Rare-earth-doped oxynitride or nitride compounds have been reported to be photoluminescent and may then serve as new phosphors with good thermal and chemical stabilities. In this work, Ca-alpha-SiAlON:Eu2+ based yellow and orange oxynitride phosphors with compositions of Ca0.485Eu0.015Si9.2Al2.8O1.8N14.2 and Ca0.94Eu0.06Si9Al3ON15 were prepared using the gas-pressured sintering method. The crystallinity and particle morphology of the prepared phosphors were characterized. The temperature dependence of photoluminescence properties was investigated from 25 to 150 degrees C. The Stokes shift and zero-phonon line was calculated mathematically and estimated from the spectral data. The prepared Ca-alpha-SiAlON:Eu2+ phosphors showed superior thermal quenching properties compared to commercially used YAG:Ce3+ phosphors. In addition, the activation energies (Delta E) for thermal quenching of the prepared Ca-alpha-SiAlON:Eu2+ phosphors were determined by Arrhenius fitting. (C) 2008 The Electrochemical Society.