Judd-Ofelt Parameters of Eu3+ and Energy Transfer of Ce3+/Eu3+ in Sr2Al2SiO7 Materials

Sr2Al2SiO7 (SAS) phosphors doped with Eu3+, Ce3+, Ce3+/Eu3+ ions were synthesized by solid-state reaction heating at 1250 degrees C. The phonon energy associated with the F-7(0) -> D-5(2) transition of Eu3+ ions in SAS material was determined by phonon sideband spectra, and vibration energies in the 200-1200 cm(-1) region were measured from the Raman spectra. The asymmetry of the Eu3+ site in the SAS lattice was estimated by the Judd-Ofelt intensity parameters analysis. ohm(lambda) (lambda = 2, 4, 6) intensity parameters determined from emission spectra showed that the introducing of Al2O3 leads to an enhancement of the asymmetry of the Eu3+ surroundings in SAS:Eu3+ materials. Photoluminescence investigation of SAS:Ce3+ (x mol%),Eu3+ (1 mol%) (x = 0, 0.5, 1.0, and 1.5) samples indicated that there is an energy transfer from the sensitizer Ce3+ to the activator Eu3+ in the Sr2Al2SiO7 host lattice.