Ultrahigh Selectivity H 2 S Gas Sensor Based CsPbBr 3 Perovskites via Pb–S Bonding Interaction

High selectivity and sensitivity sensing of H 2 S gas play a decisive role in the early detection of sulfide solid-state battery failure. Herein, we construct the CsPbBr 3 perovskite-based sensor that exhibits outstanding gas-sensing performance to H 2 S at room temperature, including high selectivity, fast response/recovery speed (73.5/275.6 s), humidity insensitivity, and long-term stability (6 weeks without degradation). The excellent selectivity of CsPbBr 3 for H 2 S results from the formation of lead–sulfur (Pb–S) bonds exclusive to other molecules and upshifted the Fermi level at the perovskite interface by density functional theory (DFT) calculations. The in-situ experiments reveal the interaction of Pb–S bonding and the transformation of H 2 S molecules on the perovskite surface. The simple synthesis method and unique sensing mechanism based on perovskite semiconductors help build the room-temperature metal halide perovskite (MHP)-based gas sensors with high selectivity and fast response/recovery speed for solid-state battery failure detection in the future.