Exploration of Copper Halide Linear‐Array Detector Prototype for Security Checks

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 Cs₃Cu₂I₅ 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 Cs₃Cu₂I₅ by Mn² ⁺ 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.