Facilely Fabricated Bright Lead‐Free Perovskite Cs3Cu2I5 Scintillator Film for High‐Definition X‐Ray Imaging

Scintillator is a critical component to detect high‐energy particles or rays, which is widely used in deep space exploration, security inspection, and nondestructive testing and medical diagnosis, such as X‐ray imaging and computed tomography (CT). However, the wider application of traditional inorganic and organic scintillators is limited by the complex operation process or poor adaptability to changeable environment, and there remains a demand to develop green and stable scintillators with high sensitivity and low detection limit. Herein, the one‐step preparation of lead‐free perovskite Cs 3 Cu 2 I 5 scintillator film for high‐definition X‐ray imaging by conventional chemical vapor deposition method is reported. Cs 3 Cu 2 I 5 demonstrates good stability and bright‐blue emission at 445 nm and superhigh photoluminescence quantum yield (85.14%). Importantly, upon X‐ray irradiation, the Cs 3 Cu 2 I 5 perovskite film exhibits light yield (≈39 251 photons MeV −1 ) as high as two times of the commercially available Ce:LuAG single‐crystal scintillator (≈22 000 photons MeV −1 ). Furthermore, the practical demonstration for a bamboo stick and insect specimens illustrates sensitive scintillation response to X‐ray signals with superior linearity and high‐quality images in X‐ray photography and CT. Overall, Cs 3 Cu 2 I 5 film provides nontoxicity, high radioluminescence intensity, and good stability, it can be regarded as a competitive material for X‐ray imaging.