Photoluminescence and photostimulated luminescence in the X-ray storage phosphor BaBr2 doped with cerium

摘要

In orthorhombic BaBr2:Ce3+ two kinds of luminescence bands at room temperature have been attributed to charge-compensated Ce3+ centres. One type was associated with potassium (or some other monovalent cation) on a neighbouring Ba site and another one associated with an unidentified defect. A third kind of emission, observed only as low temperature photoluminescence (PL), is ascribed to isolated Ce3+ ions. The charge-compensated Ce3+ complexes are active both in PL and photostimulated luminescence (PSL) following X-ray irradiation. The PSL is nearly as efficient as in the case of the commercially used X-ray storage phosphor BaFBr:Eu2+. The X-ray induced electrons are trapped in F-type centres whose band position is characteristic for the nearby Ce complex. As shown by the fingerprint character of the PSL itself, the hole partner in the recombination is also associated or identical with the same Ce complex. (C) 2003 Elsevier Ltd. All rights reserved.