Flexible Perovskite X‐Ray Detectors through Interfacial Modification with Perylene Diimide

Abstract Flexible direct X‐ray detectors based on perovskites have great potential for X‐ray imaging due to their high sensitivity, low detection limit, low‐cost, and large‐area fabrication. However, these detectors perform inefficiently at X‐ray‐to‐current conversion because of inadequate functional layer thickness and charge‐carrier recombination. Here, the fabrication of an integrated, self‐powered X‐ray detector based on CsPbBr 3 quantum dots and a MAPbI 3 photoelectric conversion layer embedded with perylene diimide molecules is reported. In addition to optimizing crystal domain formation and charge carrier extraction, the perylene diimide molecules also improve the electron mobility of MAPbI 3 films by twofold. The integrated perovskite‐based X‐ray detector has a sensitivity of 143 169 ± 848 µC Gy air −1 cm −2 and a detection limit of 30.77 nGy s −1 . The perylene diimide molecule at the grain boundary of MAPbI 3 shows defect passivation and charge collection characteristics, leading to stable output over 30 bending cycles. This hybrid molecular approach provides insight into a general method to modify device performance using perylene diimide‐integrated detectors for X‐ray imaging of 3D objects with curved surfaces.