Self‐Powered X‐Ray Detector Based on All‐Inorganic Perovskite Thick Film with High Sensitivity Under Low Dose Rate

Hybrid perovskite materials have been one of the brightest spotlights in the radiation detection research fields due to their higher carrier mobility and lower trap state density in recent years. In this paper, the CsPbBr 3 microcrystal thick film is successfully prepared using a low‐cost facile solution synthesis method. The properties of samples are characterized by field‐emission scanning electron microscope (FE‐SEM), X‐ray diffraction (XRD), and UV‐vis diffuse reflectance spectrum (UV‐vis DRS). In addition, X‐ray detectors based on the CsPbBr 3 microcrystal thick film are fabricated and the photoelectric properties of the detectors are further improved through the multiple‐times dissolution–recrystallization method. An improved sensitivity of 470 µC Gy air −1 cm −2 is obtained for X‐ray photodetector based on recrystallized CsPbBr 3 microcrystal thick film at zero bias under a remarkably low dose rate (0.053 µGy air s −1 ). This sensitivity is over 20 times higher than that of α‐Se X‐ray detectors working at a much higher field of 10 V µm −1 . The current investigation can provide an efficient low‐cost and facile method to fabricate self‐powered X‐ray detectors based on CsPbBr 3 microcrystal thick film that work normally at low radiation dose rate.