Dual-Function Organic Emitters for Plastic Scintillators Enabled by Integration of Photocatalytic Controlled Radical Polymerization and Sensitive X-Ray Detection

Organic scintillators are attractive for X-ray detection and imaging because of their solution processability and compatibility with large-area fabrication. However, their development is limited by the trade-off between X-ray attenuation and photoluminescence quantum yield (PLQY), as well as by the lack of mild fabrication methods for plastic scintillator screens. Herein, we report a brominated donoracceptor–donor molecular platform with hybridized local and charge-transfer (HLCT) character that addresses both challenges. Peripheral bromination of a benzo[c][1,2,5]oxadiazole-based scaffold produces a pronounced anti-heavy-atom effect, simultaneously enhancing X-ray attenuation and PLQY. This strategy is extended through chalcogen substitution to afford BOTBr, BTTBr, and BSeTBr, among which BTTBr shows the best overall performance, delivering a PLQY of 77%, a light yield of 37,851 photons MeV-1, and a detection limit of 54 nGy s-1. Notably, BTTBr also acts as a photocatalyst for photoinitiated atom transfer radical polymerization (PhotoATRP), enabling the in situ fabrication of transparent and uniform poly(methyl methacrylate) scintillator screens under mild conditions. The resulting screens afford high-resolution X-ray imaging with a spatial resolution of 13.2 lp mm-1. This work establishes an anti-heavy-atom-effect strategy for dual-functional scintillatorphotocatalyst materials and provides a light-driven route to integrated plasticscintillator fabrication.