Sol-gel processed Ce3+, Tb3+ codoped white emitting phosphors in Sr2Al2SiO7

Sr2Al2SiO7:Ce3+, Tb3+ white emitting phosphors were fabricated using the sol-gel method. X-Ray Powder Diffraction (XRD) analysis confirmed the formation of Sr2Al2SiO7:Ce3+, Tb3+. Scanning Electron Microscopy (SEM) observation indicated that the microstructure of the phosphor consisted of regular fine grains with an average size of about 0.5–1 μm. Luminescence properties were analyzed by measuring the photoluminescence spectra. The Ce3+, Tb3+-codoped Sr2Al2SiO7 phosphors showed four main emission peaks: one at 414 nm for Ce3+ and three at 482, 543, and 588 nm for Tb3+. The emission spectra of the samples with different doping concentrations showed that the Tb3+ emission was dominant because of the persistent energy transfer from Ce3+. The decay characteristic was better than that prepared by the solid-state process in the comparable condition. The codoped phosphor displayed long persistent white phosphorescence.