The <i>h</i>-BN Protective Method Used for the Synthesis of Highly Uniform Spherical Si-Based Oxynitride Phosphors

Abstract

The highly uniform spherical Si-based oxynitride core-shell structured phosphors with narrow size distribution and non-aggregation were successfully fabricated by the h-BN protective method for the first time. Firstly, the raw metallic ions (rare earth and alkaline earth ions) were coated on the surface of SiO2 templates via the urea homogeneous precipitation method. Then the core-shell precursor particles were coated with a H3BO3 layer, which was transformed to a h-BN protective film in the reduction condition. At last, the spherical core-shell structured oxynitride phosphors were synthesized through a gas reduction and nitridation method. The as-received phosphors show excellent luminescence properties due to the 4f65d-4f7 transition of Eu2+ under the excitation of UV and blue lights. The homogeneous spherical phosphors are expected to have excellent dispersing and coating properties, which are very important for LED and PDP applications.