Preparation, characterization, and luminescence properties of BiLaWO:Eu red-emitting phosphors for w-LEDs.

Abstract

Eu-doped bismuth lanthanum tungstate BiLaWO phosphors were synthesized for the first time by a conventional solid-state reaction at 1273K. By powder X-ray diffraction (XRD), the crystal structure of the phosphor was verified, which revealed its single-phase structure. Under the 467nm wavelength excitation, the Eu-doped BiLaWO phosphor powders showed red emission (617nm) that was ascribed to the D→F transitions of Eu. The effects of concentration on luminescence properties indicated that the optimal doping concentration was x=0.50mol. The thermal stability by the emission intensities at various temperatures was verified, and the activation energy (E) was approximately 0.29eV. The luminescence lifetime was analyzed by the decay curve. The chromaticity coordinates of BiLaWO:0.50Eu were x=0.650, y=0.347, which had a high color purity at 99.2%. The phosphors had potential application for white light-emitting diodes.