Generally, the Ca-α-SiAlON:Eu2+ phosphor emits yellow centered at around 580 nm, while the β-SiAlON:Eu2+ phosphor emits green centered at around 530 nm. In this research, multicolor emitting composite phosphors consisting of Ca-α-SiAlON:Eu2+ and β-SiAlON : Eu2+ were in-situ fabricated by gas pressure synthesis. The relationship between photoluminescence characteristics and processing conditions were investigated. Based on the prevailing β-SiAlON phase by compositional design, prolonged soaking time and increased synthesis temperature resulted in the transition of the emission color from dominant yellow to dominant green. Further, improved thermal quenching behavior was achieved for the developed in-situ composite SiAlON phosphor compared to the simple mixture of single phase α- and β-SiAlON phosphor.

Keywords: Nitrides, Oxynitride, Sialon, Phosphor, Composite.