Eu 2 + -doped Ca-α-SiAlON: A yellow phosphor for white light-emitting diodes

Abstract

In this letter, a yellow oxynitride phosphor $\alpha \text{-}\mathrm{SiAlON}$ with compositions of ${\mathrm{Ca}}_{0.625}{\mathrm{Eu}}_x{\mathrm{Si}}_{0.75-3x}{\mathrm{Al}}_{1.25+3x}{\mathrm{O}}_x{\mathrm{N}}_{16-x}$ ($\mathrm{Ca}\text{-}\alpha \text{-}\mathrm{SiAlON}:\mathrm{Eu}$ , $x=0–25$ ) was prepared by gas pressure sintering. The diffuse reflection spectrum, photoluminescence spectrum, and chromaticity of the powder phosphors were presented. It absorbs light efficiently in the UV–visible spectral region, and shows a single intense broadband emission at $583–603\mathrm{nm}$ . This phosphor may become a good candidate for creating white light, typically warm white light, when coupled to a blue light-emitting diode $\left({\lambda }_{\mathrm{em}}=450\mathrm{nm}\right)$ .