Exploration of metaphosphate glasses dispersed with Eu-doped SiAlON for white LED applications

• Glass-phosphor composites were obtained for white LED by melting.
• The prepared glasses had similar structures composed of long chain networks.
• Color of the composite depended on the glass composition and phosphor concentration.
• Thickness of the composite affected the color of the composite.
• The BaP glass composite was the most suitable for white LEDs.

Ca-α-SiAlON:Eu2+ oxynitride phosphors are typical luminescent materials with a high thermal tolerance. A series of metaphosphate glass samples (50MO–50P2O5; mol%, M = Zn, Ca, and Ba) were prepared in order to investigate their ability to disperse Ca-α-SiAlON:Eu2+ phosphor powders. The glass structures of all of the samples were formed using Q2 species and composed in long chain networks by investigation of the NMR and Raman spectra. In the glass samples, SiAlON was dispersed until reaching 5 or 6 mass%. The color due to irradiation by a blue LED (wavelength of 450 nm) depended on the glass composition, concentration of SiAlON, and thickness of the composite. Regarding the glass formation and quantum efficiency, the BaP glass with between 3 and 4 mass% SiAlON composite was determined to be the most suitable for use as a host material for white LEDs.