Ion Exchange-Enabled High-Speed Self-Power Photodetector Arrays Based on Large-Scale Monocrystalline Perovskite Films

Cesium lead halide perovskites exhibit valuable electrical and optical properties and have potential applications in photodetectors. In this study, large-area monocrystalline CsPbBr 3 films were grown via chemical vapor deposition and subsequently transformed into CsPb(Br 0.5 I 0.5 ) 3 thin films via ion exchange. The results demonstrate that the substrate temperature and precursor reaction completeness significantly affect the growth of monocrystalline CsPbBr 3 films. Furthermore, large-area self-powered CsPb(Br 0.5 I 0.5 ) 3 photodetectors with a high switch ratio (>10 3 ) and fast response speed (108 μs/105 μs) were developed. Additionally, a CsPb(Br 0.5 I 0.5 ) 3 image sensor array capable of high-resolution pattern identification was fabricated. This work represents a substantial step toward synthesizing large-area, high-quality monocrystalline CsPbBr 3 and ion exchange films for potential optoelectronics applications.