High-Performance WSe<sub>2</sub> Field-Effect Transistors with Accumulation-Type Ohmic Contacts

ORAL

Abstract

We report the creation of accumulation-type ohmic contacts between an intrinsic 2D semiconductor and a degenerately doped 2D semiconductor acting as a 2D metal. Our back-gated WSe2 field-effect transistors (FETs) with bottom-contacts exhibit excellent device performance, including linear output characteristics, a high on/off ratio of 108, and two-terminal extrinsic field-effect mobility approaching the phonon-limited intrinsic mobility. As the temperature decreases, the drain-source current increases while the output characteristics remain linear. Because the back-gate does not electrostatically modulate the intrinsic WSe2 in the drain/source contact regions due to screening by the bottom-contacts, the observed excellent device performance and ohmic behavior can be attributed to the formation of accumulation-type ohmic contacts that are free of a Schottky barrier. The accumulation-type ohmic contacts are further confirmed by dual-gated measurements, where a positive top-gate voltage is applied to deliberately deplete the holes in WSe2 at the drain/source contacts.

*This work was supported by NSF Grant No. DMR-2004445 and Kaskas Scholarship Funds.

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Presenters

  • Zhixian Zhou

    • Wayne State University

Authors

  • Kraig J Andrews

    • Wayne State University

  • Upendra Rijal

    • Wayne State University

  • Arthur Bowman

    • Wayne State University

  • Hsun jen Chuang

    • Wayne State University

  • Jiaqiang Yan

    • Materials Science and Technology Division, Oak Ridge National Lab
    • Oak Ridge National Laboratory
    • University of Tennessee
    • Oak Ridge National Lab
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Materials Science and Technology, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory, Materials Science and Technology Division

  • David George Mandrus

    • Materials Science and Technology Division, Oak Ridge National Labratory
    • Materials Science and Engineering, University of Tennessee
    • Department of Materials Science and Engineering, University of Tennessee
    • University of Tennessee
    • Department of Materials Science and Engineering, University of Tennessee Knoxville
    • Department of Materials Science & Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
    • Oakridge National Laboratory
    • Materials Science and Engineering, University of Tennessee, Knoxville
    • Oak Ridge National Laboratory
    • University of Tennessee - Knoxville
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Department of Physics, University of Tennessee Knoxville
    • Materials Science and Technology, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory, Materials Science and Technology Division
    • Department of Materials Science, The University of Tennessee
    • University of Tennessee, Knoxville

  • Zhixian Zhou

    • Wayne State University