Halogenated Organic Laser Emitters for X-ray Imaging

Organic laser materials, leveraging their inherent high photoluminescence efficiency and ultrashort radiative lifetime, exhibit efficient singlet exciton radiation, making them promising building blocks for ultrafast scintillators. Herein, we propose a nonmacrocyclic cocrystal engineering strategy to address the long-standing trade-off between heavy-atom-enhanced X-ray absorption and fluorescence quenching. By employing a sterically hindered distyrylbenzene (DSB) derivative as a host to encapsulate halogenated terphenyl guests, we construct cavity-adaptive cocrystals (CACs) with laser emission characteristics, achieving synergistic optimization of high X-ray absorption and ultrafast radioluminescence. The best-performing dibrominated CAC microribbons (MRs) exhibit an ultralow detection limit (71.12 nGy/s), high spatial resolution (17 lp/mm), and rapid X-ray response. This work demonstrates that the CACs, guided by a host/guest functional separation principle, offer a versatile platform for developing high-performance, ultrafast organic scintillators, with transformative potential for real-time medical imaging.