Highly Stable Mn ²⁺ ‐Doped CsCdCl ₃ Perovskite Nanocrystals for X‐Ray Imaging

ABSTRACT Metal halide perovskite nanocrystals (NCs) have emerged as a new generation of high‐efficiency scintillator luminescent materials due to their unique optoelectronic properties. In this work, we synthesized highly stable cubic‐phase Mn 2+ ‐doped CsCdCl 3 NCs for the first time via the hot injection method. The material exhibits bright orange emission with a photoluminescence quantum yield (PLQY) of 82.7%, surpassing other Mn 2+ doped perovskite nanocrystalline materials. Mn 2+ ‐doped CsCdCl 3 NCs exhibit exceptional stability, retaining their cubic structure at 70°C for 10 h or over 6 months at room temperature. They also maintain > 90% luminescence intensity after 15 days in air or 120 h under 65% RH. The radioluminescence (RL) intensity remains unchanged under X‐ray irradiation at a dose rate of 5.7 mGy·s −1 for 1.5 h, revealing their promising potential for X‐ray radiation detection applications. These NCs also exhibit excellent scintillation performance of 54500 photons MeV −1 light yield, which is about 514% of BGO, and a detection limit as low as 28.97 nGy·s −1 . Furthermore, the fabricated CsCdCl 3 : 0.25Mn 2+ @PMMA film achieved a spatial resolution of 17.5 lp·mm −1 , positioning them as promising candidates for high‐resolution X‐ray imaging.