ABSTRACT The structural tunability and photophysical richness of metal halides make them ideal for exploring next‐generation X‐ray scintillators. Although numerous candidates have been reported in recent years, their commercial viability remains to be rigorously demonstrated. Among them, the high‐density all‐inorganic low‐dimensional copper halide Cs 3 Cu 2 I 5 with a soft lattice and pronounced electron–phonon coupling, readily generates a self‐trapped exciton and thus delivers efficient, self‐absorption‐free emission. In this work, we further modified the scintillation performance of Cs 3 Cu 2 I 5 by Mn 2 + incorporation. The optimized composition delivers 1.35 times the relative light output of CsI: Tl, with a detection limit down to 33.1 nGy s −1 . Besides, the copper halide scintillator possesses negligible afterglow and a fast X‐ray excitation decay time of 46.4 µs. More importantly, the copper halide scintillator exhibits exceptional light output, which is ∼18% higher than that of a commercial imaging scintillator (Carestream Min‐R 2190), through detector‐level determination. We demonstrate a previously unexplored implementation of a powder‐based copper halide scintillator in a linear‐array detector, achieving a spatial resolution of 1.1 lp/mm and showing strong potential for enhanced security inspection applications.
Zhou et al. (2026) studied this question.