Improved Low‐Temperature Solution‐Growth of CsPbBr3‐nCln Single Crystals for X‐Ray Detection

Abstract The dark current drift caused by severe ion migration in all‐inorganic perovskite CsPbBr 3 degrades the stability of X‐ray detection performance under a high electric field. The halogen doping is an effective method to improve the properties of the perovskites. In this work, the all‐inorganic Cl‐doped perovskites CsPbBr 3‐n Cl n (n=0, 0.1 and 0.5) single crystals were grown by a modified low‐temperature inverse temperature crystallization (ITC) method with the growth temperature lower than the phase transition point. The trap density decreased to 3.05×10 10 cm −3 and the carrier mobility increased to 124.75 cm 2 V −1 s −1 for the optimum component of CsPbBr 2.9 Cl 0.1 . Furthermore, by designing the detector with an asymmetric electrode configuration, CsPbBr 2.9 Cl 0.1 detector showed super low dark current and an outstanding hard X‐ray induced photo‐response under a high voltage of 200 V. Consequently, the CsPbBr 2.9 Cl 0.1 perovskite detector delivers a high sensitivity (5593.24 μC Gy air −1 cm −2 ) and a low detection limit (0.68 μGy air s −1 ). Our low temperature solution grown Cl‐doped all‐inorganic perovskite single crystals efficiently improve the photoelectric properties and enhance the X‐ray detection performance.