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

## TL;DR

A new method creates tunable organic scintillators with improved X-ray imaging performance and no afterglow.

## Contribution

A co-melting strategy is introduced to create color-tunable organic glassy scintillators with enhanced performance.

## Key findings

- Co-melting TPABr with DTPA2F increases Young's modulus by 51% and radioluminescence intensity by 41%.
- The co-melted glass achieves 33,763 photons per MeV light yield and 1.69 ns ultrafast lifetime.
- The material enables 30.0 lp mm−1 X-ray imaging resolution without afterglow artifacts.

## 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 via 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.

A host–guest co-melting strategy enables organic glassy supramolecular scintillators (OGSSs) with efficient energy transfer and stable excitons, achieving tunable emission and afterglow-free dynamic X-ray imaging.