Abstract
The oxynitride phosphor Ca-α-SiAlON:Eu2+ has a high thermal tolerance. A series of sodium borosilicate glasses [xNa2O–(60 − x)B2O3–40SiO2, mol %, x = 2–40] was prepared to investigate their ability to host the Ca-α-SiAlON:Eu2+ phosphor powder. The glass-SiAlON phosphor composites, which can emit yellow light when irradiated with blue light (wavelength = 450 nm), were successfully fabricated when the re-melting temperature was 1000 or 1100°C. The chromaticity of the composites, which was estimated from photoluminescence spectra, changed from blue to yellow with increasing SiAlON concentration and sample thickness. This indicates that white light could be generated by controlling the SiAlON concentration and sample thickness. In particular, the 3-mm-thick 10Na2O–50B2O3–40SiO2 glass with a 2 mass % of phosphor generated near-white light. The quantum efficiency of the composites increased with increasing SiAlON concentration and reached a similar value to that of the phosphor powder, and increased as the Na2O concentration of the glass decreased.
