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Metallicity of 2H-MoS<sub>2</sub> Induced by Au Hybridization

ORAL

Abstract

The interaction between bulk metal contacts and two-dimensional (2D) transition metal dichalcogenides (TMDs) has a critical influence on overall device performance in a variety of potential applications. This interaction has been studied extensively in the past, especially in the case of moldybdenum disulfide (MoS2), with seemingly contradictory results. In this work, we directly exfoliate monolayer MoS2 onto bulk Au and anneal the resulting heterostructure under ultra-high vacuum (10-10 Torr, UHV) to 450 °C. After annealing, the MoS2 monolayer is observed under scanning tunneling microscopy/spectroscopy (STM/STS) to remain in its 2H lattice configuration, yet with regions ranging from fully gapped to metallic. This observation is corroborated by ex situ Raman and photoemission spectroscopies, which show no signs of the otherwise expected 1T or 1T' structural phase transitions. Theoretical calculations suggest the previous band-gap tuning observed in MoS2-Au heterostructures is due to hybridization and chemical bonding at the S-Au interface, which can completely close the band-gap of 2H-MoS2 at sufficiently short S-Au distances.

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Presenters

  • Brandon Blue

    Physics and Nanoscience Technology Center, University of Central Florida, Physics & Nanoscience Technology Center, University of Central Florida

Authors

  • Brandon Blue

    Physics and Nanoscience Technology Center, University of Central Florida, Physics & Nanoscience Technology Center, University of Central Florida

  • Glenn Jernigan

    Naval Research Laboratory, DC

  • Duy Le

    Univ of Central Florida, Univeristy of Central Florida, Department of Physics, University of Central Florida, University of Central Florida, Physics and Renewable Energy and Chemical Transformations Cluster, University of Central Florida

  • Jose Fonseca

    United States Naval Research Laboratory, Naval Research Laboratory, DC

  • Stephanie Lough

    Physics and Nanoscience Technology Center, University of Central Florida, Physics & Nanoscience Technology Center, University of Central Florida

  • Jesse E Thompson

    Physics and Nanoscience Technology Center, University of Central Florida, Physics & Nanoscience Technology Center, University of Central Florida

  • Darian Smalley

    Physics and Nanoscience Technology Center, University of Central Florida

  • Talat Rahman

    Department of Physics, University of Central Florida, Physics, Univ of Central Florida, University of Central Florida, Physics and Renewable Energy and Chemical Transformations Cluster, University of Central Florida

  • Jeremy Robinson

    United States Naval Research Laboratory, Naval Research Laboratory, DC

  • Masa Ishigami

    Univ of Central Florida, Physics and Nanoscience Technology Center, University of Central Florida, Physics & Nanoscience Technology Center, University of Central Florida