Eu-doped barium strontium silicate phosphor particles prepared from spray solution containing NH 4Cl flux by spray pyrolysis

Abstract

Eu-doped barium strontium silicate phosphor particles with high photoluminescence intensity under long wavelength ultraviolet were prepared from the spray solution containing NH 4Cl flux by spray pyrolysis. It was found that the addition of NH 4Cl to the spray solution makes it possible to greatly improve the photoluminescence intensity of Ba 1.488Sr 0.5SiO 4:Eu 0.012 phosphor particles under long wavelength ultraviolet of 410 nm. The highest photoluminescence intensity, which was achieved when the NH 4Cl content was 5 wt.%, was about 150% of Ba 1.488Sr 0.5SiO 4:Eu 0.012 particles prepared from the spray solution without flux material at the post-treatment temperature of 1050 °C. The particle size of Ba 1.488Sr 0.5SiO 4:Eu 0.012 phosphor particles were enlarged by using the NH 4Cl flux in the spray solution because of the large grain growth which was identified from the sharpening of the XRD peaks. Adding the NH 4Cl flux into the spray solution was found to lower the optimal post-treatment temperature at which the Ba 1.488Sr 0.5SiO 4:Eu 0.012 phosphor particles are fully crystallized and have the maximum photoluminescence intensity. The phosphor particles prepared from spray solution containing 5 wt.% NH 4Cl flux had the maximum photoluminescence intensity at post-treatment temperature of 1100 °C.