Preparation of CaMgSi₂O₆:Eu blue phosphor particles by spray pyrolysis and its VUV characteristics

Spray pyrolysis was applied to prepare CaMgSi₂O₆:Eu (CMS) blue phosphor particles with high luminescence intensity. The VUV characteristics of CMS particles were optimized in terms of post-treatment temperature, Eu²⁺ concentration and Si content when they were prepared by spray pyrolysis. The luminescence intensity of CMS particles was gradually increased with increasing the post-treatment temperature as long as the melting does not occur. The concentration quenching was observed when the concentration of Eu²⁺ was 1.0 at.%. Also, a red shift in the emission spectrum occurred at the Eu²⁺ concentration of higher than 1.5 at.% due to some increase in the crystal filed around Eu²⁺. Using excess Si was not helpful to improve the photoluminescence intensity of CMS particles when they are prepared by the spray pyrolysis. It was clear that the CMS particles prepared by spray pyrolysis had better thermal stability compared with commercial BAM particles. The emission intensity of the optimized CMS particles was about 97% of BAM particles after the baking at 500 °C although the width of the spectrum was smaller.