2D materials under the microscope(s)

ORAL

Abstract

Interest in transition metal dichalcogenides (TMDs) has been renewed by the discovery of emergent properties when reduced to single, two-dimensional (2D) layers. Here, we use a set of complementary techniques - photoluminescence, Kelvin probe, scanning tunneling and photoelectron spectroscopy – to correlate locally chemical state, electronic structure, and optical properties of 2D-TMDs. Atomic force and scanning tunneling microscopy allowed us to identify unambiguously the atomic and electronic structure of chalcogen and metal vacancies in chemical vapor deposition grown WS2. Furthermore, we employ spatially and angle resolved photoemission spectroscopy (nano-ARPES) to map variations in band alignment and chemical composition. By correlating this information with photoluminescence data, we reveal the interplay between local material properties, such as defect density or chemical composition, and the formation of charged trions, defect-bound excitons and neutral excitons.

*Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under Contract No. DE-AC02-05CH11231. This research used resources of the Advanced Light Source, which is a DOE Office of Science User Facility under contract no. DE-AC02-

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Presenters

  • Christoph Kastl

    • Lawrence Berkeley National Laboratory
    • The Molecular Foundry, Lawrence Berkeley National Laboratory
    • Molecular Foundry, Lawrence Berkeley National Laboratory

Authors

  • Christoph Kastl

    • Lawrence Berkeley National Laboratory
    • The Molecular Foundry, Lawrence Berkeley National Laboratory
    • Molecular Foundry, Lawrence Berkeley National Laboratory

  • Roland Koch

    • Lawrence Berkeley Natl Lab
    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Lab
    • Naval Research laboratory

  • Christopher Chen

    • Lawrence Berkeley National Laboratory
    • Molecular Foundry, Lawrence Berkeley National Laboratory

  • Bruno Schuler

    • Lawrence Berkeley National Laboratory

  • Johanna Eichhorn

    • Lawrence Berkeley National Laboratory
    • Chemical Sciences Division, Lawrence Berkeley National Laboratory

  • Simon Moser

    • Lawrence Berkeley Natl Lab
    • Lawrence Berkeley National Laboratory
    • Advanced Light Source, Lawrence Berkeley National Laboratory

  • Søren Ulstrup

    • Lawrence Berkeley Natl Lab
    • Lawrence Berkeley National Laboratory
    • Aarhus University
    • Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University

  • Tevye Kuykendall

    • Lawrence Berkeley National Laboratory
    • Molecular Foundry, Lawrence Berkeley National Laboratory

  • Aaron Bostwick

    • Advanced light source
    • Lawrence Berkeley Natl Lab
    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Lab
    • Advanced Light Source, Lawrence Berkeley National Laboratory

  • Chris Jozwiak

    • Advanced light source
    • Lawrence Berkeley Natl Lab
    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Lab
    • Advanced Light Source, Lawrence Berkeley National Laboratory

  • Eli Rotenberg

    • Advanced light source
    • Lawrence Berkeley Natl Lab
    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Lab
    • Advanced Light Source, Lawrence Berkeley National Laboratory

  • Alexander Weber-Bargioni

    • Lawrence Berkeley National Laboratory
    • Molecular Foundry, Lawrence Berkeley National Laboratory

  • Shaul Aloni

    • Lawrence Berkeley National Lab
    • Lawrence Berkeley National Laboratory
    • Molecular Foundry, Lawrence Berkeley National Laboratory
    • Molecular Foundry, Lawrence Berkeley National Lab

  • Adam Schwartzberg

    • Lawrence Berkeley National Laboratory
    • The Molecular Foundry, Lawrence Berkeley National Laboratory
    • Molecular Foundry, Lawrence Berkeley National Laboratory