Synthesis and photoluminescence properties of NaLaMgWO6:RE3+ (RE = Eu, Sm, Tb) phosphor for white LED application

Single phase of NaLa1-xMgWO6:xRE(3+) (0 < x <= 1) (RE = Eu, Sm, Tb) phosphors were prepared by solid-state reaction method. X-ray diffraction, scanning electron microscopy, the morphology energy-dispersive X-ray spectroscopy, UV-vis diffuse reflectance spectra and photoluminescence were used to characterize the samples. Under the light excitation, NaLaMgWO6:Eu3+, NaLaMgWO6:Sm3+ and NaLaMgWO6:Tb3+, phosphors showed the characteristic emissions of Eu3+ (D-5(0) -> F-7(4,) (3, 2, 1)), Sm3+ ((4)G(5/2) -> GH(5/2,) (7/2,) (9/2)), and Tb3+ (D-5(4) -> F-7(6,) (5, 4, 3)), respectively. The intensity of the red emission for Na(La0.6Eu0.4)MgWO6 is 2.5 times higher than that of (Y0.95Eu0.05)(2)O-3 under blue light irradiation. The quantum efficiencies of the entitled phosphors excited under 394 nm and 464 nm are also investigated and compared with commercial phosphors Y2O3:Eu3+, Sr2Si5N8:Eu2+ and Y(3)A(5)G(12):Ce3+. The results demonstrated NaLaMgWO6:RE3+ phosphors as potential candidates for white light emitting diode pumped by UV or blue chip. (C) 2012 Elsevier Ltd. All rights reserved.