Synthesis of high-brightness sub-micrometer y₂O₂S red phosphor powders by complex homogeneous precipitation method

High-brightness Y₂O₂S red phosphor powders with sub-micrometer particle size were prepared by complex homogeneous precipitation method employing hydrolysis of urea in water solutions of various diols. Sulfurization was carried out by annealing of the obtained powders at 700-1200 °C in the presence of Na₂CO₃-S mixture. Despite the small particle size, the luminescence intensity for most of the samples was comparable with one of the best available commercial Y₂O₂S phosphors, while Y₂O₂S samples doped with Eu and a small amount of Tb were superior to the commercial reference.