A CH3NH3PbI3 film for a room-temperature NO2 gas sensor with quick response and high selectivity

Abstract

A room-temperature NO₂ gas sensor with excellent performances is fabricated using an MAPbI₃ (MA = CH₃NH₃⁺) thin film. It presents a high response even under extremely low NO₂ concentrations. Its average response and recovery times are only ∼5 s and ∼25 s at room temperature, respectively, exhibiting its quick-responsive character. In addition, the MAPbI₃-based NO₂ sensor exhibits good selectivity. Interestingly, the sensitivity of the MAPbI₃-based NO₂ sensor is strikingly improved under high-pressure gas conditions. This phenomenon can be used for the online monitoring of chemical reaction processes and in situ detection of trace-level gas impurities under high-pressure conditions. Furthermore, based on theoretical calculations, a simple model is proposed to illustrate the corresponding gas-sensing mechanism.