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Momentum resolved ground/excited states and the ultra-fast excited state dynamics of monolayer MoS<sub>2</sub>

ORAL

Abstract

The emergence of transition metal dichalcogenides (TMD) as crystalline atomically thin semiconductors has created a tremendous amount of scientific and technological interest. Many novel device concepts have been proposed and realized. Nonetheless, progress in k-space investigations of ground/excited state electronic structures has been slow due to the challenge to create large scale, laterally homogeneous samples. Taking advantage of recent advancements in chemical vapor deposition, here we create a wafer-size MoS2 monolayer with well-aligned lateral orientation. The ground state and excited state electronic structures are probed using scanning tunneling spectroscopy (STS), angle-resolved photoemission (ARPES) and time-resolved (tr-)ARPES. In addition to mapping out the momentum-space quasiparticle band structure in the valence and conduction bands, we unveil ultrafast excited state dynamics, including inter- and intra-valley carrier scattering and a rapid downward energy shift by ~ 0.2eV lower than the initial free carrier state at sigma point.

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Presenters

  • Woojoo Lee

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

Authors

  • Woojoo Lee

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

  • Yi Lin

    Materials Sciences Division, Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, Materials Science Division, Lawrence Berkeley National Laboratory

  • Li-Syuan Lu

    Department of Electrophysics, National Chiao Tung University, Electrophysics, National Chiao Tung University

  • Wei-Chen Chueh

    Electrophysics, National Chiao Tung University

  • Mengke Liu

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

  • Xiaoqin (Elaine) Li

    University of Texas at Austin, Physics, University of Texas at Austin, Department of Physics, University of Texas at Austin, U.T. Austin, Department of Physics, The University of Texas at Austin, Department of Physics, Center of Complex Quantum Systems, University of Texas at Austin

  • Wen-Hao Chang

    Department of Electrophysics, National Chiao Tung University, Electrophysics, National Chiao Tung University, Natl Chiao Tung Univ

  • Robert A Kaindl

    Materials Sciences Division, Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, Department of Physics, Arizona State University, Physics, Arizona State University

  • Chih-Kang Shih

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