A Study on the Energy Transfer Between Ce3+ and Tb3+ in BaAl2O4

- BaAl2O4: x%Tb4O7; y%CeO2 (x = 0 and 1; y = 0 ÷ 2) materials are synthesized by the solid phase reaction method. The structural and optical properties of the phosphors are investigated by using X-ray powder diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and photoluminescence measurements. The photoluminescence excitation spectra show that the wavelength of 315 nm is optimal to excite the luminescence of Tb3+ and Ce3+ in the BaAl2O4 material. The photoluminescence spectra of the materials consist of band located from ~350 nm to ~430 nm of Ce3+ and a series of peaks at 489 nm, 543 nm, and 586 nm, corresponding to Tb3+ electronic transitions of 5D4 → 7FJ (j = 6,5,4), respectively. The emission intensity of Tb3+ is significantly enhanced and ones of Ce3+ is reduced when we increase the CeO2 doping concentration and keep the same of Tb4O7 doping concentration. These results clearly indicate the energy transfer from Ce3+ to Tb3+. The energy transfer efficiency reaches up to 71,57% for sample S3