Controlled Synthesis and Application of α-Al2O3 for Lu3Al5O12: Ce3+ Green Spherical Phosphors

α-Al2O3 powders with different morphologies, namely fibrous, sheet-like, and spherical, were prepared by the hydrothermal-thermolysis method. Subsequently, polycrystalline, transparent cerium doped lutetium aluminum garnet (Lu3Al5O12:Ce3+) green phosphors were synthesized by high temperature solid-state method using commercial lutetium(III) oxide, cerium(III) oxide, and as-prepared Al2O3 powders with different morphologies. The phases, morphologies, and photoluminescent properties of the prepared phosphors were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), and photoluminescence spectroscopy(PL). Moreover, the influences of the morphologies of α-Al2O3 on the types of crystal structure, morphologies, and photoluminescent properties of LuAG:Ce3+ green phosphors were investigated. The results indicated that the morphologies and particle sizes of the α-Al2O3 powders could be controlled by the additives and parameters. Notably, the spherical α-Al2O3 powders with good dispersibility were found to be the excellent base materials of LuAG:Ce3+ green phosphors for white light emitting diodes.