High‐Quality 0D Cs₄PbBr₆‐Based Dense Wafer for High‐Sensitivity X‐Ray Detection and High‐Resolution Imaging in Harsh Environment

Abstract The use of metal halides promotes the development of X‐ray detectors (XDs) owing to their excellent X‐ray absorbance, electrically benign defects, and large mobility−lifetime (µτ) product. Yet the severe baseline drift, size limitation, large dark current, and mediocre stability are still waiting to be solved. Herein, high density size‐scalable Cs₄PbBr₆ wafer‐based XD is constructed by the hot isostatic‐pressed method for the first time. Meanwhile, different Br⁻ vacancy (V_Br) concentration‐based Cs₄PbBr₆ is realized. The role of V_Br in electrical structure and charge transport is highlighted by density functional theory and experimental measurement. Moreover, the further study points the 0D structure endows Cs₄PbBr₆ with high activation energy for ionic transport (1044 meV) and bandgap (3.88 eV), which finally results in an ultra‐stable baseline and thermal stability. On the basis of efficient response (7068 µC Gy_air⁻¹ cm⁻²), reliable current output, ultra‐low detection limit (1.75 nGy_air s⁻¹), high spatial resolution (5.2 lp mm⁻¹ at modulation transfer function = 0.2), fast response speed and radiation stabilities (>1000 Gy_air), the high‐resolution X‐ray images under broad energy range (20–160 keV) are realized on both single‐pixel and linear scanning mode, thus holding huge potential for medical diagnosis, safety inspection, and outer space detection.