Facile synthesis of monodisperse YAG:Ce3+ microspheres with high quantum yield via an epoxide-driven sol–gel route

Abstract

Spherical cerium-doped yttrium aluminum garnet (YAG:Ce³⁺) phosphor particles can achieve both higher packing densities and lower scattering of light, and thus make it possible to obtain excellent white-light-emitting diode performance. In this study, monodisperse YAG:Ce³⁺ microspheres have been synthesized through a fast epoxide-driven sol–gel route and subsequent heat treatment under a reducing atmosphere. The spherical morphology was mainly influenced by the phase separation and gelation process, which could be controlled by the ratio of water/ethanol. Pluronic F127 was introduced into the sol–gel system to control the size of the YAG:Ce³⁺ microspheres, which significantly increased the luminescence intensity of the YAG:Ce³⁺ microspheres. The luminescence quantum yield of the 6 mol% Ce³⁺ ion doped YAG microspheres was measured to be more than 90%, which was as high as that of commercial YAG:Ce³⁺ phosphors. This approach may be readily applied to prepare a broad range of rare earth doped microspheres, implying a new route for the preparation of LEDs phosphors with regular shape and high quantum yield.