Flexible Self-Powered Vertical Photodetectors Based on the [001]- Oriented CsPbBr3 Film

Flexible devices have aroused great interest due to their potential for wearable and portable applications. In this paper, the [001]-oriented all-inorganic perovskite CsPbBr3 films were grown on a flexible polyimide substrate, and the corresponding flexible self-powered photodetectors (PDs) were prepared. The [001]-oriented CsPbBr3 films have an atomically flat surface and a low defect density. Under zero bias voltage and 405 nm irradiation, the flexible PD presents a responsivity of 151.9 mA W-1 and a specific detectivity of 1.895 x 1013 Jones under a light intensity of 2 mu W cm-2 and a photocurrent on/off ratio of 4.54 x 106 under a light intensity of 165 mW cm-2. The CsPbBr3 PDs can work without an external power supply and are typical self-powered detectors. In addition, the detector still exhibits excellent flexibility and electrical stability after the repeated bending with the 4 mm radius. This study is expected to promote the commercial application of large-area flexible perovskite-based photoelectronic devices.