Interlayer exciton diffusion in MoSe<sub>2</sub>/WSe<sub>2</sub> heterostructures

ORAL

Abstract

Excitons with large binding energy are formed in atomically thin semiconductors because of the insufficient dielectric screening outside of the 2D layers. In a vertical heterostructure consisting of MoSe2 and WSe2 monolayers, the type-II band alignment leads to the rapid transfer of electron to the MoSe2 layer and hole to the WSe2 layer, forming interlayer excitons with drastically different properties than excitons confined within one monolayer. We investigate the interlayer exciton diffusion in MoSe2/WSe2 heterostructures. We compare a mechanically stacked heterostructure with hexagonal boron nitride (hBN) encapsulation and one grown by chemical vapor deposition (CVD). Spatially and time-resolved photoluminescence measurements are performed at low-temperature. Interlayer exciton diffusion length and coefficient are extracted in both heterostructures and found to be rather different.

*We gratefully acknowledge funding from NSF MRSEC program DMR-1720595, NSF DMR-1808042, EFMA-1542747, and Welch Foundation F-1662.

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Presenters

  • Junho Choi

    • University of Texas at Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States

Authors

  • Junho Choi

    • University of Texas at Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States

  • Wei-Ting Hsu

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

  • Li-Shuan Lu

    • Electrophysics, National Chiao Tung University
    • Department of Electrophysics, National Chiao Tung University
    • Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan
    • Department of Electrophysics, National Chiao Tung University, Taiwan

  • Hui-Yu Cheng

    • Department of Electrophysics, National Chiao Tung University,
    • Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan

  • Liuyang Sun

    • Department of Physics, University of Texas at Austin, TX 78712, United States

  • Kha Tran

    • University of Texas at Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States

  • André Zepeda

    • University of Texas at Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States

  • Marshall Campbell

    • University of Texas at Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States

  • Matthew Staab

    • Department of Physics, University of Texas at Austin, TX 78712, United States

  • Kayleigh R Jones

    • Department of Physics, University of Texas at Austin, TX 78712, United States

  • Takashi Taniguchi

    • National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305 0044, Japan
    • National Institute for Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science, , 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044
    • National Institute of Materials Science
    • NIMS, Japan
    • Advanced Materials Laboratory, NIMS
    • National Institute for Materials Science, Tsukuba, Japan
    • Advanced Materials Laboratory, National Institute for Materials Science
    • National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute for Materials Science (NIMS)
    • NIMS Tsukuba
    • NIMS
    • National Institute for Material Science
    • National Institute for Materials Science, Japan
    • National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan
    • National Institute for Materials Science , Japan
    • Advanced Materials Laboratory, National Institute for Materials Science, Japan
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute for Materials Science, Tsukuba, Ibaraki 305- 0044, Japan
    • National Institute for Material Science - Japan
    • National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan
    • National Institute of Material Science
    • Advanced Material Lab, NIMS
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
    • National Institute for Materials Science, Tsukuba
    • 1-1 Namiki, Tsukuba, National Institute for Materials Science
    • NIMS/Tsukuba
    • National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044 Japan
    • National Institute for Materials Science, Namiki, 305-0044, Japan
    • National Institute for Material Science, Japan
    • Advanced Materials Laboratory, NIMS, Japan
    • Advanced Materials Labaratory, National Institute for Materials Science
    • National Institute of Material Science, 1-1 Namiki, Tsukuba, Ibaraki 205-0044, Japan
    • National Institute of Materials Science, Japan

  • Kenji Watanabe

    • National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305 0044, Japan
    • Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science, , 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044
    • National Institute of Materials Science
    • NIMS, Japan
    • Advanced Materials Laboratory, NIMS
    • National Institute for Materials Science, Tsukuba, Japan
    • National Institute for Materials Science, Japan
    • Advanced Materials Laboratory, National Institute for Materials Science
    • National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute for Materials Science (NIMS)
    • NIMS Tsukuba
    • National Institute for Materials Science (Japan)
    • NIMS
    • National Institute for Material Science
    • National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan
    • National Institute for Materials Science , Japan
    • National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan.
    • Advanced Materials Laboratory, National Institute for Materials Science, Japan
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • National Institute for Materials Science, Tsukuba, Ibaraki 305- 0044, Japan
    • National Institute for Material Science - Japan
    • National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan
    • National Institute of Material Science
    • Advanced Material Lab, NIMS
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
    • National Institute for Materials Science, Tsukuba
    • 1-1 Namiki, Tsukuba, National Institute for Materials Science
    • NIMS/Tsukuba
    • National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044 Japan
    • National Institute for Materials Science, Namiki, 305-0044, Japan
    • National Institute for Material Science, Japan
    • Advanced Materials Laboratory, NIMS, Japan
    • Columbia University
    • Advanced Materials Labaratory, National Institute for Materials Science
    • National Institute of Material Science, 1-1 Namiki, Tsukuba, Ibaraki 205-0044, Japan
    • National Institute of Materials Science, Japan

  • 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

  • Wen-Hao Chang

    • Electrophysics, National Chiao Tung University
    • Department of Electrophysics, National Chiao Tung University
    • Department of Electrophysics, National Chiao Tung University,
    • Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan
    • Department of Electrophysics, National Chiao Tung University, Taiwan