Performance analysis of a substrate-engineered monolayer MoS2 field-effect transistor

Abstract

We investigate the impact of different substrates on the performance of a monolayer MoS2 field-effect transistor (FET) by calculating the interface charge density between the MoS2 layer and the substrate using first-principle calculations based on density functional theory to provide details about the overlap of electron orbitals at the interface. The electrical characteristics of the monolayer MoS2 FET are determined by using the extracted interface charge density in numerical simulations. The electron transport behavior of the monolayer MoS2 FET is modeled using the nonequilibrium Green’s function with mode space (NEGF_MS) approach. We study and compare the performance of monolayer MoS2 FETs on different substrates, viz. SiO2, HfSiO4, Si3N4, HfO2, and h-BN. The results reveal that the monolayer MoS2 FET on the h-BN/Si substrate exhibits an on-current of 548 µA/µm and a subthreshold swing of 65 mV/dec.