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

Metal-halide perovskite single crystals (SCs) are promising candidates for next-generation X-ray detectors. X-ray detectors fabricated using perovskite FAPbI₃ 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 FAPbI₃ SCs. In this study, large high-quality perovskite FAPbI₃ 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 FAPbI₃ SCRs, the SC detectors realize a record high X-ray detection sensitivity (2.16 × 10⁵ µC Gy^-1 cm^-2) and high sensitivity to dark current density ratio (1.93 × 10⁹ 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.