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, AIN and Eu2O3 at 1700-1900 degrees C for 3h under a nitrogen pressure of 0.5 MPa. Single-phase 15R-sialon:Eu2+ phosphors could be obtained by controlling Eu concentration at 1800-1850 degrees 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. (C) 2010 Elsevier B.V. All rights reserved.