Spatiotemporal Microwave Imaging of Photo-carrier Dynamics in Monolayer Semiconductors

ORAL

Abstract

The spatiotemporal evolution of photo-generated charge carriers in two-dimensional transition-metal dichalcogenides (TMDs) plays a crucial role for their optoelectronic applications. A comprehensive understanding of such dynamics, however, remains a challenging task. Here, we report the simultaneous spatial and temporal photoconductivity imaging in WS2 monolayers by laser-illuminated microwave impedance microscopy. The diffusion length and carrier lifetime were directly measured. Time-resolved experiments indicate that the critical process for photo-carriers is the escape of holes from defect-induced trap states, which prolong the apparent lifetime of mobile electrons in the conduction band. This work provides fundamental knowledge on the defect-mediated spatiotemporal dynamics of charge carriers in 2D TMDs, paving the way for their applications in novel optoelectronic devices.

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Presenters

  • Zhaodong Chu

    • University of Texas at Austin

Authors

  • Zhaodong Chu

    • University of Texas at Austin

  • Chun Yuan Wang

    • Physics, University of Texas at Austin
    • University of Texas at Austin

  • Jiamin Quan

    • Physics, University of Texas at Austin
    • Department of Physics, The University of Texas at Austin
    • University of Texas at Austin
    • Department of Physics, Complex Quantum Systems, and Texas Materials Institutes, University of Texas at Austin

  • Chenhui Zhang

    • King Abdullah University of Science and Technology
    • King Abdullah Univ of Sci & Tech (KAUST)

  • Chao Lei

    • University of Texas at Austin

  • Ali Han

    • King Abdullah University of Science and Technology

  • Xuejian Ma

    • University of Texas at Austin

  • Hao-Ling Tang

    • King Abdullah University of Science and Technology

  • Dishan Abeysinghe

    • University of Texas at Austin

  • Matthew Staab

    • University of Texas at Austin

  • Xixiang Zhang

    • King Abdullah University of Science and Technology
    • King Abdullah Univ of Sci & Tech (KAUST)

  • Allan MacDonald

    • University of Texas at Austin
    • Physics, University of Texas at Austin
    • Department of Physics, University of Texas at Austin
    • Department of Physics, The University of Texas at Austin

  • vincent Tung

    • King Abdullah University of Science and Technology

  • Chih-Kang Shih

    • University of Texas at Austin
    • Physics, University of Texas at Austin
    • Department of Physics, The University of Texas at Austin

  • Xiaoqin (Elaine) Li

    • Physics, University of Texas at Austin
    • Department of Physics, The University of Texas at Austin
    • Department of Physics, University of Texas at Austin
    • University of Texas at Austin
    • Department of Physics, Complex Quantum Systems, and Texas Materials Institutes, University of Texas at Austin

  • Keji Lai

    • University of Texas at Austin