Eu-doped Ca₈Mg(SiO₄)₄Cl₂ phosphor particles prepared by spray pyrolysis from the colloidal spray solution containing ammonium chloride

The green-emitting Ca₈Mg(SiO₄)₄Cl₂:Eu²⁺ phosphor particles were prepared by spray pyrolysis from the colloidal spray solution that contained fumed silica and ammonium chloride. The ammonium chloride was used as the source of chlorine and the flux material. The ratios of the calcium and chlorine components that were dissolved into the spray solution were changed from 1:0.25 to 1:2.5. The phosphor particles prepared from the spray solution with the proper amount of ammonium chloride added to the spray solution had fine sizes and regular morphologies. The phase-pure Ca₈Mg(SiO₄)₄Cl₂:Eu²⁺ phosphor particles were obtained from the spray solution that had a ratio of calcium to chlorine components in the range of 1:0.5 to 1:1.5. The post-treated phosphor particles had a broad excitation wavelength that ranged from 260 to 480 nm, irrespective of the amount of ammonium chloride added to the spray solution. The phosphor particles prepared from the spray solution with a 1:1 ratio of calcium to chlorine had maximum emission intensity under a long-wavelength ultraviolet.