Synthesis and photoluminescence of blue-emitting 15R-sialon:Eu2+ phosphors

This paper reports the synthesis and photoluminescence of Eu2+-doped 15R-sialon (SiAl4O2N4) phosphors by firing the powder mixture of Si3N4, Al2O3, AlN and Eu2O3 at 1700–1900 °C for 3 h under a nitrogen pressure of 0.5 MPa. Single-phase 15R-sialon:Eu2+ phosphors could be obtained by controlling Eu concentration at 1800–1850 °C. 15R-sialon:Eu2+ phosphors exhibit blue emission spectra consisting of a broad band with a maximum at about 445 nm and a shoulder at about 465 nm under UV light excitation (250–400 nm). The critical Eu concentration is about 0.5 mol%. The emission spectra and biexponential fluorescence decay suggest that there are two different kinds of N/O coordinations around Eu2+ ions in 15R-sialon. The 15R-sialon:Eu2+ phosphor has small thermal quenching and good chromaticity of x = 0.16 and y = 0.09 for blue emission.