Luminescence properties of Eu(3)(+)-doped Na3Gd(PO4)2 red-emitting nanophosphors for LEDs

Eu(3+)-doped Na3Gd(PO4)2 phosphors were synthesized by the modified citrate gel combustion technique. From the XRD pattern, structure of the compound was found to be orthorhombic with a particle size of 10-20nm. The emission spectra revealed that the Na3Gd(PO4)2:Eu(3+) phosphors can be excited effectively by 394nm pump wavelength. From the concentration dependent photoluminescence studies, the optimum concentration for efficient luminescence of Eu(3+) ions in Na3Gd(PO4)2 phosphor has been found to be 1.5mol%. Decay curves of the (5)D0 level of Eu(3+) ions were recorded by monitoring the emission at 596nm corresponding to (5)D0→(7)F1 transition and are found to be single exponential for all the concentrations. The chromaticity properties for different concentrations of Na3Gd(PO4)2:Eu(3+) nanophosphors were calculated from emission spectra and analyzed in the frame work of CIE color diagram.