Photoluminescent properties of Dy3+-activated REAl3(BO3)4 (REÂ =Â 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 °C. The excitation spectra show strong spectral bands in region of 220-450 nm. The characteristic transitions of Dy3+ due to 4F9/2 → 6H15/2 (blue) and 4F9/2 → 6H13/2 (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.