Excitonic Complexes in a Charge Tunable WSe2 Monolayer Device

ORAL

Abstract

Transition Metal Dichalcogenides (TMD) monolayers have emerged as exciting 2D materials for optoelectronics and spintronics. Due to the large exciton binding energies and strong spin-orbit coupling, these materials can host various and robust excitonic complexes. The encapsulation of TMD monolayers into hBN combined with the constant improvement of the material quality now enable to reproducibly observe and control these excitonic complexes in the optical spectra.
In this work, we study a WSe2 monolayer embedded into a charge tunable device made of graphite electrodes and hBN. This allows us to study excitonic complexes in different doping regimes (neutral, n or p). We systematically performed magneto-photoluminescence/reflectivity and time resolved photoluminescence as a function of doping to identify the nature of the excitonic transitions based on their characteristic Landé g-factor and their temporal dynamics. The fine structure of the trion (intervalley, intravalley, dark trion) will first be discussed. Phonon assisted transitions (momentum mismatch dark exciton and spin forbidden dark exciton) are also identified. Finally the origin of more complex transitions observed under high n type doping will be discussed.

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Presenters

  • Xavier Marie

    • CNRS/INSA
    • Institut National des Sciences Appliquees de Toulouse
    • INSA-Toulouse
    • LPCNO, University of Toulouse

Authors

  • Cédric Robert

    • Institut National des Sciences Appliquees de Toulouse
    • LPCNO, University of Toulouse

  • Emmanuel Courtade

    • INSA-Toulouse
    • LPCNO, University of Toulouse
    • Institut National des Sciences Appliquees de Toulouse

  • Delphine Lagarde

    • LPCNO, University of Toulouse
    • Institut National des Sciences Appliquees de Toulouse

  • Takashi Taniguchi

    • National Institute for Materials Science, Japan
    • National Institute for Material Science
    • National Institute for Materials Science
    • National Institute for Materials Science, Tsukuba
    • Research Center for Functional Materials, NIMS
    • nims
    • Advanced Materials Laboratory, National Institute for Materials Science
    • National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • NIMS
    • National Institute for Material Science - Japan
    • NIMS Tsukuba
    • National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan.
    • National Institute for Materials Science (NIMS)
    • National Institute for Materials Science,Tsukuba, Ibaraki 305-0047, Japan
    • Advanced Materials Laboratory, NIMS, Japan
    • National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan
    • National Institute of Materials Science
    • National Institute for Materials Science, University of Tsukuba
    • National Institute for Materials Science, Tsukuba, Japan
    • National Institue for Material Science, Tsukuba
    • Advanced Materials Laboratory, NIMS
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba 305-0044, Japan
    • Advanced Matrials Lab, NIMS
    • National Institute for Material Science, Tsukuba, Japan
    • National institute for materials science
    • NIMS-Tsukuba
    • NIMS, Japan
    • National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan
    • National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
    • Advanced Materials Laboratory, National Institute of Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science 1-1 Namiki, Tsukuba, 305-0044, Japan
    • National Institute of Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science (Japan)
    • Physics, NIMS
    • National Institute of Materials Science, Japan
    • National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • NIMS - Tsukuba

  • Kenji Watanabe

    • National Institute for Materials Science, Japan
    • National Institute for Material Science
    • National Institute for Materials Science
    • National Institute for Materials Science, Tsukuba
    • Research Center for Functional Materials, NIMS
    • nims
    • Advanced Materials Laboratory, National Institute for Materials Science
    • National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • NIMS
    • National Institute for Material Science - Japan
    • NIMS Tsukuba
    • National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan.
    • National Institute for Materials Science (NIMS)
    • National Institute for Materials Science,Tsukuba, Ibaraki 305-0047, Japan
    • Advanced Materials Laboratory, NIMS, Japan
    • National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan
    • National Institute of Materials Science
    • National Institute for Materials Science, University of Tsukuba
    • National Institute for Materials Science, Tsukuba, Japan
    • National Institute for Material Science, Japan
    • National Institue for Material Science, Tsukuba
    • Advanced Materials Laboratory, NIMS
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba 305-0044, Japan
    • Advanced Matrials Lab, NIMS
    • National Institute for Material Science, Tsukuba, Japan
    • National institute for materials science
    • NIMS-Tsukuba
    • NIMS, Japan
    • National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan
    • NIRM
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan
    • National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
    • Advanced Materials Laboratory, National Institute of Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science 1-1 Namiki, Tsukuba, 305-0044, Japan
    • National Institute of Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science (Japan)
    • Physics, NIMS
    • National Institute of Materials Science, Japan
    • National Institute of Materials Science (NIMS)
    • National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • NIMS - Tsukuba

  • Bernhard Urbaszek

    • CNRS/INSA
    • Institut National des Sciences Appliquees de Toulouse
    • INSA-Toulouse
    • LPCNO, University of Toulouse

  • Thierry Amand

    • LPCNO, University of Toulouse
    • Institut National des Sciences Appliquees de Toulouse

  • Xavier Marie

    • CNRS/INSA
    • Institut National des Sciences Appliquees de Toulouse
    • INSA-Toulouse
    • LPCNO, University of Toulouse