Synthesis of nanosize Gd₂O₃:Eu phosphor particles with high luminescence efficiency under ultraviolet light

To synthesize nanosize Gd₂O₃:Eu phosphor particles with high luminescence efficiency under UV light, organic additives such as citric acid and ethylene glycol and Na₂CO₃ flux were introduced in large-scale spray pyrolysis. Gd₂O₃:Eu phosphor particles prepared from solution with polymeric precursors such as citric acid and ethylene glycol had micrometer size and spherical shape. However, particles prepared from polymeric precursor solution with Na₂CO₃ flux were nanosize and had nonaggregation characteristics. The as-prepared spherical particles with micrometer size turned into nanosized particles during post-treatment by recrystallization process. The nanosized Gd₂O₃:Eu phosphor particles showed high brightness under 254 nm UV light. The photoluminescence (PL) intensity of the particles prepared from polymeric precursor solution with Na₂CO₃ flux material and post-treated at 1050°C, which are nanosize and have nonaggregation characteristics, was identical to 109% of that of the Y₂O₃:Eu commercial product. The particles post-treated at 1150°C had a PL intensity 34% higher than the commercial product while showing aggregated characteristics.