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

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 MoS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> and WS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> mono- and bilayer channels. Our results highlight low contact resistances below 200 Ω μ m in monolayer systems, providing that a sufficiently high carrier concentration of 3 × 10¹³ ~cm⁻² is achieved, either through conventional or dynamical (electrostatic) doping. Contact resistances can be further lowered down to 50 Ω μ m by using bilayers and the adequate type of doping.