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

Abstract

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 mMoS2/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 mMoS2 contacted with metals. As a result, the tunneling barrier is reduced. The Schottky barrier height (SBH) is increased in mMoS2 contacted with Mg, Al, In, and Au, but is reduced in defective mMoS2 contacted with Cu, Ag, and Pd. Furthermore, the pinning factor S are 0.227, 0.238, and 0.238 for the VS, VMo, and SMo in mMoS2, but the S value is only 0.030 for substitution of S by Mo (MoS) in mMoS2. 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.