Halogenated organic glassy scintillators for real-time dynamic X-ray imaging

Purely organic scintillators typically suffer from limited X-ray absorption due to the absence of high atomic number elements, which significantly restricts their radioluminescence (RL) performance and makes dynamic X-ray imaging challenging. To overcome this limitation, halogen atoms were introduced into maleimide-based fluorescent molecules, resulting in a new type of purely organic glassy scintillator with enhanced X-ray absorption and excellent film-forming properties. Compared with the non-halogenated 1-butyl-3,4-diphenyl-1H-pyrrole-2,5-dione (PAM), the brominated derivative 3,4-bis(4-bromophenyl)-1-butyl-1H-pyrrole-2,5-dione (PAM-4Br) exhibits strengthened supramolecular interactions that facilitate the formation of a uniform amorphous glass with high optical transparency (>92% at 550–800 nm). Moreover, PAM-4Br glass demonstrates significantly improved scintillation efficiency through the heavy atom effect of bromine, achieving an RL intensity 110% that of Bi4Ge3O12, an ultrafast response time of 6 ns and a low detection limit of 120 nGy s−1. The resulting high-transparency glassy scintillator screen not only achieves a modulation transfer function (MTF) of 0.28 at 30.0  lp mm−1 under static X-ray imaging, but also successfully enables real-time high-definition dynamic X-ray imaging. It provides a molecular design strategy for high-performance organic glassy scintillators, opening new avenues for advanced X-ray imaging.