Two dimensional (2D) molybdenum disulfide (MoS 2 ) has an unique intrinsic influence on gas sensing applications. The effect of S and Mo vacancy creation increases the sensing nature of BBr 3 and SF 4 toxic gases. In this work, we have theoretically investigated the sensing capabilities and the electron transport behavior of armchair S vacancy (AmS-MoS 2 ), armchair Mo vacancy (AmMo-MoS 2 ), zigzag S vacancy (ZigS-MoS 2 ), and zigzag Mo vacancy MoS 2 monolayer with the highly toxic gases include of BBr 3 and SF 4 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 BBr 3 andSF 4 gas molecules after adsorption. Among the devices, SF 4 adsorption on AmMo-MoS 2 and BBr 3 adsorption on ZigMo-MoS 2 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-MoS 2 for SF 4 adsorption and ZigMo-MoS 2 for BBr 3 adsorption. All the results indicate that AmMo-MoS 2 and ZigMo-MoS 2 device shows beneficial results compared with the other devices. Hence, AmMo-MoS 2 and ZigMo-MoS 2 can be used for SF 4 and BBr 3 gas sensing applications.

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A comprehensive investigation with the help of 3D device simulation, we demonstrate the impact of fringing field on shell radius of InAs-GaSb core–shell nanowire n-channel tunnel field effect transistor (TFET) in this paper. Increase in shell radius intensifies the magnitude of fringing electric field towards shell region. This results in generation of depletion zone in the shell near the gate edge affects the device performance metrics such as on current and threshold voltage. It is demonstrated that by appropriate gate engineering the influence of fringing electric field can be circumvent. High-k spacer dielectric at the gate underlap shows improvement in device performance metrics such as on current with sub 2.3 k B T q subthreshold swing. An investigation of the effect of drain voltage on the device characteristics exhibits the privation of tunneling resistance limited region. Furthermore, the output characteristics for such an architecture bear a resemblance to long channel MOSFET (metal oxide semiconductor field effect transistor).