Humidity Sensitivity Behavior of CH₃NH₃PbI₃ Perovskite

The CH₃NH₃PbI₃ (MAPbI₃) powders were ground by PbI₂ and CH₃NH₃I prepared by ice bath method. The humidity sensitive properties of an impedance-type sensor based on MAPbI₃ materials were systematically studied. Our results indicate that the MAPbI₃-based sensor has superior sensing behaviors, including high sensitivity of 5808, low hysteresis, approximately 6.76%, as well as good stability. Water-molecule-induced enhancement of the conductive carrier concentration was argued to be responsible for the excellent humidity sensitive properties. Interestingly, the humidity properties can be affected by red light sources. The photogenerated carriers broke the original balance and decreased the impedance of the sensor. This work promotes the development of perovskite materials in the field of humidity sensing.