First-principles study of vacancy defects at interfaces between monolayer MoS2 and Au

Xiaoqian Qiu; Yiren Wang; Yong Jiang

doi:10.1039/d0ra04833j

First-principles study of vacancy defects at interfaces between monolayer MoS₂ and Au

RSC Adv. 2020 Aug 4;10(48):28725-28730. doi: 10.1039/d0ra04833j. eCollection 2020 Aug 3.

Authors

Xiaoqian Qiu¹, Yiren Wang¹, Yong Jiang^{1

2}

Affiliations

¹ Key Laboratory for Nonferrous Metal Materials Science and Engineering (MOE), School of Materials Science and Engineering, Central South University Changsha 410083 China [email protected] [email protected].
² State Key Laboratory for Powder Metallurgy, Central South University Changsha 410083 China.

Abstract

The performance of MoS₂ based devices is closely related to the quality and defect morphology of the monolayer MoS₂ deposited on metal. First-principles calculations were performed to investigate the vacancy effects of Au-mMoS₂ contact. Four possible S-vacancy and a Mo-vacancy were considered in our calculations. Energetic studies show that S-vacancies are easier to form than Mo-vacancy in Au-mMoS₂ contact, while S-vacancy (hollow site at interface, V_S4) has the lowest formation energy under Mo-rich environments. Electron and charge redistribution analysis of defective Au-mMoS₂ contact indicate that the lower contact resistance and higher electron injection efficiency of defective Au-MoS₂ contact than perfect ones. Notably, the S-vacancy at top layer showed better electronic performance than that at bottom layer of monolayer MoS₂ in the contact. High quality n-type Au-mMoS₂ contact can therefore be expected through defect engineering.