YAG phosphor with spatially separated luminescence centers†
Abstract
A micron size YAG:Ce/YAG:Cr core–shell structure was designed and accomplished via the urea homogeneous precipitation method using the YAG:Ce spherical core as the introduced second phase. A well dispersed gel like encapsulation structure can be achieved before the formation of YAG:Ce/YAG:Cr core–shell particles via a calcination process. As prepared YAG:Ce/YAG:Cr particles can emit a broad range of photons from 500 to 750 nm with excitation light of 433 nm. A schematic illustration showing the mechanism of excitation–emission of the core–shell particles is presented. The integral spectra are composed of three parts: emission photons of YAG:Cr, YAG:Ce, and emission light of YAG:Cr excited by the emission photons of the YAG:Ce core according to the proposed mechanism. The method accomplished in this work can significantly improve the exploration of full spectrum luminescent powder synthesis and spectra designation.