Improvement of brightness of Gd₂O₃:Eu phosphor particles using boric acid flux in the spray pyrolysis

Gd₂O₃:Eu phosphor particles of high brightness were directly prepared by the spray pyrolysis from solution with boric acid flux. The particles prepared from solutions with boric acid flux had higher photoluminescence (PL) intensities than that of particles prepared from solution without flux. The particles prepared from the solution of 10 wt% boric acid had the highest PL intensity, which was higher by 43% than that of the particles prepared from solution without flux. The roles of boric acid flux in improving PL intensity of Gd₂O₃:Eu phosphor particles in the spray pyrolysis were to promote crystal growth and to reduce surface defect of particles. They were different from ones in solid state reaction.