Eu‐Doped β‐SiAlON Phosphors: Template‐Assistant Low Temperature Synthesis, Dual Band Emission, and High‐Thermal Stability

Abstract

A hard template route has been successfully developed for synthesis of β‐SiAlON:Eu phosphors at low temperatures. The synthesis utilizes mesoporous silica (SBA‐15) skeleton as an active Si source, combined with the carbothermal reduction and nitridation method. It has been shown that the additional driving force from high surface area and porosity of SBA‐15 enables β‐SiAlON:Eu (with compositions of Si6−zAlz−xOz+xN8−z−x: xEu, x = 0.010–0.200 and z = 1.000) phosphors to be formed as a dominant phase at low temperature of 1400°C. The resultant β‐SiAlON:Eu phosphor powders exhibit a typical rod‐like morphology and a well dispersed state. By tailoring the Eu2+ concentration in the phosphors, a continuous change in emission band can be realized, that is a blue emission dominated for low Eu2+ concentrations and a green emission dominated for high Eu2+ doping concentrations. Furthermore, the resultant phosphors exhibit a small thermal quenching up to high temperature of 250°C. Therefore, the developed method is beneficial to synthesize LED phosphors of oxynitride systems at lower temperatures.