High-Stability, Self-Powered Perovskite Photodetector Based on a CH3NH3PbI3/GaN Heterojunction with C60 as an Electron Transport Layer

We reported first photodetectors based on a CH3NH3PbI3/GaN heterojunction with or without an electron transport layer (ETL). Through the investigation, the device without an ETL showed good sensitivity, high stability, and repeatability. Particularly, when C60 was applied as the ETL, the device showed a self-powered characteristic with high stability. The best self-powered device with 6 nm C60 displayed an on/off ratio of greater than 5000, peak responsivity of 0.198 A/W, and detectivity of 7.96 × 1012 cm Hz1/2/W, which is comparable with the other reports. The high performance mentioned above was attributed mainly to the C60 layer, which can reduce the density of trap states and passivate the grain boundaries of the CH3NH3PbI3 absorbing layer to facilitate intermolecular charge transport.