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

The development of all‐inorganic lead‐free Cs3Cu2I5 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 Cs3Cu2I5‐in‐glass composite (Cs3Cu2I5@Borosilicate) is fabricated by spark plasma sintering (SPS), a rapid and low‐temperature sintering process. The Cs3Cu2I5@Borosilicate composite exhibits strong photoluminescence even after prolonged immersion in various polar solvents, whereas Cs3Cu2I5 perovskite loses its photoluminescence within seconds. Moreover, the Cs3Cu2I5@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. Cs3Cu2I5@Borosilicate composites with excellent stability and optical properties are prepared by embedding Cs3Cu2I5 MHPs into inorganic borosilicate glass using SPS. The prototype X‐ray imaging system verified that the Cs3Cu2I5@Borosilicate composite is a potential scintillator material. This work presents a promising strategy for encapsulating perovskites in a transparent amorphous medium.