Mapping Electric Fields in Twisted WSe<sub>2</sub> Ferroelectrics

ORAL

Abstract

Moiré superlattice systems formed by stacking two or more van der Waals materials can be used to create devices with unique electronic and optical properties. With atomic-scale thicknesses, such devices are ideal for study with scanning transmission electron microscopy (STEM). Unfortunately, while STEM can reveal physical structure with high resolution, it struggles to visualize electronic properties. Here, we use STEM to image capacitors consisting of twisted WSe2 encapsulated by graphite electrodes and hBN. The devices exhibit sliding moiré ferroelectricity that we switch in situ. We map the local electric fields using STEM electron beam-induced current (EBIC) imaging, which gives a picture of the device that complements the one determined by 4D STEM.

*This work was supported by National Science Foundation (NSF) award DMR-2004897 and NSF Science and Technology Center (STC) award DMR-1548924 (STROBE).

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Presenters

  • Tristan O'Neill

    • University of California, Los Angeles

Authors

  • Tristan O'Neill

    • University of California, Los Angeles

  • Yueyun Chen

    • University of California, Los Angeles

  • Ho Leung Chan

    • University of California, Los Angeles

  • Madeline Van Winkle

    • University of California, Berkeley

  • Kwabena Bediako

    • University of California Berkeley

  • Brian Christopher Regan

    • University of California, Los Angeles