Effects of preparation conditions in the spray pyrolysis on the characteristics of Ca₈Mg(SiO₄)₄ Cl₂:Eu²⁺ phosphor

In spray pyrolysis, the effects of the preparation temperature, flow rate of the carrier gas and concentration of the spray solution on characteristics such as the morphology, size, and emission intensity of Ca₈Mg(SiO₄)₄ Cl₂:Eu²⁺ phosphor powders under long-wavelength ultraviolet light were investigated. The phosphor powders obtained post-treatment had a range of micron sizes with regular morphologies. However, the composition, crystal structure and photoliminescence intensity of the phosphor powders were affected by the preparation conditions of the precursor powders. The Ca₈Mg (SiO₄)₄Cl₂:Eu²⁺ phosphor powders prepared at temperatures that were lower and higher than 700°C had low photoluminescence intensities due to deficiencies related to the of Cl component. The phosphor powders with the deficient C1 component had impurity peaks of Ca₂SiO₄. The optimum flow rates of the carrier gas in the preparation of the Ca₈Mg(SiO₄)₄ Cl₂:Eu²⁺ phosphor powders with high photoluminescence intensities and regular morphologies were between 40 and 60 l/minute. Phosphor powders prepared from a spray solution above 0.5 M had regular morphologies and high photoluminescence intensities.