High Selective SO2 Gas Sensor Based on Monolayer $\beta$ -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 $ -AsSb 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.