Search

Organic-inorganic perovskite single crystals (SCs) are considered promising semiconductors for high-sensitivity X-ray detectors because of their strong X-ray interaction, low-temperature processability, and excellent properties such as long diffusion length, low defect density, and long carrier lifetime. However, the specific pulse response of MAPbBr 3 SC-based X-ray detectors frequently exhibits a tail and over/undershoots at several conditions, which degrades the X-ray image quality; however, no detailed analysis of these characteristics has been reported thus far. For high-resolution X-ray imaging, it is necessary to obtain an ideal pulse response that is free of tails and over/undershoots. In this study, we investigated the specific X-ray responses of solution-grown MAPbBr 3 SC-based X-ray detectors under various externally applied voltages. Based on the study on charge carrier dynamics, we analyzed the origin of the tail and over/undershoots in X-ray pulse response shapes. We theoretically verified that the unideal pulse response in perovskite SC-based X-ray detectors is attributed to the defect states inherent in perovskite SCs. • X-ray responses of MAPbBr 3 single-crystal detectors with different electrodes are investigated. • The specific pulse responses of the detectors show tail and over/undershoots. • Tail and overshoots can be interpreted as de-trapping and trapping, respectively, on shallow traps. • Undershoot is caused by diffusion currents due to the internal fields and unoccupied vacancies. [ABSTRACT FROM AUTHOR]

Perovskite X-ray detectors are actively investigated because of their exceptional properties, including their significant attenuation coefficient, low defect density, excellent transport characteristics, easy growth, and high sensitivity to X-ray photons. However, perovskite-based high-energy X-ray detectors on the MeV scale are rarely explored. In this study, we investigate the optoelectronic characteristics and radiation detection capabilities of triple-cation Cs 0.05 FA 0.9 MA 0.05 PbI 3 single crystals (CSC) grown using the inverse temperature crystallization method. The CSCs with a reduced Goldschmidt tolerance factor owing to the presence of Cs and MA ions exhibit exceptional properties, including a bandgap of 1.447 eV, low dark current, and self-powered response to X-ray irradiation. The X-ray absorption rate of 36 keV exceeded 99% with a CSC thickness of 2 mm, demonstrating its strong stopping power. Moreover, the CSC detectors exhibit precise linear responses to varying X-ray doses and dose rates with R2 values close to 1 and relative standard deviation (RSD) values below 3% under all the tested conditions. In addition, the detector effectively detected high-energy X-rays of up to 15 MV with minimal variations in the RSD values. These findings highlight the potential of CSC as promising materials for high-performance X-ray detectors. • Triple-cation lead–halide perovskites for high-energy X-ray detection were studied. • CSC detector has uniform linear response to varying X-ray doses and rates. • CSC detector can detect high-energy X-rays of up to 15 MeV. • CSC demonstrated remarkable promise as excellent self-powered X-ray detectors. [ABSTRACT FROM AUTHOR]