Photoluminescent properties of Dy3+-activated REAl3(BO3)4 (RE=Y, La, Gd) polycrystalline phosphors from hybrid precursors

Dysprosium-activated REAl3(BO3)(4) (RE= Y, La, Gd) polycrystalline phosphors were synthesized via in situ sol-gel process using urea as fuel and metal nitrates as precursors. The uniformity phase of the phosphors was checked by X-ray diffraction (XRD) technique. Scanning electron microscopy (SEM) investigations were carried out to study the surface morphological features and the particle size of the phosphor after heat treatment at 1000 degrees C. The excitation spectra show strong spectral bands in region of 220-450 nm. The characteristic transitions of Dy3+ due to F-4(9/2) -> H-6(15/2) (blue) and F-4(9/2) -> H-6(13/2) (yellow) were observed in the emission spectra and the yellow-to-blue intensity ratio changed with the variety of the doped concentration of Dy3+. The results can be benefit for the white-color luminescent materials. (C) 2007 Elsevier B.V. All rights reserved.