Uranyl organic complexes (UOCs) commonly exhibit low photoluminescence quantum yield (PLQY) due to their high nonradiative transition rate (knr) caused by jammed ligand-to-uranyl energy transfer as well as vibrational energy dissipation derived from the flexible structure. Herein, we proposed a noncoordinating substituent modulation strategy to regulate the electronic structure and the stacking mode of UOCs. An over 60-fold reduction in knr boosts the PLQY from 0.24% (UOC 1) to 42.8% (UOC 3), the highest value in heteroleptic UOCs. With this benefit, UOC 3 emerges as a top-performing uranium-based scintillator for sensitive X-ray detection. Furthermore, a uniform and flexible scintillator film prepared from UOC 3 exhibited a high spatial resolution of approximately 5 lp mm–1 for efficient X-ray imaging.
Yang et al. (2026) studied this question.