Photoluminescent properties and Judd-Ofelt analysis of novel Na0.5Sr0.25NbO3: Eu3+ red phosphor with high quantum efficiency

We report on a novel NaooSr(0.25)NbO(3): Eu3+ phosphor fabricated by a molten salt synthesis method with the potential application in white light-emitting diodes (WLEDs) as a red phosphor. The crystal structure, morphology, emission/excitation spectra, as well as decay curves were characterized with X-ray diffraction, Scanning Electron Microscope and photoluminescence spectrometer, respectively. Concentration quenching occurred when the concentration of Eu3+ was beyond 5 mol% due to the dipole-dipole interaction by non-radiative energy transfer. Besides, the effect of the crystal field surrounding the Eu3+ ions on the luminescent performance under 396 nm and 466 nm excitions has been investigated by the Judd-Ofelt theory. The result indicated that the quantum efficiency of the phosphor was 62.65% excited by 466 nm, which was superior to 41.43% excited by 396 mn. The optimal sample's CIE coordinates were (0.6471, 0.3504) with the color purity of 97%, showing a potential application in (WLEDs) illumination field.