Qiu Xiaoqian, Wang Yiren, Jiang Yong
Key Laboratory for Nonferrous Metal Materials Science and Engineering (MOE), School of Materials Science and Engineering, Central South University Changsha 410083 China
State Key Laboratory for Powder Metallurgy, Central South University Changsha 410083 China.
RSC Adv. 2020 Aug 4;10(48):28725-28730. doi: 10.1039/d0ra04833j. eCollection 2020 Aug 3.
The performance of MoS based devices is closely related to the quality and defect morphology of the monolayer MoS deposited on metal. First-principles calculations were performed to investigate the vacancy effects of Au-mMoS 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-mMoS contact, while S-vacancy (hollow site at interface, V) has the lowest formation energy under Mo-rich environments. Electron and charge redistribution analysis of defective Au-mMoS contact indicate that the lower contact resistance and higher electron injection efficiency of defective Au-MoS contact than perfect ones. Notably, the S-vacancy at top layer showed better electronic performance than that at bottom layer of monolayer MoS in the contact. High quality n-type Au-mMoS contact can therefore be expected through defect engineering.
基于MoS的器件性能与沉积在金属上的单层MoS的质量和缺陷形态密切相关。进行了第一性原理计算以研究Au-mMoS接触的空位效应。在我们的计算中考虑了四种可能的S空位和一种Mo空位。能量研究表明，在Au-mMoS接触中，S空位比Mo空位更容易形成，而在富Mo环境下，S空位（界面处的空心位点，V）具有最低的形成能。对有缺陷的Au-mMoS接触的电子和电荷重新分布分析表明，有缺陷的Au-MoS接触比完美接触具有更低的接触电阻和更高的电子注入效率。值得注意的是，在接触中，单层MoS顶层的S空位比底层的S空位表现出更好的电子性能。因此，通过缺陷工程有望实现高质量的n型Au-mMoS接触。
