Highly Efficient Aggregation Induced Blue‐Emitting Copper(I) Halide Complexes via TADF for OLED and X‐Ray Scintillator

Abstract Developing high‐performance scintillators with high stability, solution processability, high light yield, low detection limit, and high resolution is critical for flexible X‐ray imaging. Nevertheless, achieving an optimal trade‐off among exciton utilization efficiency, X‐ray absorption capacity, and decay lifetime in scintillators remains a significant challenge. Here, the strategy of integrating intense sky‐blue aggregation‐induced emission (AIE) with thermally activated delayed fluorescence (TADF) from novel Cu(I) halide complexes with high quantum efficiency is reported. These materials show excellent radiation resistance and efficient light emission (radioluminescence), reaching an ultralow detection limit of 81.07 nGy air s ‒1 . Their superior performance stems from a combination of strong X‐ray absorption by heavy atom, high exciton utilization through TADF, and suppressed non‐radiative decay from restricted molecular motion. This work demonstrates the potential of hybrid Cu(I) halides with combined AIE and TADF for advanced radiation detection, providing a foundation for cost‐effective and high‐performance scintillators.