Synthesis and Photoluminescence of β-SiAlON: Eu2+ Blue Phosphor

beta-SiAlON: xEu(2+) (x = 0.02, 0.05, 0.08, 0.10) blue phosphor was synthesized from Si, SiO2, AlN and Eu2O3 powders by metallothermic reduction-nitridation reaction. The influences of firing temperatures on compositions of beta-SiAlON: Eu and photoluminescence were investigated by X-ray diffractometer and fluorescent spectrophotometer, respectively. The results indicate that excitation spectra of beta-SiAlON: Eu2+ consist of two broad bands centered at 290 and 325 nm, and emission spectrum exhibits a single intense broad emission band at similar to 485 nm with half-peak width of 75 nm, which corresponds to 5d-4f transition of Eu2+. The critical concentration (molar fraction) of Eu2+ is 8%. The mechanism analysis suggests that the energy transfer between the Eu2+ -Eu2+ ions occurs and the critical distance is 1.44 nm. Eu2+ occupies the space of tubular channel along [001] direction in the beta-SiAlON crystal.