Enhanced X-ray-excited persistent luminescence in CaF2:Tb3+via interstitial Li+ incorporation

Abstract

We report a strategy to achieve enhanced X-ray-excited persistent luminescence (X-PerL) in CaF₂:Tb³⁺ through the incorporation of interstitial Li⁺ ions. With optimal co-doping of 3% Tb³⁺ and 11% Li⁺, the X-ray-excited optical luminescence (XEOL) intensity is enhanced by 3.3-fold, while the X-PerL intensity is increased by 2.7-fold with prolonged afterglow duration. Flexible scintillator films based on CaF₂:3%Tb³⁺,11%Li⁺ enable high-resolution X-ray imaging (14.3 lp mm⁻¹) in both real-time and time-lapse modes.