Ultrahigh Selectivity H₂S Gas Sensor Based CsPbBr₃ Perovskites via Pb–S Bonding Interaction

Abstract

High selectivity and sensitivity sensing of H₂S gas play a decisive role in the early detection of sulfide solid-state battery failure. Herein, we construct the CsPbBr₃ perovskite-based sensor that exhibits outstanding gas-sensing performance to H₂S 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 CsPbBr₃ for H₂S 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 H₂S 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.