Synthesis of YAG phosphor particles with excellent morphology by solid state reaction

Cerium doped yttrium aluminum garnet (YAG:Ce) has been chosen as WLED phosphors for its appropriate spectral property. However, YAG powders synthesized by several methods do not satisfy commercial requirements in mobility, size distribution, luminescent intensity, etc. With flux added in the synthesis, well-shaped crystallites can nucleate and grow in the wetted micro domains. High temperature compensates the adverse effect of intermediate product on particle size. The final products are phosphor powders composed of uniformly distributed large particles. Preferred orientation in the XRD patterns confirms that the isolated particles are single crystals other than agglomeration of fine grains. This kind of phosphors has a better performance in WLED devices. This work will improve the commercial production of WLED phosphors.

► YAG phosphor powders with excellent morphology have been successfully synthesized.
► Flux plays a critical role to the good morphology.
► An intermediate YAlO3 phase appears and limits the particle size.