A stable self-powered ultraviolet photodetector using CH3NH3PbCl3 with weak-light detection capacity under working conditions

Abstract

Organic–inorganic hybrid lead halide perovskite photodetectors have attracted worldwide attention in the field of optoelectronics. This study reports on a solution processable UV photodetector with a vertical-structure which contains a homogenous and dense layer of wide-bandgap methylammonium lead chlorine (CH₃NH₃PbCl₃) semiconductor as a photon-response absorber. The resultant CH₃NH₃PbCl₃-based UV photodetector achieves a fast response time of 7.76 μs and a high on/off ratio of over 5 × 10³. In addition, the photodetector exhibits an impressive light detecting ability with a specific detectivity (D*) of 7.08 × 10¹¹ Jones at an illumination intensity of 0.6 μW cm⁻² at 375 nm. Moreover, CH₃NH₃PbCl₃-based UV photodetectors without encapsulation show long-term stability (1200 h with 5% attenuation) under simulated operational conditions (25 °C, and 80% relative humidity in air). In addition, the CH₃NH₃PbCl₃-based photodetectors are proven to adapt to flexible substrates such as polyethylene naphthalate. This work reveals great potential of photodetectors with wide bandgap perovskites in the applications of UV light detection.