The synthesis and characterization of Dy3+-doped gadolinium oxide phosphors for white light applications

Gd2O3: Dy3+ nanophosphors with doping concentration of 1-3 wt% were prepared by solution combustion method. During the synthesis, citric acid was used as fuel. The synthesized powder was annealed at different temperature. The samples were analysed by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (FE-SEM), Energy dispersive X-ray analysis (EDAX) and photoluminescence (PL) spectrum. The X-ray diffraction pattern confirmed the as synthesized sample showing the mixed phase of hexagonal CGd2O5 and cubic Gd2O3 and it transforms to pure cubic phase of Gd2O3 after annealing at 600°C. Particle size of the phosphors was calculated using Debye Scherrer formula and it was in the range 12nm-39nm. FTIR spectra were measured to evaluate the vibrational features of the sample. Chemical composition of the sample was identified based on EDAX spectra. Morphological observation showed the presence of irregular shaped particles. The photoluminescence measurements were used to explore the emission behaviour of Dy3+ ion activated Gd2O3 phosphors. Photoluminescence emission peak of Gd2O3: Dy3+ samples were observed at 483 run, 571 nm and 677 nm corresponding to the 4F9/2-6H15/2, 4F9/2-6H13/2 and 4F9/26-H11/2 transition respectively. These results indicate that Gd2O3: Dy3+ phosphors may be excellent candidates for the applications of white-light-emitting diodes.