Study of momentum-resolved exciton and free carrier properties in monolayer WS<sub>2</sub>

ORAL

Abstract

2D semiconductors, such as monolayer transition metal dichalcogenides (TMDCs), have drawn significant attention owing to their unique electrical and optical properties. Despite this attention, much remains to be known about the excited states of these materials in momentum space. Recently, time- and angle- resolved photoemission spectroscopy (TR-ARPES) has been successfully applied to provide a momentum space prospective of the excitonic states in WSe2 monolayer and multilayered heterostructures 1-3. Here we simultaneously access both the excitons and free carriers in monolayer WS2 across the entire first Brillouin zone. Thereby, we provide a direct measurement of the excited state properties, which critically determine the optoelectronic properties of 2D semiconductors.

[1] Madéo, J. et al. Directly visualizing the momentum-forbidden dark excitons and their dynamics in atomically thin semiconductors. Science 370, 1199-1204, 2020.

[2] Man, M. K. L. et al. Experimental measurement of the intrinsic excitonic wave function. Sci. Adv. 7, eabg0192, 2021.

[3] Karni, O. et al. Structure of the moiré exciton captured by imaging its electron and hole. Nature 603, 247-252, 2022.

*funding from the Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University

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Presenters

  • Xing Zhu

    • Okinawa Institute of Science and Technology

Authors

  • Xing Zhu

    • Okinawa Institute of Science and Technology

  • David R Bacon

    • Okinawa institute of science and technology
    • Okinawa Institute of Science and Technology

  • Vivek Pareek

    • Okinawa Institute of Science & Technology
    • Okinawa Institute of Science and Technology

  • Joel P Urquizo

    • Okinawa Insitute of Science and Technology
    • Okinawa Institute of Science and Technology

  • Nicholas S Chan

    • Okinawa Institute of Science & Technology
    • Okinawa Institute of Science and Technology

  • Fabio Bussolotti

    • Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR)

  • 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

  • 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

  • Michael K Man

    • Okinawa Institute of Science and Technology

  • Julien Madéo

    • Okinawa Insitute of Science and Technology
    • Okinawa Institute of Science and Technology

  • Kuan Eng Johnson Goh

    • Department of Physics, National University of Singapore; Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR)
    • IMRE, A*STAR, Department of Physics, NUS, Division of Physics and Applied Physics, NTU

  • Keshav M Dani

    • Okinawa Institute of Science & Technology
    • Okinawa Institute of Science and Technology