Trap regulation of zero-dimensional Rb4CdCl6 perovskite for high-temperature X-ray imaging

Low-dimensional lead-free metal halide perovskites have garnered significant attention due to their potential applications in nondestructive testing. However, achieving scintillators that facilitate efficient X-ray imaging remains a major challenge, primarily due to the inherent difficulty of low concentration in deep traps. Here, a novel design strategy is introduced that modulates A-site element occupancy, thereby fine-tuning the electronic structures and photophysical properties of perovskites. We present a novel zero-dimensional halide perovskite Rb 4 CdCl 6 :Mn 2+ , A + (where A + represents Li + , Na + , K + , Ag + ). The trap-regulated generation of additional Cl vacancies significantly enhances the afterglow performance, thereby enabling its applications in high-temperature X-ray imaging, and thermally stimulated imaging. Notably, Na + -doped Rb 4 CdCl 6 :Mn 2+ exhibits optimal trap distribution and superior thermally quenched-resistant radioluminescence, with a light yield 1.4 times higher at 493 K compared to room temperature. Moreover, the prepared film exhibits a detection limit as low as 63.5 nGy s −1 in high-temperature environments, along with a spatial resolution exceeding 20 lp mm −1 . Upon cessation of irradiation, intense X-ray persistent luminescence emission (X-PersL) is triggered under thermal stimulation, realizing delayed imaging, which can be attributed to charge carrier compensation and redistribution mechanisms. This work proposes an innovative design strategy for high-efficiency perovskite scintillators, expanding their applications in advanced X-ray detection.