Sr-Doping All-Inorganic CsPbBr3 Perovskite Thick Film for Self-Powered X-ray Detectors

Abstract

The all-inorganic perovskite cesium lead bromine (CsPbBr3) has attracted much attention in the field of X-ray detectors because of its high x-ray absorption coefficient, high carrier collection efficiency, and easy solution preparation. The low-cost anti-solvent method is the main method to prepare CsPbBr3; during this process, solvent volatilization will bring a large number of holes to the film, leading to the increase of defects. Based on the heteroatomic doping strategy, we propose that Pb2+ should be partially replaced by Sr2+ to prepare leadless all-inorganic perovskite. The introduction of Sr2+ promoted the ordered growth of CsPbBr3 in the vertical direction, increased the density and uniformity of the thick film, and achieved the goal of CsPbBr3 thick film repairing. In addition, the prepared CsPbBr3 and CsPbBr3:Sr X-ray detectors were self-powered without external bias, maintaining a stable response during on and off states at different X-ray dose rates. Furthermore, the detector base on 160 µm CsPbBr3:Sr had a sensitivity of 517.02 µC Gyair−1 cm−3 at zero bias under the dose rate of 0.955 µGy ms−1 and it obtained a fast response speed of 0.053–0.148 s. Our work provides a new opportunity to produce cost-effective and highly efficient self-powered perovskite X-ray detectors in a sustainable way.

Perovskite materials in X-ray detection and imaging: recent progress, challenges, and future prospects

“…Very recently, in 2023, C. Liu and research group fabricated a compact and homogeneous perovskite film by incorporating Sr 2+ in CsPbBr 3 through the anti-solvent method. 181 They scrutinized the impact of introducing Sr 2+ in the perovskite material. They claimed that due to the incorporation of Sr 2+ , the density and uniformity of the film significantly increased.…”

“… 180 However, the X-ray detector derived from the film of CsPbBr3:Sr, grown by adopting the anti-solvent method, displayed the minimal LDDR of 0.955 nGy s −1 . 181 On the contrary, regarding wafer-based X-ray detectors, the device with the CsPbBr 3 –CsPb 2 Br 5 –CsPbI x Br 3- x composite wafer, developed through water-assisted co-precipitation and spray coating, unveiled the best sensitivity of 20 555.1 μC Gy −1 cm −2 among the wafer-based X-ray detectors. 184 However, the device from the wafer of Cs 2 AgBiBr 6 –BiOBr, synthesized by employing isostatic pressing, recorded a minimal LDDR of 95.3 nGy s −1 .…”