New synthetic method and the luminescent properties of green-emitting β-Sialon: Eu2+ phosphors

Eu2+-doped beta-Sialon phosphors with a composition of Eu (x) Si5Al1-x Oz+x N8-z-x (x = 0.05, 0.06, 0.07) were synthesized in a new synthetic route using novel raw materials, such as nano-silicon dioxide (SiO2), nano-carbon (C), and aluminum (Al). This is different from the prevailing method using Si3N4, AlN, and Al2O3 to obtain beta-Sialon phosphors. Compared with the conventional method, lower cost raw materials, simpler pretreatment and a relatively shorter reaction time are achieved. The phosphors show a high purity. All the phosphors exhibit green emission under ultra violet (UV) radiation. A broad band of excitation spectra implies the promising application in UV ray based green light-emitting diode (LED). Chromaticity coordinates of the beta-Sialon: Eu2+ phosphors demonstrate that it is accessible to obtain different green emissions from single phase of Eu2+-doped beta-Sialon through adjusting Eu2O3 concentration. Furthermore, the Eu (x) Si5Al1-x O1 + x N7 - x (x = 0.05) shows a better thermal stability than the commercial green-emitting silicate phosphor. These results indicate a promising prospect for this efficient and economic route in preparing beta-Sialon: Eu2+ phosphors, and the phosphors are a highly promising candidate for LED applications.