Radiation induced defects in polycrystalline pure and Ce3+ doped Sr2B5O9Br storage phosphors were investigated by using electron paramagnetic resonance and optical absorption methods. The electron paramagnetic resonance of irradiated pure Sr2B5O9Br represented 2 overlapping spectra in the 335–340mT range from paramagnetic electron and hole trapping centres, which were stable at room temperature. These centres were attributed to F(Br-) and OBr- centres, i.e. an electron trapped in a Br vacancy and a hole trapped on an O ion at a Br site. The 1s → 2p transitions of F(Br-) centres caused the optical absorption band at 560nm. Another observed absorption band at 365nm was attributed to the transitions of O- centres. Thus electron and hole trapping in pure Sr2B5O9Br occurred in VBr and OBr2- aggregates, which were created during the synthesis. Electron paramagnetic resonance  and optical absorption measurements on Ce3+ doped Sr2B5O9Br revealed similar defects as in pure material. It was very likely that the same defects took part in the processes of thermally and photo-stimulated luminescence.

Radiation-Induced Defects in Sr2B5O9Br:Ce3+ Storage Phosphor. A.V.Sidorenko, A.J.J.Bos, P.Dorenbos, C.W.E.van Eijk, P.A.Rodnyi, I.V.Berezovskaya, V.P.Dotsenko, O.Guillot-Noel, D.Gourier: Journal of Physics - Condensed Matter, 2004, 16[23], 4131-8