Bandgap Tuning for Monolayer TMD Materials by Using STM Tip

ORAL

Abstract

Monolayer transition metal dichalcogenides (TMDs) offer a promising platform for developing advanced electronics beyond graphene. Similar to two-dimensional molecular frameworks, the electronic properties of such monolayers can be sensitive to perturbations from the surroundings; the implied tunability of electronic structure is of great interest. Using scanning tunneling microscopy/spectroscopy, we demonstrated a bandgap engineering technique in two monolayer materials, MoS2 and PtTe2, with the tunneling current as a control parameter [1]. The bandgap of monolayer MoS2 decreases logarithmically by the increasing tunneling current, indicating an electric-field-induced gap renormalization effect. Monolayer PtTe2, by contrast, exhibits a much stronger gap reduction, and a reversible semiconductor-to-metal transition occurs at a moderate tunneling current. This unusual switching behavior of monolayer PtTe2, not seen in bulk semimetallic PtTe2, can be attributed to its surface electronic structure that can readily couple to the tunneling tip, as demonstrated by theoretical calculations. Our findings reported herein have significant implications regarding methods and the principles for bandgap engineering of TMD monolayers.

*The authors gratefully acknowledge financial support from the “Center for the Semiconductor Technology Research” from The Featured Areas Research Center Program within theframework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan and the National Science and Technology Council (NSTC) of Taiwan under Grants Nos. NSTC 110-2634-F-009-027, NSTC 110-2112-M-008-039-MY3, NSTC 110-2112-M-A49-013-MY3, NSTC 110-2112-M-A49-022-MY2, NSTC 109-2112-M-006-013,-, NSTC 110-2124-M-006-006, NSTC 110-2124-M-006-010, NSTC 107-2112-M-003-011, and NSTC 111-2119-M-A49-005-MBK.the Ministry of Education, Culture, Sports, Science and Technology, Japan,under Grant MEXT KAKENHI, Grants 22H01960 and 22K05326. the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Materials Science and Engineering, under Grant No. DE-FG02-07ER46383.

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Presenters

  • Chun-Liang Lin

    • Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
    • National Yang Ming Chiao Tung University

Authors

  • Chun-Liang Lin

    • Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
    • National Yang Ming Chiao Tung University

  • Guan-Hao Chen

    • Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
    • National Yang Ming Chiao Tung University

  • Meng-Kai Lin

    • National Central University

  • Joseph A Hlevyack

    • University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Champai

  • Chia-Nung Kuo

    • National Cheng Kung University
    • Department of Physics, National Cheng Kung University, Tainan, Taiwan
    • Department of Physics, National Cheng Kung University

  • Tsu-Yi Fu

    • National Taiwan Normal University

  • Juhn-Jong Lin

    • Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
    • National Yang Ming Chiao Tung University

  • Chin Shuan Lue

    • National Cheng Kung University
    • Department of Physics, National Cheng Kung University, Tainan, Taiwan

  • Wen-Hao Chang

    • Academia Sinica
    • Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
    • National Yang Ming Chiao Tung University

  • Noriaki Takagi

    • Kyoto University

  • Ryuichi Arafune

    • MANA, NIMS

  • Tai-Chang Chiang

    • University of Illinois at Urbana-Champaign