Highly Luminescent 0D Antimony‐Based Halides for High‐Resolution Flexible X‐Ray Imaging

ABSTRACT Flexible scintillator screens with high stability and spatial resolution are essential for X‐ray imaging applications. 0D organic–inorganic antimony halides have emerged as promising candidates owing to their superior optical properties and facile synthesis. In this study, high‐quality C 21 H 20 OPSbCl 4 single crystals incorporating dimeric [Sb 2 Cl 8 ] 2− units are synthesized via an evaporation crystallization method. These crystals exhibit intense yellow emission with a photoluminescence quantum yield (PLQY) of 92%. Furthermore, large‐area and flexible C 21 H 20 OPSbCl 4 @PMMA scintillator films are fabricated via a template assembly method, achieving a light yield of 26880 photons/MeV, a detection limit of 160 nGy air /s, and a spatial resolution of up to 12.3 lp/mm. These films exhibit excellent mechanical robustness and retain high‐resolution X‐ray imaging performance even under repeated bending, thereby enabling effective imaging of non‐planar objects. These scintillators further demonstrate remarkable stability under light, thermal, and X‐ray irradiation. This study highlights the promise of organic–inorganic antimony halides as a platform for developing high‐performance flexible scintillators for advanced X‐ray detection.