Preparation of YAG:Europium Red Phosphors by Spray Pyrolysis Using a Filter-Expansion Aerosol Generator

Abstract

Europium-doped yttrium aluminum garnet (YAG) phosphor particles were prepared from mixed nitrate solutions by the FEAG (filter expansion aerosol generator) process. The crystallinity, morphology, and luminescence of the YAG:Eu particles were investigated. The prepared particles had an amorphous phase, which turned into phase-pure YAG particles after annealing above 1000 degrees C. A cubic-structure YAG phase was formed by the reaction of crystalline Y2O3 and the aluminum component. The prepared particles had spherical morphology. The mean size of the YAG:Eu particles increased from 0.45 to 1.0 mu m when the overall solution concentrations were increased from 0.02 to 1.2 mol/L. The optimum doping concentration of europium for the maximum brightness of phosphor particles was 1.3 at.%. The cathodoluminescence (CL) intensity was strongly affected by the annealing temperatures. The maximum CL value of the particles was 55 cd/m(2).