Sol-gel processed Ce^(3+), Tb^(3+) codoped white emitting phosphors in Sr_2Al_2SiO_7

摘要

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 microstruc- ture 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.