A highly sensitive and selective SnS2 monolayer sensor in detecting SF6 decomposition gas

A novel 2D material SnS2 with an appropriate bandgap and high mobility, has been fabricated successfully and shows promising potential in electronic circuits. However, its applications in gas sensing are still poorly studied. In this work, the sensing behavior of SnS2 monolayer for SF6 and its five decomposition gases (SO2F2, SOF2, H2S, HF, and SO2) is investigated by combining density functional theory and nonequilibrium Green's function. The calculated adsorption properties indicate that the SnS2 monolayer and the six gases are interacted by physisorption mechanism. Only the adsorption of H2S induces the work function of SnS2 monolayer to decrease by 0.59 eV. Moreover, due to the electronic property change near the Fermi level modified by H2S, the current-voltage curves are performed to confirm that the conductivity of SnS2 monolayer increases obviously after H2S adsorption. SnS2 monolayer shows a high sensitivity for H2S detection, reaching to 63.5%. Overall, SnS2 monolayer deserves to be further explored as a promising FET-based sensing candidate with high sensitivity to detect typical partial discharge gas (H2S) in SF6-based gas-insulated switchgear.