A Theoretical Study on Adjustment of Negative Differential Resistance Effect in Monolayer GeS via Substitutional Doping

Abstract

Density functional theory and nonequilibrium Green's function theory are used to systematically explore the electronic structures and transport characteristics of doped monolayer GeS with group V (N, P, As) atoms. The calculated band structures demonstrate that the doping of N, P, and As atoms results in the transformation of monolayer GeS from semiconducting to metallic properties. Further, an obvious negative differential resistance (NDR) behavior is obtained by altering the dopant atom and the doping concentration. In particular, for N‐doped monolayer GeS, the NDR behavior appears in the millivolt region as the doping concentration decreases, and the current peak‐to‐valley ratio (PVR) is up to 107 (order of magnitude 7). These findings have significant implications for future design of low‐power novel nanoelectronic devices based on monolayer GeS.