Resolving Interface Barrier Deviation from the Schottky-Mott Rule: A Mitigation Strategy via Engineering MoS2-Metal van der Waals Contact

Zhongjun Li; Yahui Zheng; Guojun Li; Hanxi Wang; Weiduo Zhu; Haidi Wang; Zhao Chen; Yupeng Yuan; Xiao Cheng Zeng; Yucheng Wu

doi:10.1021/acs.jpclett.3c00056

Resolving Interface Barrier Deviation from the Schottky-Mott Rule: A Mitigation Strategy via Engineering MoS₂-Metal van der Waals Contact

J Phys Chem Lett. 2023 Mar 30;14(12):2940-2949. doi: 10.1021/acs.jpclett.3c00056. Epub 2023 Mar 17.

Authors

Zhongjun Li^{1

2}, Yahui Zheng¹, Guojun Li¹, Hanxi Wang¹, Weiduo Zhu¹, Haidi Wang¹, Zhao Chen¹, Yupeng Yuan³, Xiao Cheng Zeng^{4

5}, Yucheng Wu¹

Affiliations

¹ School of Physics, Hefei University of Technology, Hefei 230009, Anhui, China.
² State Key Laboratory of Quantum Optics and Quantum Optics Devices, Shanxi University, Taiyuan 030006, China.
³ School of Materials Science and Engineering, Anhui University, Hefei 2300601, Anhui, China.
⁴ Department of Materials Science & Engineering, City University of Hong Kong, Kowloon 999077, Hong Kong, China.
⁵ Department of Chemistry, University of Nebraska─Lincoln, Lincoln, Nebraska 68588, United States.

PMID: 36930804
DOI: 10.1021/acs.jpclett.3c00056

Abstract

The Schottky barrier (SB) in the ultraclean van der Waals contact between two-dimensional (2D) MoS₂ and three-dimensional (3D) indium (In) strikingly deviates from the Schottky-Mott limit (SML). Herein, on the basis of first-principles calculation, the origin of the SB deviation is brought to bear, as well as a strategy for mitigating the SB deviation. In light of the good agreement between the SB and the corrected SB by interface potential difference (ΔV) and Fermi -level shift (ΔE_F) based on the SML, the SB deviation is attributed to the combined effects of ΔV and ΔE_F. Furthermore, when a Au, Sc, or Ti thin film is coated on the back side of In, the SB deviation and the sum of ΔV and ΔE_F decrease similarly. Importantly, in the Ti coating situation, the SB is reduced to 0.12 eV, notably smaller than the value of 0.30 eV in the Au coating case. This interface engineering can be generalized to regulate the SB between a 2D semiconductor and a 3D alloy.