Highly Efficient Stable Luminescent Radical-Based X-ray Scintillator

Stable luminescent radicals are open-shell emitters with unique doublet emission characteristics. This feature makes stable luminescent radicals exhibit widespread application prospects in constructing optical, electrical, and magnetic materials. In this work, a stable luminescent radical-based X-ray scintillator of <b>AuPP-1.0</b> was prepared, which exhibited a high X-ray excited luminescence (XEL) efficiency as well as excellent stability. A mechanism study showed that the heavy atom of Au in <b>AuPP-1.0</b> endowed it with effective absorption of X-rays, and the doublet emission characteristics of <b>AuPP-1.0</b> significantly increased its exciton utilization rate in the radioluminescence process. Moreover, <b>AuPP-1.0</b> has good processability to fabricate a flexible screen for high-quality X-ray imaging, whose resolution can reach 20 LP mm^-1. This work demonstrates that the doublet emission is beneficial for improving the exciton utilization rate of radioluminescence, providing a brand-new strategy for the construction of high-performance X-ray scintillators.