Luminescence properties of Eu²⁺ doped Ca-α-SiAlON phosphor

Eu²⁺ Doped Ca-α-SiAlON phosphor have been synthesized from SiO₂, Al₂O₃, CaCO₃, Eu(NO ₃)₃,carbon powders by carbothermal reduction-nitridation (CRN). Using X-ray Diffractometer (XRD) and fluorescent spectrophotometer, the influences of the phase content of the sintered samples after different soaking time at 1390°C and their luminescence properties were studied. The pure Ca-α-SiAlON:Eu²⁺ were prepared at processing temperatures of 1390°C in a holding time of 8 h. Ca-α-SiAlON:Eu²⁺ had high adsorption in the UV-visible spectral region. Two bands were observed in the emission spectrum centered at about 459 and 545 nm exited at 290nm. And two excitation bands located at about 297nm, 300-400nm were observed in the excitation spectrum with monitored at emission wavelength of 469nm or 550nm respectively. The morphology of the samples was examined via SEM, TEM. Ca/Eu co-doped α-SiAlON powders had hollow sphere morphology and it is composed of large numbers of very fine particles of around 30 to 70 nm in diameter. Elemental distribution was investigated using an EDS attached to a scanning electron microscopy (SEM). The sintered sample has a composition commonly seen for α-SiAlON.