Phosphor layer formed from the Zn₂SiO₄:Mn phosphor particles with spherical shape and fine size

Spherical-shape Zn₂SiO₄:Mn phosphor particles with the mean particle size from submicron to micron sizes were prepared by ultrasonic spray pyrolysis. A droplet separator was introduced to control the size distribution of the phosphor particles with spherical shape. The Zn ₂SiO₄:Mn phosphor particles with 13 mol% doping concentration of manganese have decay time and have photoluminescence intensities comparable with those of the latest commercial product prepared by the solid state reaction method. All the phosphor particles prepared from the solution above 0.2 M have spherical shape and non-aggregation characteristics at the optimized post-treatment conditions for the maximum photoluminescence intensity. The size of the phosphor particles was increased from 0.65 to 1.25 μm as the solution concentration was changed from 0.2 to 2 M. The phosphor particles prepared from the solutions above 0.2 M have photoluminescence intensities comparable with that of the latest commercial product. The phosphor layer formed using the phosphor particles with spherical shape and fine size (1 μm) have uniform surface and dense structure. While the phosphor layer formed using the latest commercial product has rough surface morphology and coarse structure.