DFT-NEGF transport in 2D channels with semimetal contacts: the influence of doping and bilayers

Abstract

Using Density-Functional Theory and the Non-Equilibrium Green's Function formalism, we investigate the fundamental transport mechanisms through Sb and Bi semimetal contacts with MoS2 and WS2 mono- and bilayer channels. Our results highlight low contact resistances below 200 Omega mu m in monolayer systems, providing that a sufficiently high carrier concentration of 3 x 10(13) cm(-2) is achieved, either through conventional or dynamical (electrostatic) doping. Contact resistances can be further lowered down to 50 Omega mu m by using bilayers and the adequate type of doping.