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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.

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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