Interfacial defect engineering on electronic states and electrical properties of MoS2/metal contacts

Understanding the interfacial properties between two-dimensional (2D) semiconductors and metal electrodes is vital for designing and realization of electronic devices. In this paper, first-principle calculations are done to study the influences of the defects on the interfacial electronic states of mMoS(2)/metal (metal=Mg, Al, In, Cu, Ag, Au, and Pd). It is found that the electron states at the interface are substantially increased if defects are induced in mMoS(2) contacted with metals. As a result, the tunneling barrier is reduced. The Schottky barrier height (SBH) is increased in mMoS(2) contacted with Mg, Al, In, and Au, but is reduced in defective mMoS(2) contacted with Cu, Ag, and Pd. Furthermore, the pinning factor S are 0.227, 0.238, and 0.238 for the V-S, V-Mo, and S-Mo in mMoS(2), but the S value is only 0.030 for substitution of S by Mo (Mo-S) in mMoS(2). Our findings are in good agreement with the experimental results. The results give insight into the contact physics of 2D semiconductors with metals and it is suggested that defects play a key role on the future generation electronic applications. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

In this study, first-principle calculations were used to investigate the influence of defects on the interfacial electronic states of mMoS(2)/metal systems. The results show that defects can significantly increase the electron states at the interface and reduce the tunneling barrier. Different metals have different effects on the electronic properties of mMoS(2) when defects are induced.