RF Sputtered Nb-Doped MoS(2) Thin Film for Effective Detection of NO(2) Gas Molecules: Theoretical and Experimental Studies

[Image: see text] Doping plays a significant role in affecting the physical and chemical properties of two-dimensional (2D) dichalcogenide materials. Controllable doping is one of the major factors in the modification of the electronic and mechanical properties of 2D materials. MoS(2) 2D materials have gained significant attention in gas sensing owing to their high surface-to-volume ratio. However, low response and recovery time hinder their application in practical gas sensors. Herein, we report the enhanced gas response and recovery of Nb-doped MoS(2) gas sensor synthesized through physical vapor deposition (PVD) toward NO(2) at different temperatures. The electronic states of MoS(2) and Nb-doped MOS(2) monolayers grown by PVD were analyzed based on their work functions. Doping with Nb increases the work function of MoS(2) and its electronic properties. The Nb-doped MoS(2) showed an ultrafast response and recovery time of t(rec) = 30/85 s toward 5 ppm of NO(2) at their optimal operating temperature (100 °C). The experimental results complement the electron difference density functional theory calculation, showing both physisorption and chemisorption of NO(2) gas molecules on niobium substitution doping in MoS(2).