Multiple-engineering controlled growth of tunable-bandgap perovskite nanowires for high performance photodetectors

Controllable growth of perovskite nanowires is very important for various applications in optical and electrical devices. Although significant progress has been achieved in the solution method, a deep understanding of the mechanics of growing perovskite nanowires is still lacking. Herein, we developed an electrochemical method for growing the perovskite nanowires and studied the growth processes systematically. The initial nucleation and crystal growth could be controlled by simply varying the additive solvents, thus leading to two stable size ratio distributions of the perovskite nanowires. Further, with compositional engineering, the bandgap of the perovskites could be tuned from 1.59 eV to 3.04 eV. All the as-grown perovskite nanowires displayed a unique structure with high crystallization quality, contributing to a very high responsivity of 2.1 A W^-1 and a large on/off ratio of 5 × 10³ for the photodetectors based on the CH₃NH₃PbBr₃ nanowires. All of these findings demonstrate that the optimized solution method offers a new approach to synthesize perovskite nanowires for applications in photoelectric devices.