Probing structural defects and X-ray induced persistent luminescence mechanisms on rare earth-doped strontium sulfide materials

. X-ray absorption near edge structure (XANES) spectra revealed the mixed-valence nature of Ce in SrS:Ce and SrS:Eu,Ce materials, and also that X-ray irradiation triggers complex charge transfer processes. The X-ray excited optical luminescence (XEOL) results showed that co-doped samples exhibited longer persistent luminescence decay times than their single-doped counterparts due to the increased number of defects. These findings provide new insights into the interplay between crystal defects and persistent luminescence in X-ray-activated phosphors, contributing to the design of more efficient materials for applications such as medical imaging, optical information storage, and industrial sensing.