Sensing the polar molecules MH3 (M=N, P, or As) with Janus NbTeSe monolayer

The unique intrinsic electric field with prominent physical and chemical properties of Janus TMDs have attracted extensive attention in device applications. In this work, the performance of Janus NbTeSe monolayer as a gas sensor is systematically investigated towards (N, P, and As)H3 molecules combining first-principles calculations and non-equilibrium Green’s function formalism. The adsorption energies and configurations of the molecules on different sites of Janus NbTeSe are determined. It is found AsH3 exhibits a stronger interaction with the substrate than NH3 and PH3, implying Janus NbTeSe is more sensitive towards AsH3. Besides, the visible difference of adsorption energies for the molecules on two sides shows the selectivity of the NbTeSe monolayer. Notably, the interaction between the molecules and the substrate becomes weaker under strain-driven, indicating the fast recovery and re-utilization of NbTeSe as the gas sensor device. Importantly, Janus NbTeSe exhibits a high anisotropic transport behavior, the modification of I−V responses correspondingly performs a surface-dependent trend. With higher gas sensitivity, surface selectivity and desorption property by strain-driven, NbTeSe monolayer are proposed a compelling and feasible candidate for gas sensing devices.