Fluorescence spectra of Eu3+-doped lanthanide oxybromide-based powder phosphors

This paper reports the fluorescence properties of a new series of Eu2+-doped powder phosphors based on GdOBr, LaOBr and YOBr. A bright red emission (D-5(0) --> F-7(2)) was observed from all of the powder phosphors under a UV source and this situation was confirmed by fitting the colour coordinates ((X) over bar, (Y) over bar) in the CIE chromaticity diagram. The relative fluorescence intensity ratios for the different measured emission levels were also evaluated in order to examine the host matrix compositional effects on the fluorescence behaviours. The best fluorescent performance was observed from (Gd-0.8, Y-0.2)OBr in the case of a dual lanthanide oxybromide host and from LaOBr in the case of a single lanthanum oxybromide host. For the measured fluorescent transitions, the stimulated emission cross sections (sigma(p)(E) cm(2)) were also calculated. The (Gd-0.8, Y-0.2)OBr, and LaOBr powder phosphors could be suggested as two promising materials, among these studied, for red colour emission and for use in certain electronic systems. (C) 1998 Elsevier Science B.V.