Flexible scintillator films for next-generation X-ray imaging: From materials innovation to conformal detection

Scintillator-mediated indirect X-ray detectors, which transduce high-energy X-ray photons into detectable visible light, underpin critical applications in medical diagnostics, non-destructive imaging, and high-energy physics. Flexible scintillator films represent a transformative advancement for next-generation X-ray imaging, enabling conformal integration biological tissues and complex geometries. The pursuit of solution-processed scintillators with benchmark light yield, ultralow detection limit, and superior mechanical robustness constitutes the primary objective in this field. This review comprehensively analyzes emerging high-performance scintillators, including lanthanide-doped nanocrystals, organic emitters, perovskites, metal-organic frameworks (MOFs), atomically metal clusters, and metal-organic complexes, focusing on strategies to enhance radioluminescence yield, minimize detection limits, and achieve mechanical robustness. We elucidate carrier dynamics from exciton formation to radiative recombination, alongside advanced fabrication paradigms for flexible/stretchable films via polymer encapsulation and intrinsically flexible designs. The resulting devices demonstrate exceptional capabilities in static, dynamic, and multifunctional imaging under ultralow doses. Critical frontiers in radiation stability, artificial intelligence (AI)-accelerated material discovery, and light propagation engineering are outlined to guide future detector development.