Visualization of Photo-carrier Diffusion in Monolayer Transition Metal Dichalcogenides

ORAL

Abstract

Understanding of the spatial and temporal evolution of photo-generated charge carriers in atomically thin transition metal dichalcogenides (TMDs) is of critical importance for their application in optoelectronic devices. Using a light-assisted microwave impedance microscope (MIM), we demonstrate the first quantitative mapping of photo-carrier diffusion on monolayer TMDs. When the sample is illuminated by above-gap laser, the circular profile of local photoconductivity measured by the MIM is clearly broader than that of the laser spot. Numerical simulation shows that the free-carrier diffusion length of is on the order of micrometers, corresponding to a carrier lifetime of tens to hundreds of nanoseconds. Our work provides important insights to the remarkable electrical and optical properties of TMDs.

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Presenters

  • Zhaodong Chu

    Department of Physics, The University of Texas at Austin

Authors

  • Zhaodong Chu

    Department of Physics, The University of Texas at Austin

  • Jiamin Quan

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

  • Chun Yuan Wang

    Department of Physics, The University of Texas at Austin, Austin, Texas, 78712, USA., Department of Physics, The University of Texas at Austin, Department of Physics, The University of Texas at Austin, USA

  • David Wannlund

    Department of Physics, The University of Texas at Austin

  • Ali Han

    Physical Sciences and Engineering Division, King Abdullah University of Science and Technology

  • Kevin Herrera

    Department of Physics, The University of Texas at Austin

  • Di Wu

    Department of Physics, The University of Texas at Austin

  • Lain-Jong Li

    Physical Sciences and Engineering, King Abdullah University of Science and Technology, Physical Sciences and Engineering Division, King Abdullah University of Science and Technology

  • Chih-Kang Shih

    Department of Physics, The University of Texas at Austin, Austin, Texas, 78712, USA., University of Texas at Austin, Physics, University of Texas at Austin, Department of Physics, University of Texas at Austin, TX 78712, United States, Department of Physics, The University of Texas at Austin, Department of Physics, The University of Texas at Austin, USA

  • Xiaoqin (Elaine) Li

    University of Texas at Austin, University of Texas-Austin, The University of Texas at Austin, Department of Physics and Center for Complex Quantum Systems, Univ of Texas, Austin, Department of Physics, University of Texas at Austin, TX 78712, United States, Univ of Texas, Austin, Department of Physics, The University of Texas at Austin, Department of Physics, The University of Texas at Austin, USA

  • Keji Lai

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