Influence of annealing temperature on luminescent properties of Eu3+/V5+ co-doped nanocrystalline Gd2Ti2O7 powders

Nanosized Gd2(1–x)Eu2xTi2O7: yV5+ phosphors were prepared via sol-gel method and characterized with X-ray diffraction, Raman spectroscopy, diffuse reflectance spectra and photoluminescence spectra. Their PL properties were investigated as functions of the Eu3+ doping concentration and annealing temperature. The results indicated that the as-prepared samples showed a strong emission of Eu3+ under the irradiation of 303 nm. For Eu3+-doped Gd2Ti2O7, the orange emission at 586 nm was the strongest, which was corresponding to magnetic dipole transition 5D0–7F1 due to an energy transfer from host, and the optimum concentration for Eu3+ was determined to be 4 mol.%. While for Eu3+/V5+ co-doped Gd2Ti2O7 annealed at 1000 °C, the spectrum was dominated by 615 nm red emissions corresponding to electric dipole transition 5D0–7F2. Additionally, the PL intensity of Eu3+ was enhanced greatly by increasing the annealing temperature. These results are very encouraging for its application in polychromatic displays.