Dynamic monolithic X-ray imager with enhanced performance via strain relaxation in metal-halide scintillators

Scintillation X-ray detectors find widespread applications in medical imaging, non-destructive testing, and security inspection. In recent years, metal halide materials have garnered attention as scintillators due to their superior properties, such as excellent luminescent performance, non-toxicity, and cost-effectiveness. Herein, we demonstrated that lattice strain in Cs5Cu3Cl6I2 significantly deteriorated its scintillation performance. However, the relaxation of lattice strain in Cs5Cu3Cl6I2 largely reduced nonradiative recombination and enhanced its stability. As a result, a high photoluminescence quantum yield (PLQY) of 99.5% was achieved in the strain-relaxed Cs5Cu3Cl6I2 scintillator. Furthermore, we developed the first monolithic X-ray imaging systems by integrating Cs5Cu3Cl6I2 scintillators with complementary metal-oxide-semiconductor (CMOS) technology, delivering superior imaging clarity with a high-resolution of 10 lp mm-1 (39 lp mm-1 under X-ray path amplification) and the capability of fast dynamic X-ray imaging. Moreover, the Cs5Cu3Cl6I2 monolithic X-ray imaging system showed remarkable stability against heat, humidity, and continuous X-ray irradiation. This research presents a feasible pathway for fabricating monolithic X-ray imagers and highlights their potential for practical applications. We anticipate that our findings will offer new insights into the strain engineering of metal halide scintillators and the structural design of advanced X-ray imaging systems.