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High Mobility <i>n</i>-type Field-Effect Transistors Based on WSe<sub>2</sub>/PdSe<sub>2 </sub>Heterostructures

ORAL

Abstract

Recently, group-10 transition metal dichalcogenides (TMDs) such as PtSe2 and PdSe2 have emerged as 2D materials with a theoretically predicted electron mobility significantly higher than that of group-6 TMDs. However the performance of field-effect transistors (FETs) based on few-layer PdSe2 has been limited by the presence of a Schottky barrier at the drain/source contacts. In this work, we utilize a 2D-semiconductor interlayer at the metal/PdSe2 contacts to significantly lower the Schottky barrier. As a result, our FETs based on PdSe2/WSe2 heterostructures exhibit a two-terminal effective mobility exceeding 200 cm2 V-1 s-1 at room temperature and approaching 700 cm2 V-1 s-1 at 77 K, consistent with phonon-limited electron transport. By contrast, the two-terminal effective mobility of FETs based on few-layer PdSe2 (without WSe2) decreases with decreasing temperature, suggesting that the electron transport is limited by the contacts. Our PdSe2/WSe2 heterostructure FET consisting of a trilayer PdSe2 and a bilayer WSe2 concurrently exhibits a high ON/OFF ratio of ~ 107 and significantly enhanced two-terminal electron mobility compared to FETs based on a trilayer PdSe2 or a bilayer WSe2 alone.

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Presenters

  • Arthur Bowman

    Wayne State University

Authors

  • Arthur Bowman

    Wayne State University

  • Kraig J Andrews

    Wayne State University

  • Amanda Haglund

    University of Tennessee, Materials Science and Engineering, The University of Tennessee

  • 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