Blue-emitting Eu-doped (Sr, Mg)₅(PO₄)₃Cl phosphor particles prepared by spray pyrolysis from the spray solution containing ammonium chloride

Blue-emitting strontium magnesium halophosphate phosphor particles were prepared by spray pyrolysis from the spray solutions with ammonium chloride. The ammonium chloride was used as the source of chlorine and the flux material. The prepared (Sr, Mg)₅(PO₄)₃Cl: Eu²⁺ phosphor particles had regular morphologies and fine sizes. The mean sizes of the (Sr, Mg)₅(PO₄)₃Cl: Eu²⁺ phosphor particles were each 1.2 and 1.9 μn when the ratios of strontium to chlorine components were 1 : 0.5 and 1 : 1. The ratios of strontium to chlorine components in the as-prepared and post-treated particles were each 1 : 0.26 and 1 : 0.21. The (Sr, Mg)₅(PO₄)₃Cl: Eu ²⁺ phosphor particles that were prepared from the spray solution with the ratio of strontium to chlorine components of 1 : 1.5 had the maximum photoluminescence intensity, which was 176% of that of the commercial BaMgAl₁₀O₁₇ : Eu²⁺ phosphor particles under excitation wavelength of 400 nm.