Cs₃Cu₂I₅ Perovskite Nanoparticles in Polymer Matrix as Large-Area Scintillation Screen for High-Definition X-ray Imaging

Perovskite scintillators have been widely used in X-ray detection; however, lead-based perovskite scintillators with strong self-absorption reduce the optical-coupling efficiency, significantly resulting in a relatively low optical yield. Herein, we prepared self-trapped exciton-emitting lead-free perovskite nanoparticles (Cs3Cu2I5) using a green antisolvent method and fabricated large-scale (Ø = 10 cm) scintillation screens by uniformly dispersing them in a transparent styrene monomer. The antisolvent optimized the crystallization of Cs3Cu2I5, achieving a photoluminescence quantum yield of 87.2%. The scintillation screen prepared in the liquid phase significantly improves the luminous uniformity and led to a high spatial resolution of 7.3 lp/mm. It exhibits an excellent linear response to X-ray dose rate and a low detection limit of 63 nGyair/s. Besides, the transparent matrix enhances the stability of Cs3Cu2I5 with remarkable radiation-resistant hardness even under continuous X-ray irradiation for 120 min.