Adsorption behavior of Janus MoSiGeN4 monolayer for gas-sensing application with high sensitivity and reuse

Abstract

Two-dimensional (2D) Janus materials have raised considerable attention from the scientific community because of their asymmetric structure and distinctive physical characteristics. Here, we theoretically study the surface gas adsorption effects on the monolayer MoSiGeN4 (MSGN) due to its high carrier mobility and tunable electronic properties. The results show that the built-in electric field in MSGN results in lower adsorption energies on the Si-side than that on the Ge-side. Additionally, the Si-side of MSGN exhibits higher sensitivity to NO2 detection, and the recovery time and conductivity of NO2 adsorption on MSGN are found to be 1.92 × 10−9 s and 138 k/(S × m−1), respectively. Particularly, the Si-side MSGN-based sensors have higher sensitivity for gas detection. This finding provides possibilities for gas sensors with selectivity and sensitivity based 2D Janus monolayers.