Luminescent Bi-containing Phosphate-Molybdate Glass-Ceramics

Abstract

The procedure of preparation of luminescent glass-ceramics consisting of 37.09K2 O-31.79$\mathrm{P}_{2}\mathrm{O}_{5-}$25.43Mo$\mathrm{O}_{3-}$5.69B$\mathrm{i}_{2}\mathrm{O}_{3}$ glass and KB$\mathrm{i}_{0.95}$Eu(MoO4)2 was described. The results of powder X-ray diffraction, scanning electron microscopy, thermo-gravimetrical analysis and luminescence spectroscopy studies have been discussed from viewpoint of the studied materials application in white light emitting diodes. It was found that glass-ceramics consist mainly of amorphous phase with inclusion of potassium bismuth molybdate micro/nanocrystals. The glass transition temperatures were determined as 333, 340 and 327°C for initial glass, Eu-doped glass and glass-ceramics studied, respectively. The initial glass reveals wide luminescence band that lies in 500 -- 750 nm spectral range under excitation at 473 nm at room temperature. Europium-doped glass and glass-ceramics samples mainly reveal luminescence bands of $f-f$ transitions in $\mathrm{E}\mathrm{u}^{3+}$ ions. The broadening of $\mathrm{E}\mathrm{u}^{3+}$ emission bands in glassceramic samples was ascribed to migration of some rare-earth ions from crystalline component into glass host.