Synthesis and characterization of monodisperse yttrium aluminum garnet (YAG) micro-crystals with rhombic dodecahedron

Uniform, monodisperse yttrium aluminum garnet (YAG) rhombic dodecahedron micro-crystals were synthesized using coprecipitation and hydrothermal methods. The Na₂SO₄ as a surfactant was helpful in improving the dispersity of the crystallites and forming well-faceted, micro-sized dodecahedral YAG crystallites. The effect of the reaction time and the solvent has also been studied. The crystal growth mechanism called dissolution/crystallization was determined by analyzing the experimental and simulated results. And the specific well-developed crystal facets in the {110} family have been demonstrated by the theoretical calculation. A higher integrated emission intensity can be achieved for the YAG:Ce crystallites by improving the phase purity, morphology with better developed dodecahedrons, and dispersion. Furthermore, a rather high luminous efficacy (LE = 104.14 lm/W) for the white LED fabricated using the YAG:Ce³⁺ phosphor prepared in this work was realized. The correlation between the crystal growth, morphology and luminescence properties of YAG crystallites has been established, which exhibits a great importance for the synthesis and application of mono-dispersed YAG crystallites.