Scanning Tunneling Microscopy Study of Epitaxial Growth of Wafer Scale, Single Atomic Sheet Honeycomb BeO Two-dimensional Insulator

ORAL

Abstract

We report the discovery of a novel 2D insulator comprised of a single atomic sheet honeycomb structure BeO, though its bulk counterpart has a wurtzite structure. Such a single sheet of BeO is grown epitaxially on Ag(111) thin films, also epitaxially grown on Si(111) wafers. Using scanning tunneling microscopy and spectroscopy (STM/S) we observe this novel BeO atomic sheet has a lattice constant of 2.65 Å and a band gap of 6 eV. We also found the BeO has a weak van der Waals (vdW) interaction with the Ag(111) substrate, which agrees well with predictions of our density functional theory calculations. Moiré pattern analysis shows the BeO honeycomb structure maintains long range phase coherence in atomic registry even across Ag steps. This novel material provides a scalable platform for 2D electronics, as an attractive 2D insulator due to its potentially much higher thermal conductivity than that of hBN. More significantly, the ability to create a single crystalline atomic sheet with no bulk counterpart of similar structure opens a new avenue toward tailoring novel 2D electronic materials.

*Our research was funded by grants from the Welch Foundation (F-1672), the US National Science Foundation (MRSEC DMR-1720595, EFMA-1542747, DMR-1808751) and the US Airforce (FA2386-18-1-4097).

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Presenters

  • Madisen Holbrook

    • University of Texas at Austin

Authors

  • Madisen Holbrook

    • University of Texas at Austin

  • Hui Zhang

    • University of Science and Technology of China
    • Physics, University of Science and Technology of China

  • Fei Cheng

    • University of Texas at Austin

  • Hyoungdo Nam

    • University of Texas at Austin

  • Mengke Liu

    • University of Texas at Austin

  • Chi-Ruei Pan

    • Physics, Georgia Institute of Technology

  • Damien West

    • Physics, Rensselaer Polytechnic Institute

  • Shengbai Zhang

    • Physics, Rensselaer Polytechnic Institute
    • Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute
    • Rensselaer Polytechnic Institute
    • Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute

  • Mei-Yin Chou

    • Institute of Atomic and Molecular Sciences, Academia Sinica
    • Physics, Georgia Institute of Technology
    • National Taiwan University

  • Chih-Kang Shih

    • Department of Physics, The University of Texas at Austin, Austin, Texas, 78712, USA.
    • University of Texas at Austin
    • Physics, University of Texas at Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States
    • Department of Physics, The University of Texas at Austin
    • Department of Physics, The University of Texas at Austin, USA