Volatile organic compound gas sensors based on methylammonium lead iodide perovskite operating at room temperature

Methylammonium lead iodide (MAPbI 3 ) perovskite thin film has been successfully applied to a volatile organic compound (VOC) gas sensor that can operate at room temperature. In this study, ∼100 nm-thick MAPbI 3 film shows good reversibility and repeatability as a VOC gas sensor. The resistance of the MAPbI 3 film substantially decreases when it is exposed to VOC vapour and recovers back to high resistance when the VOC gas is removed. Adsorption of VOC gas molecules to vacancies in MAPbI 3 film might lead to charge trap passivation. The VOC sensor based on perovskite thin film is tested in terms of film thickness, applied bias voltage, and polarity of VOC. We expect that our VOC gas sensor based on solution-processed MAPbI 3 operating at room temperature has potential to be developed as a low cost and low power smart gas sensor. At room temperature, conductivity of methylammonium lead iodide perovskite was increased in the presence of volatile organic compound (VOC) gas, which was interpreted in the context of charge trap passivation mechanism.