This study reports an approach for luminescent properties of Ca-alpha-SiAlON by solid state reaction method using two step firing. The optical properties on the overall composition of the host lattice have been investigated. The fluorescence excitation spectra of all of the nitrogen-rich phosphor powders showed two broad bands centered at about 300 nm and 400 - 475 nm. The first peak was assigned to the absorption of the host lattice and the second to the 4f(7) -> 4f(6)5d(1) absorption of the Eu2+ ions, its senses improved 4f(7) -> 4f(6)5d excitation of Eu2+ ion. The emission intensity increased with increasing the Eu2+ concentration, but only up to a Eu2+ concentration ratio of 0.15. Moreover, the maximum emission peak is observed at m = 2.0 and n = 1.

Keywords: Ca-alpha-SiAlON; White LEDs; Photoluminescence properties