Enhanced UV‐C Detection of Perovskite Photodetector Arrays via Inorganic CsPbBr₃ Quantum Dot Down‐Conversion Layer

Abstract Organometal halide perovskites have been considered as promising candidates for high‐performance low‐cost photodetectors. Nonetheless, as perovskite photodetectors are usually built on glass or polymer substrates, their UV‐C (200–280 nm) photodetection ability is quite limited due to the high absorption of glass or polymer substrates. Here, a uniform UV photodetector array which integrates perovskite photodiodes with inorganic CsPbBr₃ quantum dot (QD) fluorophor is reported. CsPbBr₃ quantum dot fluorophor not only acts as an efficient down‐conversion layer to convert UV light into 510 nm light, but also functions as a protective layer to prevent degradation of hybrid organic–inorganic perovskite by UV light. Compared to direct UV‐C (279 nm) detection with perovskite photodiode, the QD integrated photodetector shows a higher responsibility and detectivity to UV‐C, with values enhanced by 1 order in magnitude. This work provides a low‐cost and effective approach for all perovskite‐based UV‐C photodetectors and imagers.