Transparent Mg-α/β-Sialon:Eu2+ ceramics as a yellow phosphor for pc-WLED

Thin transparent yellow phosphor Sialon ceramics were fabricated by hot pressed sintering method. The fabricated Sialon ceramics were co-doped with Eu2O3 and its yellow luminescence was observed around 570 nm wavelength when excited by UV to blue light spectrum. Furthermore, the white light was observed when thin yellow phosphor Sialon plates were coupled with blue led (455 nm). From XRD patterns, major α-Sialon phase and a minor β-Sialon phase were observed with the addition of Eu2O3. The microstructure revealed that the average grain size was below 500 nm and other phases like AlN polytypoids exists as minor phase. Small amount of Y2O3 addition significantly increased the luminescence intensity as compared to only Eu2O3 addition. Sialon ceramics are generally known as advanced ceramics for high temperature applications; the fabricated transparent yellow Sialon phosphor also exhibits good mechanical properties and suitable for remote phosphor.