Flexible TADF-based organic X-ray scintillating films for high-resolution imaging†

X-ray scintillators are commonly used, with significant applications in scientific research and daily life. However, most commercial scintillators are based on expensive mechanically rigid inorganic crystalline arrays, which normally bear a long-lived afterglow that reduces the resolution in dynamic X-ray monitoring, while low X-ray absorbance and inefficient exciton utilization are deficiencies associated with traditional organic scintillators. Herein, we report a series of readily obtained pure organic single-component scintillators with halogen-enhanced X-ray absorbance, high fluorescence quantum yield, and short decay time. They can be easily prepared into flexible and transparent scintillating imaging films with a high light yield (approaching 20 000 photons MeV⁻¹) and high resolution (above 20 line pairs per mm) that are among the highest levels for organic scintillators reported thus far.