Radiation induced defects in Sr2B5O9Br:Ce3+ storage phosphor

• Published in: Journal of physics. Condensed matter 2004-06, Vol.16 (23), p.4131-4138
• Main Authors: Sidorenko, A V, Bos, A J J, Dorenbos, P, Eijk, C W E van, Rodnyi, P A, Berezovskaya, I V, Dotsenko, V P, Guillot-Noel, O, Gourier, D
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron paramagnetic resonance and relaxation; Exact sciences and technology; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Physics
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/16/23/027

Radiation induced defects in polycrystalline pure and Ce3+ doped Sr2B5O9Br storage phosphors have been investigated using EPR and optical absorption methods. The EPR of irradiated pure Sr2B5O9Br represents two overlapping spectra in the 335-340mT range from paramagnetic electron and hole trapping centres, which are stable at room temperature. These centres are attributed to F(Br-) and O-Br centres, i.e. an electron trapped in a bromine vacancy and a hole trapped on an oxygen ion at a bromine site. The ls RT 2p transitions of F(Br) centres cause the optical absorption band at 560 nm. Another observed absorption band at 365 nm was attributed to the transitions of O- centres. Thus electron and hole trapping in pure Sr2B5O9Br occurs in VBr and Obr2- aggregates, which are created during the synthesis. EPR and optical absorption measurements on Ce3+ doped Sr2B5O9Br reveal similar defects as in pure material. It is very likely that the same defects take part in the processes of thermally and photo-stimulated luminescence.