Stable and Ultrasensitive X‐Ray Detectors Based on Oriented Single‐Crystal Perovskite Rods

Abstract Metal‐halide perovskite single crystals (SCs) are promising candidates for next‐generation X‐ray detectors. X‐ray detectors fabricated using perovskite FAPbI 3 SCs exhibit high detection sensitivity. However, two pressing issues still need to be addressed for practical applications: the orientation‐controlled growth and environmentally friendly acquisition of high‐quality FAPbI 3 SCs. In this study, large high‐quality perovskite FAPbI 3 SC rods (SCRs) with unique orientation are grown using a biomass‐derived green solvent. Owing to the high carrier mobility and large bulk resistivity of the oriented FAPbI 3 SCRs, the SC detectors realize a record high X‐ray detection sensitivity (2.16 × 10 5 µC Gy −1 cm −2 ) and high sensitivity to dark current density ratio (1.93 × 10 9 Gy −1 s). Furthermore, the detectors exhibit both ultralow dark and X‐ray current drifts, as well as a detection limit of 2 nGy s −1 . These characteristics enable the detectors to achieve high‐resolution X‐ray imaging, even at dose rates as low as 12 nGy s −1 . This study not only contributes a new technical solution for low‐dose X‐ray detection, but also establishes a new approach for the low‐cost and environmentally friendly production of core materials for X‐ray detectors.