Vacuum‐Assisted Growth of Single Crystal Perovskite Arrays toward Ultralow Dark Current Photodetectors

Abstract Metal halide perovskites are widely employed in photodetectors (PDs) due to their exceptional photoelectric conversion ability. However, the high dark current induced by defect states during perovskite crystallization has not been well resolved, which enormously deteriorates the sensitivity of PD. Herein, a vacuum‐assisted template‐confined growth method is proposed to successfully fabricate high‐quality single crystal perovskite microwire arrays with low defect states and superior photoelectric characteristics. Experimentally and theoretically, it is proved that the fabricated perovskite microwire arrays PDs exhibit superior performance with commendable responsivity of 0.49 A W −1 and detectivity surpassing 1.21 × 10 13 Jones, which profits from ultralow dark current of ≈200 fA at a 5 V bias. Particularly, the perovskite microwire arrays PD behaves the characteristics of flexible robust stability and high‐definition image recognition. This work provides a universal strategy for optimizing perovskite crystal quality and constructing high‐performance optoelectronic devices in many scenarios.