A self-powered, flexible photodetector based on perovskite nanowires with Ni-Al electrodes

A flexible, self-powered, high-performance photodetector with the Ni/perovskite nanowires/Al structure has been fabricated successfully. CH3NH3PbI3 nanowires were synthesized by a simple spin-coating method at the appropriate temperature on a flexible substrate of polyimide (PI) film. The channel length between Ni-Al electrodes is about 15 μm. A built-in electric field has been established in the asymmetric device, which can effectively separate electron-hole pairs. The as-fabricated photodetector exhibited a high sensitivity from 405 nm to 808 nm. The external quantum efficiency (EQE) of the device is 33.7% at 405 nm with 0 V bias. Note that the device showed good performances of high sensitivity for detecting low incident power density. In addition, a responsivity of 0.227 A cm−2 was achieved under the incident light power of 1 × 10−8 W cm−2. The photodetector showed a high on/off ratio of 147, fast response speed of tens of microseconds, and excellent flexibility with a slight variation of photocurrent after bending test. These results create new opportunities for constructing low-cost, simple-process and high-performance photodetectors.