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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

  • Masa Ishigami

    Department of Physics, University of Central Florida, Department of Physics and NanoScience Technology Center, University of Central Florida, University of Central Florida

Authors

  • Masa Ishigami

    Department of Physics, University of Central Florida, Department of Physics and NanoScience Technology Center, University of Central Florida, University of Central Florida

  • Stephanie Lough

    University of Central Florida

  • Darian Smalley

    Department of Physics and NanoScience Technology Center, University of Central Florida, University of Central Florida

  • Talat Rahman

    Physics, University of Central Florida, University of Central Florida, Department of Physics, University of Central Florida

  • Duy Le

    Physics, University of Central Florida, University of Central Florida, Department of Physics, University of Central Florida, physics, University of Central Florida

  • Brandon T Blue

    Department of Physics, University of Central Florida, University of Central Florida