Crystal structure and luminescence properties ofLiYP4O12:Ce3 + phosphor

Abstract

LiYP4O12 polyphosphatedoped with Ce3 + ions was prepared by the melt solution technique. The crystal structure,interatomic distances, and atom coordination numbers were determined usingx-ray powder diffraction. A study of the spectral–kinetic luminescent propertieswas performed employing excitation with pulsed radiation from a synchrotron(UV–VUV range) and a laboratory x-ray source. The characteristics ofCe3 + luminescence, namely the emission doublet maxima at 3.97 and 3.72 eVand the 4f–5d excitation maxima at 4.20, 5.11, 5.40, 5.65 and 6.55 eV, arediscussed in terms of crystal field splitting in a low-symmetry site of theLiYP4O12 host lattice. Thelocation of the Ce3 + energy levels with respect to the valence and conduction bands of theLiYP4O12 host is estimated from the temperature dependence of the decay time measured forCe3 + 5d–4f luminescence.