A novel red emitting Eu3+ doped calcium aluminozincate phosphor for applications in w-LEDs

A novel calcium aluminozincate phosphor doped with Eu3+ ions has been synthesized by conventional solid state reaction method and characterized by using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Diffuse Reflectance Absorbance (DRA) and Spectrofluorophotometer to study the structural, morphological and photoluminescence (PL) properties. All the XRD peaks are matching well with the standard ICDD card confirm that the prepared phosphors consist of single phase orthorhombic structure (Ca3Al4ZnO10) having Pbc2 space group. The PL spectra recorded under near-UV/blue excitations demonstrates a very distinct and intense red emission from all the phosphors. In the present investigation, we found that 2 mol% of Eu3+ ions concentration is optimum in this host to give intense red emission. This result is also in consistent with the CIE chromaticity coordinates measured from the PL spectra of the samples under investigation. The results obtained for the optimized phosphor in the present investigation such as PL and CIE coordinates (x = 0.629 and y = 0.370) are close to the commercial red phosphor Y2O2S: Eu3+ (x = 0.622 and y = 0.351) and also very near to the coordinates specified by National Television Standard Committee (NTSC).