Ultrasensitive and Robust 120 keV Hard X-Ray Imaging Detector based on Mixed-Halide Perovskite CsPbBr_(3?N)i_n Single Crystals

摘要

The relatively low resistivity and severe ion migration in CsPbBr3 significantly degrade the performance of X-ray detectors due to their high detection limit and current drift. The electrical properties and X-ray detection performances of CsPbBr3-nIn single crystals are investigated by doping the iodine atoms into the melt-grown CsPbBr3. The resistivity of CsPbBr3-nIn single crystals increases from 3.6 x 10(9) (CsPbBr3) to 2.2 x 10(11) (CsPbBr2I) omega cm, restraining the leak current and decreasing the detection limit of the detector. Additionally, CsPbBr3-nIn single crystals exhibit stable dark currents, arising from their high ion migration activation energy. A record sensitivity of 6.3 x 104 mu C Gy(-1) cm(-2) (CsPbBr2.9I0.1) and a low detection limit of 54 nGy s(-1) (CsPbBr2I) are achieved by CsPbBr3-nIn single crystals for the 120 keV hard X-ray detection under a 5000 V cm(-1) electrical field. The CsPbBr2.9I0.1 detector shows a stable current response with a dark current density of 0.58 mu A cm(-2) for 30 days and clear imaging for 120 keV Xrays at ambient conditions. The effective iodine atom doping strategy makes the CsPbBr3-nIn single crystals promising for reproducible high-energy hard X-ray imaging systems.