Color-tunable hot-exciton organic glassy supramolecular scintillators enabled by host-guest co-melting.

Abstract

Organic glassy scintillators are promising for radiation detection owing to their low cost and facile processability. However, their performance is often constrained by insufficient X-ray absorption and scintillation quenching during vitrification from a single crystal to glass. Herein, we present a co-melting strategy that integrates a heavy-atom-containing fluorescent host (TPABr) with hot-exciton emitters (DTPA2F, TPE4Br and BTHDMF) to construct color-tunable organic glassy supramolecular scintillators. Notably, the TPABr-DTPA2F glass shows pronounced enhancements over pristine DTPA2F glass, including a ∼51% increase in Young's modulus and a ∼41% boost in radioluminescence intensity. These improvements arise from enhanced X-ray absorption and efficient host-guest energy transfer, ensuring high exciton utilization efficiency in co-melted glass. Besides, supramolecular interactions further provide a rigid microenvironment that suppresses nonradiative decay and stabilizes molecular packing, thereby maintaining high scintillation efficiency. The co-melted glass features an ultrafast lifetime of 1.69 ns and a relative light yield of 33 763 photons per MeV and can be processed into a >12 cm² transparent scintillator screen <i>via</i> comelt-quenching. The resulting screen achieves 30.0 lp mm^-1 static X-ray imaging resolution and eliminates afterglow artifacts in dynamic imaging of vascular models and small biological specimens, demonstrating potential applications for advanced X-ray imaging.