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

Junho Choi; Wei-Ting Hsu; Li-Shuan Lu; Hui-Yu Cheng; Liuyang Sun; Kha Tran; André Zepeda; Marshall Campbell; Matthew Staab; Kayleigh R Jones; Takashi Taniguchi; Kenji Watanabe; Chih-Kang Shih; Xiaoqin (Elaine) Li; Wen-Hao Chang

Interlayer exciton diffusion in MoSe₂/WSe₂ 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.

March 4, 2019, 3:42 PM – March 4, 2019, 3:54 PM

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