Depth-resolved imaging of two-dimensional materials via standing-wave photoemission microscopy

ORAL

Abstract

Two-dimensional materials and their heterostructures offer an exciting new avenue for the realization of atomically-thin electronic, photonic, and magnetic devices. This study demonstrates the feasibility of investigating single monolayers of transition-metal dichalcogenides in three dimensions, using depth-resolved standing-wave photoemission microscopy (SW-PEEM) [1,2]. This method is based on excitation with soft x-ray standing waves generated by Bragg reflection from a multilayer (Mo/Si) mirror substrate. Depth-resolved evolution of the WS2 valence-band electronic structure and chemical bonding (via core-level spectromicroscopy) is studied by translating the x-ray standing wave vertically through the substrate and the transferred monolayer. Angstrom-level depth resolution and sensitivity to different depths within the monolayer are demonstrated.

[1] F. Kronast et al., Appl. Phys. Lett. 93, 243116 (2008); [2] A. X. Gray et al., Appl. Phys. Lett. 97, 062503 (2010).

*This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences, and Engineering Division under Award DE-SC0019297.

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Publication: J. R. Paudel, R. Muzzio, H. P. Martins, S. V. Molina, F. Kronast, S. Nemsak, J. Katoch, and A. X. Gray, Depth-resolved imaging of two-dimensional materials via standing-wave photoemission microscopy, in preparation (2022).

Presenters

  • Alex X Gray

    • Temple University
    • Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA

Authors

  • Jay R Paudel

    • Temple University

  • Ryan Muzzio

    • Carnegie Mellon University
    • Carnegie Mellon University, Department of Physics

  • Henrique P Martins

    • Carnegie Mellon University, Advanced Light Source
    • Carnegie Mellon University

  • Sergio V Valencia

    • Helmholtz-Zentrum Berlin
    • Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Germany

  • Florian Kronast

    • Helmholtz-Zentrum Berlin
    • Helmholtz-Zentrum Berlin für Materialien und Energie

  • Slavomir Nemsak

    • Advanced Light Source
    • Lawrence Berkeley National Lab

  • Jyoti Katoch

    • Carnegie Mellon University
    • Carnegie Mellon Univ

  • Alex X Gray

    • Temple University
    • Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA