화학공학소재연구정보센터
Current Applied Physics, Vol.19, No.5, 621-628, 2019
Characteristic white light emission via down-conversion SrGdAlO4:Dy(3+)nanophosphor
An efficient and cost-effective technique, solution combustion synthesis was used to synthesize Dy3+ doped SrGdAlO4 nanophosphor utilizing urea as a suitable fuel. The tetragonal phase and nano-crystallinity of the synthesized phosphor belonging to I4/mmm space group was confirmed by powder X-ray diffraction (PXRD) and transmission electron microscope (TEM) technique respectively. Various crystal structure parameters and refined atomic positions of host matrix and SrGd0.95Dy0.05 AlO4 nanophosphor were determined by Rietveld refinement. The two intense bands i.e. blue and yellow bands were observed in photoluminescence emission spectrum recorded at 352 nm excitation wavelength, associated to transitions F-4(9/2) -> H-6(15/2) (484 nm) and F-4(9/2) -> H-6(13/2) (575 nm) respectively. Photometric characterizations revealed the emission of white color by the synthesized nanophosphor proving its wide applications in WLEDs (white light emitting diodes). Band gap values calculated using diffuse reflectance spectra (DRS) were found to vary in the range of 5.50 eV-5.59 eV for host and doped lattice system. Keeping in mind, the concentration quenching phenomenon, SrGd0.95Dy0.05AlO4 was considered as optimized nanophosphor for WLEDs.