PHOSPHORESCENT DYNAMICS IN SRAL2O4-EU2-CRYSTAL FIBERS(, DY3+ SINGLE)

We report for the first time the growth of activated alkaline earth al uminate single crystals with long persistent phosphorescence. Measurem ents of the phosphorescence and decay dynamics on samples of SrAl2O4 c rystals doped with Eu2+ only and with Eu2+ and Dy3+ indicate that the trapping rate of Dy ions is very fast; the efficiency of trapping is e stimated to be about 40% at room temperature. The decay curve of the a fter-glow is nonexponential, and cannot be explained simply by thermal ly activated detrapping processes. Hole transport may be an important factor in persistent phosphorescence. (C) 1998 Elsevier Science B.V. A ll rights reserved.