ambient-pressure chemical vapor deposition technique using Na promoter from sodium chloride. Interestingly, optical pump-probe spectroscopy revealed a fast switching from saturable absorption (SA) to absorption enhancement (AE) in subpicosecond time scale, followed by a slower decay induced by exciton recombination. Furthermore, both AE and SA signals exhibited clear angular dependence with a periodicity of 180°, which reflected the dichroism in nonlinear absorption dynamics. In addition, the photocarrier dynamics including free-carrier transport and subpicosecond relaxation due to exciton formation or surface trapping was probed using time resolved terahertz spectroscopy. We believe that our study serves as a reference for atomically controlled synthesis of large-sized ReSe2 and provides useful insights on its optoelectronic properties for novel device applications.

Graphical Abstract

Publisher

Tsinghua University Press

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