Luminescent properties of Ca-α-SiAlON: Eu2+ phosphors synthesized by gas-pressured sintering

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-α-SiAlON: Eu2+ based yellow and orange oxynitride phosphors with compositions of Ca0.485 Eu0.015 Si9.2 Al2.8 O1.8 N14.2 and Ca0.94 Eu0.06 Si9 Al3 ON15 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°C. The Stokes shift and zero-phonon line was calculated mathematically and estimated from the spectral data. The prepared Ca-α-SiAlON: Eu2+ phosphors showed superior thermal quenching properties compared to commercially used YAG: Ce3+ phosphors. In addition, the activation energies (ΔE) for thermal quenching of the prepared Ca-α-SiAlON: Eu2+ phosphors were determined by Arrhenius fitting.