Fabrication of Highly Stable Cs3Cu2I5‐in‐Glass Composite for X‐Ray Imaging by SPS Technique

Abstract The development of all‐inorganic lead‐free Cs 3 Cu 2 I 5 perovskite materials has garnered significant attention due to their non‐toxic nature and unique optoelectronic properties, particularly in the field of X‐ray detection. However, the stability of perovskites remains a major concern for their optical applications. In this study, a highly stable Cs 3 Cu 2 I 5 ‐in‐glass composite (Cs 3 Cu 2 I 5 @Borosilicate) is fabricated by spark plasma sintering (SPS), a rapid and low‐temperature sintering process. The Cs 3 Cu 2 I 5 @Borosilicate composite exhibits strong photoluminescence even after prolonged immersion in various polar solvents, whereas Cs 3 Cu 2 I 5 perovskite loses its photoluminescence within seconds. Moreover, the Cs 3 Cu 2 I 5 @Borosilicate composite demonstrates robust radio‐luminescence under X‐ray irradiation, and its potential as a scintillator material is validated through prototype X‐ray imaging with a high spatial resolution (≈7 lp mm −1 ). This innovative composite material holds immense potential for scintillation applications and represents a promising approach for encapsulating perovskites in a transparent amorphous medium.