Time-resolved luminescence spectroscopy of Eu2+ in BaFCI:Eu2+ X-ray storage phosphor

Photoluminescence (PL) spectra recorded at room temperature (RT) in polycrystalline BaFCI:Eu 2+ X-ray storage phosphor have shown the europium associated luminescences, a broad luminescence band at 385nm (3.22eV) with a 3.3±0.1μs PL lifetime accompanied by a luminescence line at about 368nm (3.37eV). The energy difference ΔE B-L =226cm -1 between the two excited levels from which the europium associated band and line luminescences took place was computed. An additional broad luminescence band at about 425nm (2.92eV) with 0.7±0.1μs PL lifetime has been attributed to the europium luminescence perturbed by an impurity. Time resolved spectroscopy measurements have shown that no other impurity luminescences (like oxygen-vacancy centres) can be observed at RT except the europium associated ones.