High Selective SO2 Gas Sensor Based on Monolayer β-AsSb to Detect SF6 Decompositions

The density functional theory with nonequilibrium Green's function was adopted to explore the adsorption of SF6 decompositions (SO2, SOF2, SO2F2, H2S, and HF) on monolayer beta-AsSb as well as gas sensing response and selectivity using a simulated device. The adsorption on two side of monolayer beta-AsSb was compared. Among these five kinds of gas molecule, for both the As and Sb adsorption sites, SO2 exhibited the largest adsorption energy and electron transfer. The band gap of monolayer beta-AsSh experienced a significant decrease only when SO2 was adsorbed on the surface. All the five molecules can have chemical interactions with different degree according to density of states. The current-voltage property indicated that the monolayer beta-AsSb-based sensing device had response to all these five gases, especially at the voltage range from about 1.6 to 1.8 V. But the response to SO2 was obvious larger than other four gases for both As and Sb adsorption sites. The results suggest that monolayer beta-AsSb has high response and selectivity to SO2 which may stimulate future application for outstanding performance SO2 gas sensor in SF6-based gas insulated equipment.