Synthesis, structure and photoluminescence properties of fine yellow-orange Ca-α-SiAlON: Eu2+ phosphors

Yellow-orange oxynitride Ca-α-SiAlON: Eu2+ phosphors with the compositions of Ca0.8Si9.2Al2.8O1.2N14.8: xEu2+ (x = 0–0.24) were obtained via carbothermal reduction and nitridation method. Crystallographic parameters of the refinement structure with triclinic space group P31c (159) were obtained by XRD refinement as a = b = 7.8859(3) Å, c = 5.7336(2) Å, V = 308.7915(3) Å3, Z = 1. The resulting phosphors can absorb light in the range of 300–500 nm efficiently and show a single intense broad emission band in the wavelength range of 500–700 nm with maximum intensity at 580–601 nm. The chromaticity coordinates of the synthesized Ca-α-SiAlON: Eu2+ phosphors can be tailored by simply controlling the activator concentration. All the results show that Ca-α-SiAlON: Eu2+ phosphors can be a candidate for warm white LEDs.

► Powder of Ca-α-SiAlON: Eu2+ have been prepared at 1600 °C under atmospheric pressure.
► Results show pure phase and well-crystallized, and the rod-like grains were observed.
► It could be used as a potential candidate for the phosphor-converted white LEDs.