Greenish-Yellow Emission from Dy3+-Doped Y2O3 Nanophosphors

Trivalent dysprosium-doped cubic yttrium oxide (Y2O3) nanophosphors were prepared by combustion synthesis using glycine as fuel. The resulting products were characterized by Raman and FT-IR spectra to evaluate the vibrational features of the samples. X-ray diffraction patterns confirmed the formation of a pure cubic phase of Y2O3. The morphology and selective area electron diffraction measurements were carried out using transmission electron microscopy (TEM) and field-emission scanning electron microscopy. From TEM, it is observed that as-prepared particles have average crystallite sizes of around 23 nm. The luminescent and dynamic properties of Y2O3:Dy3+ were examined as a function of temperature and different concentrations of Dy3+. The luminescence study reveals that these phosphors predominantly exhibit greenish-yellow emission due to strong F-4(9/2)-> H-6(13/2) transition at 575 nm and a feeble F-4(9/2)-> H-6(15/2) transition at 488 nm. These results show that the relative luminescence intensity of emission bands changes with different heating temperatures, while the greenish yellow color luminescence as well as Commission International d'Eclairage chromaticity coordinates extracted from the emission spectra were not affected significantly. The strong greenish-yellow emission of Y2O3:Dy3+ phosphor may be useful for applications in solid-state white lamps for general illumination purposes.