Self-Powered Photodetector Based on Ag/CH₃NH₃PbI₃/C Asymmetric Dual-Terminal Device

CH₃NH₃PbI₃ is capable of exhibiting a superior photoresponse to visible light, but its self-powered devices are typically formed through p-n junctions. In this study, we fabricated a Ag/CH₃NH₃PbI₃/C dual-terminal asymmetric electrode device using a single CH₃NH₃PbI₃ perovskite micro/nanowire, enabling both the photoresponse and self-powered characteristics of CH₃NH₃PbI₃ to visible light. Compared with traditional p-n junction devices, this simple device demonstrates enhanced interface photovoltaic effects by optimizing the combination of the Ag electrode with CH₃NH₃PbI₃, resulting in superior self-powered characteristics. Under low bias voltage, the device achieves a significant on/off ratio of 10³, with superior sensitivity and responsivity as well as a maximum rectification ratio of about 12. The photogenerated voltage and current reach approximately 0.8 V and 2 nA, respectively. This simple, compact, and self-powered asymmetric device exhibits great potential for applications in self-powered optoelectronics and wearable devices. This research provides a promising approach for recognizing and utilizing surface state effects in single nanoscale structures.