First Principle Study of Mo and S Vacancy Effect in Armchair and Zigzag MoS2 2D Material For Gas Sensing Application

Abstract

Two dimensional (2D) molybdenum disulfide (MoS2) has an unique intrinsic influence on gas sensing applications. The effect of S and Mo vacancy creation increases the sensing nature of BBr3 and SF4 toxic gases. In this work, we have theoretically investigated the sensing capabilities and the electron transport behavior of armchair S vacancy (AmS-MoS2), armchair Mo vacancy (AmMo-MoS2), zigzag S vacancy (ZigS-MoS2), and zigzag Mo vacancy MoS2 monolayer with the highly toxic gases include of BBr3 and SF4 using first-principles calculations and Non-Equilibrium Green’s Function (NEGF) theory. The optimal configuration indicates that there is a considerable change in the bond length and bond angle of BBr3 andSF4 gas molecules after adsorption. Among the devices, SF4 adsorption on AmMo-MoS2 and BBr3 adsorption on ZigMo-MoS2 shows enhanced adsorption energy of 0.9233 eV and 0.9987 eV, charge transfer of 0.111e and 0.233e respectively. The density of states, transmission spectrum, and I–V characteristic also show comparatively more changes after the adsorption of the gas molecule which reflects in the conductance and transport characteristic of AmMo-MoS2 for SF4 adsorption and ZigMo-MoS2 for BBr3 adsorption. All the results indicate that AmMo-MoS2 and ZigMo-MoS2 device shows beneficial results compared with the other devices. Hence, AmMo-MoS2 and ZigMo-MoS2 can be used for SF4 and BBr3 gas sensing applications.