Sol-gel processed Ce 3+, Tb 3+ codoped white emitting phosphors in Sr 2Al 2SiO 7

Abstract

Sr 2Al 2SiO 7:Ce 3+, Tb 3+ white emitting phosphors were fabricated using the sol-gel method. X-Ray Powder Diffraction (XRD) analysis confirmed the formation of Sr 2Al 2SiO 7:Ce 3+, Tb 3+. 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 Ce 3+, Tb 3+-codoped Sr 2Al 2SiO 7 phosphors showed four main emission peaks: one at 414 nm for Ce 3+ and three at 482, 543, and 588 nm for Tb 3+. The emission spectra of the samples with different doping concentrations showed that the Tb 3+ emission was dominant because of the persistent energy transfer from Ce 3+. 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.