Twist-Angle Dependent Interlayer Exciton Emission in MoSe2-WSe2 Heterostructures

ORAL

Abstract

Two-dimension materials can be stacked together to realize van der Waals heterostructures that host novel optical and electronic properties. By stacking two different transition metal dichalcogenide semiconductors together, interlayer excitons (IXs) can be realized, which are composed of electrons and holes located in different layers. Recent studies in MoSe2-WSe2 heterostructures have shown bright IX photoluminescence (PL) when the twist-angle between layers is close to 0 (R-type stacking) or 60 (H-type stacking). Previously it has been shown that R and H type heterostructures exhibit twist-angle dependent polarization properties due to the valley dependent optical selection rules. In this presentation, I will discuss several significant differences between the optical response of R-type and H-type hBN encapsulated MoSe2-WSe2 heterostructures.I will show that the two types of heterostructures (R and H) exhibit qualitatively different dependencies of PL intensity as a function of temperature and excitation power. Time resolved PL measurements further distinguish R and H type IXs, where the latter exhibits a density dependent lifetime which we attribute to intervalley scattering.

*Acknowledgements: We acknowledge funding from NSF Grants: DMR-1838378, DMR-2003583, and ECCS-1708562.

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Presenters

  • Fateme Mahdikhanysarvejahany

    • Department of Physics, University of Arizona
    • University of Arizona

Authors

  • Fateme Mahdikhanysarvejahany

    • Department of Physics, University of Arizona
    • University of Arizona

  • Michael R Koehler

    • JIAM Diffraction Facility, Joint Institue for Advanced Materials, University of Tennessee
    • Joint Institute for Advanced Materials Diffraction Facility, University of Tennessee
    • The University of Tennessee

  • David George Mandrus

    • Materials Science and Technology Division, Oak Ridge National Labratory
    • Materials Science and Engineering, University of Tennessee
    • Department of Materials Science and Engineering, University of Tennessee
    • University of Tennessee
    • Department of Materials Science and Engineering, University of Tennessee Knoxville
    • Department of Materials Science & Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
    • Oakridge National Laboratory
    • Materials Science and Engineering, University of Tennessee, Knoxville
    • Oak Ridge National Laboratory
    • University of Tennessee - Knoxville
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Department of Physics, University of Tennessee Knoxville
    • Materials Science and Technology, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory, Materials Science and Technology Division
    • Department of Materials Science, The University of Tennessee
    • University of Tennessee, Knoxville

  • Takashi Taniguchi

    • National Institute for Materials Science, Japan
    • National Institute for Materials Science
    • Department of Chemical Engineering, Kyoto University
    • National Institute for Materials Science, Tsukuba, Ibaraki, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • Materials, NIMS
    • International Center for Materials Anorthite, National Institute for Materials Science, Ibaraki, Japan
    • Kyoto University

  • Kenji Watanabe

    • National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • National Institure for Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science
    • NIMS
    • National Institute of Materials Science
    • National Institute for Materials Science (NIMS)
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute for Materials Science,1-1 Namiki
    • National Institute of Material Science
    • National Institute for Materials Science, Tsukuba, Japan
    • Research Center for Functional Materials, NIMS
    • National Institute of Materials Science, Tsukuba, Japan
    • National Institude for Materials Science
    • National Institute for Materials Science, Tsukuba, Ibaraki, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, Tsukuba 305-0044, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Materials
    • NIMS - Japan
    • National Institute for Materials Science ,Japan
    • National Institute for Materials Science, Tsukuba, 305-0044, Ibaraki, Japan
    • National Institute for Material Science
    • National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science Japan
    • NIMS Tsukuba
    • National Institute for Materials Science, Research Center for Functional Materials, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Materials Science: Namiki, Tsukuba, Ibaraki, JP
    • National Institue for Material Science
    • National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan
    • Materials, NIMS
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, Research Center for Functional Materials, National In
    • Research Center for Functional Materials, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • International Center for Materials nanoarchtectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
    • NIMS Suguba
    • NIMS, Tsukuba, Japan
    • National Institute for Materials Science, Namiki 1-1, Tsukuba, 305-0044, Ibaraki, Japan
    • National institute of material science
    • Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
    • Advanced Materials Laboratory, NIMS
    • Research Center for Functional Materials, National Institute for Materials Science, Ibaraki, Japan
    • National Institute for Materials Science, Research Center for Functional Materials
    • National Institute of Material Science, Japan
    • Tsukuba, National Institute for Materials Science

  • Oliver L.A. Monti

    • Chemistry & Biochemistry, University of Arizona
    • University of Arizona

  • Brian J LeRoy

    • Physics, University of Arizona
    • Department of Physics, University of Arizona
    • Physics, University of Arizona, Tucson AZ
    • University of Arizona

  • John Schaibley

    • Department of Physics, University of Arizona
    • Physics, University of Arizona
    • University of Arizona