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