Enhanced White Luminescence in Mixed-Valence Eu-Doped BaAl₂Si₂O₈Glass Ceramics for W-LEDs

Eu 3+ and Eu 2+ co-doped aluminosilicate glass and glass ceramics containing BaAl 2 Si 2 O 8 were prepared by melt-quenching technique in air and their luminescent properties were investigated by excitation, emission spectra and lifetime measurement. Intensities of Eu 3+ and Eu 2+ emissions in glass ceramics were enhanced by about 9 and 20 times compared to that in precursor glass, respectively. More interesting, under 380 nm excitation, a perfect white light with chromaticity coordinates (X = 0.333, Y = 0.307) was achieved for glass ceramics by combining intense red emission of Eu 3+ with broad blue-green emission of Eu 2+ . Our results indicate that mixed-valence Eu-doped BaAl 2 Si 2 O 8 glass ceramics may be used as potential phosphors for W-LEDs.