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Electric-field-tunable type-I to type-II band transition in MoSe<sub>2</sub>/WS<sub>2</sub> heterobilayer

ORAL

Abstract

We have measured the electric-field-dependent photoluminescence map of a dual-gate MoSe2/ WS2 heterobilayer device encapsulated by boron nitride. At zero electric field, the photoluminescence is dominated by intralayer excitons in the MoSe2 layer, indicating type-I band alignment between MoSe2 and WS2 in the heterobilayer. However, when a strong electric field is applied in the out-of-plane direction, a bright photoluminescence peak appears below the MoSe2 intralayer exciton energy. This new luminescence peak redshifts linearly with increasing electric field, indicating that it arises from interlayer excitons with type-II band alignment. Our results therefore demonstrate that the MoSe2/ WS2 heterobilayer transits from type-I to type-II band alignment under increasing out-of-plane electric field. Such unique electrically controllable band transition may find novel applications in (opto)electronics.




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Presenters

  • Ao Shi

    University of California, Riverside

Authors

  • Ao Shi

    University of California, Riverside

  • Jedediah J Kistner-Morris

    University of California, Riverside

  • Erfu Liu

    University of California, Riverside

  • Takashi Taniguchi

    National Institute for Materials Science, Kyoto Univ, International Center for Materials Nanoarchitectonics, National Institute of Materials Science, Kyoto University, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, National Institute for Materials Science, Japan, National Institute For Materials Science, NIMS, National Institute for Material Science, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan, NIMS Japan

  • Kenji Watanabe

    National Institute for Materials Science, Research Center for Functional Materials, National Institute of Materials Science, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan, NIMS, Research Center for Functional Materials, National Institute for Materials Science, National Institute for Materials Science, Japan, Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan, NIMS Japan

  • Nathaniel M Gabor

    University of California, Riverside

  • Chun Hung Lui

    University of California, Riverside