Detecting Decompositions of Sulfur Hexafluoride Using MoS2 Monolayer as Gas Sensor

The adsorption and gas sensing properties of monolayer MoS2 to five kinds of sulfur hexafluoride decompositions (SO2, SOF2, SO2F2, H2S, HF) were explored using the density functional theory combined with the nonequilibrium Green's function. The adsorption energy, electron transfer, charge density difference configurations, current-voltage (I-V) character using a two-electrode based device and transmission coefficient have been discussed. The results show that the adsorption of SO2 brings the largest adsorption energy as well as electron transfer. According to the simulated device, the unique negative conductance phenomenon was found for SO2. The MoS2 monolayer-based sensor has the highest response to SO2 when the bias voltage is 1.2 V, reaching 7.74 and has the largest response to H2S when 1.8 V. The transmission spectrum analysis shows that after introducing different gas molecules, the transmission coefficient has different changes in different energy ranges. This paper can provide a theoretical basis for designing MoS2 monolayer-based gas sensing device to detect the decompositions of sulfur hexafluoride or other specific gases.