Layer-dependent bandgap and electrical engineering of molybdenum disulfide

Abstract Exploring the state of MoS2 with different layers is a matter of interest in band gap and electrical engineering. In this paper, metal-oxide-semiconductor field-effect transistors based on MoS2 are studied, with respect to the number of MoS2 layers in the channel. The residual stress changes from 0.4568 to 1.9234 GPa with number of MoS2 layers increasing from one to five. At the same time, the band gap of the MoS2 decreases by 45.4% from 1.727 to 0.943 eV. Our simulations show that when residual stress increases, the Schottky barrier height and the MoS2/H–SiO2 interface barrier height can significantly decrease and the drain-source and direct tunneling currents will inevitably increase. The results in this paper provide a theoretical basis for the fabrication of strained MoS2 devices.