First-Principle Insight into Ga-Doped MoS for Sensing SO, SOF and SOF.

First-principle calculations were carried out to simulate the three decomposition gases (SO, SOF, and SOF) of sulfur hexafluoride (SF) on Ga-doped MoS (Ga-MoS) monolayer. Based on density functional theory (DFT), pure MoS and multiple gas molecules (SF, SO, SOF, and SOF) were built and optimized to the most stable structure. Four types of Ga-doped positions were considered and it was found that Ga dopant preferred to be adsorbed by the top of Mo atom (T). For the best adsorption effect, two ways of SO, SOF, and SOF to approach the doping model were compared and the most favorable mode was selected. The adsorption parameters of Ga-MoS and intrinsic MoS were calculated to analyze adsorption properties of Ga-MoS towards three gases. These analyses suggested that Ga-MoS could be a good gas-sensing material for SO and SOF, while it was not suitable for SOF sensing due to its weak adsorption. This work provides a theoretical basis for the development of Ga-MoS materials with the hope that it can be used as a good gas-sensing material for electrical equipment.