Low work-function contact engineering for transition metal dichalcogenides (TMDs)

ORAL

Abstract

Atomically thin transition metal dichalcogenides (TMDs) are an exciting platform to study strongly correlated excitonic and electronic physics. However, electrical transport measurements in monolayer TMDs are limited by the ability to fabricate reliable electrodes, particularly n-type contacts to MoSe2, MoS2, and MoTe2, due to Schottky barrier formation and metal-induced gap states. Efficient n-type contacts to these materials typically require work-function matching at the metal-semiconductor interface and heavy electron doping. Inspired by recent advances in p-type contacts to WSe2 by RuCl3 van der Waals ‘modulation’ doping, we investigate interfacing TMDs with very low work-function metals to explore interfacial charge transfer. These efforts can be combined with an atomically clean monolayer hBN insertion barrier between the metal-semiconductor interface that has been demonstrated to lower the metal work function and reduce in-gap states. We present electrical transport measurements to characterize the performance of these contacts to TMDs such as MoSe2 and MoS2.

*NSF Graduate Research Fellowships Program (GRFP)

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Presenters

  • Grace Chen

    • Harvard University

Authors

  • Grace Chen

    • Harvard University

  • Andres M Mier Valdivia

    • Harvard University

  • Nadine Leisgang

    • Harvard University

  • Sungpyo Baek

    • SKKU

  • Seong-Jun Yang

    • Pohang University of Science and Technology

  • Kenji Watanabe

    • National Institute for Materials Science
    • NIMS
    • Research Center for Electronic and Optical Materials, National Institute for Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science

  • Takashi Taniguchi

    • Kyoto Univ
    • National Institute for Materials Science
    • Research Center for Materials Nanoarchitectonics
    • Research Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • National Institute for Materials Sciences
    • NIMS
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science
    • International Center for Materials Nanoarchitectonics, NIMS, Japan
    • International Center for Materials Nanoarchitectonics, Tsukuba
    • National Institue for Materials Science
    • Kyoto University
    • National Institute of Materials Science
    • International Center for Materials Nanoarchitectonics and National Institute for Materials Science

  • Cheol-Joo Kim

    • Pohang University of Science and Technology

  • Sungjoo Lee

    • SKKU

  • Philip Kim

    • Harvard University