The impact of S vacancies on the modulation of the work function and Schottky barrier at the Au/MoS2 interface

Abstract

The S vacancy at metal/ MoS 2 interface plays a much important role than the semiconductor itself. In this work, the influence of different configurations of S vacancy concentrations on the effective work function and band structure of the Au/ MoS 2 interface has been investigated systematically using first-principles calculations. The study specifically explores the effective work function of the Au/ MoS 2 interface, the deviation of interface effects from the vacuum work function, and the dipole moment caused by interface charge transfer. The results reveal that the electronic work function of Au/ MoS 2 increases with the increase in S vacancy concentration, but the rate of increase tends to slow down with higher S concentrations. The variation in the effective work function of the Au/ MoS 2 interface may be attributed to the presence of S vacancies and the exposure of Mo atoms. S vacancies lead to a reduction in the Schottky barrier, resulting in increased leakage current. The Fermi pinning caused by S vacancy concentration and location is also observed. The results obtained in this study can serve as a theoretical foundation for applications in electronic devices that rely on metal/ MoS 2 contact.