基于蓝光GaN芯片的荧光粉转换的白光LED可望成为下一代照明光源。为制备暖白光LED，亟待开发新型全色白光荧光粉。以黄光YAG:Ce为转换荧光粉的白光LED技术是发展最成熟的一种, 但其红光成分不足，显色性差；本项目拟以其为基体进行SiO2表面包覆，同时包埋染料罗丹明、碳菁素等，研制一种非混合型、红色成分丰富的核壳杂化单一荧光粉；用染料转换部分内核黄绿光而产生宽带红光，获得与现行商用LED技术兼容性较好且有丰富红光发射和较高光热稳定性的YAG:Ce核/SiO2壳杂化荧光粉，并封装白光LED；拟选择合适的湿化学方法制备亚微米尺度，发光效率高，易于表面包覆的近球形YAG:Ce荧光粉。探索实验方法和条件实现对湿法制备的小尺寸和商用大尺寸的YAG:Ce荧光粉的可控包覆和染料包埋，探索有效的染料嵌入浓度和抑制染料因光辐照和加热而漂白的最佳壳层厚度，为蓝光LED用高显色性白光荧光粉的开发提供实验依据。

Phosphors-converted white LED, based on blue GaN chips, is expected to become the next generation of lighting source. Aiming at preparing warm white LED, it is desirable to develop a new type of highly efficient, full color white-emitting phosphors based on blue LED chips. The white LED technique involving yellow YAG:Ce3+ converted phosphors was developed earliest, and is currently the ripest one, however, its red emission is not enough, as a consequence, the converted white light has low color-rendering index. This project aims to develop an unblended single LED phosphors with rich red emission, which will select YAG:Ce3+ as a mother material and then prepare the core/shell hybrid composite (YAG:Ce3+@dyes@SiO2) via SiO2 coating and simulatneous embedding of fluorescent dyes such as Rhodamine and Indodicarbocyanine. Fluorescent dyes are employed to convert partly the green and yellow irradiations emitted by YAG:Ce3+ core and produce the broadband red-rich emissions; It is expected to get one kind of dye-embeded core (YAG:Ce3+)/shell (SiO2) hybrid phosphors with red-rich emissions as well as high stability against photo-irradiating and heating, and with good compatibility to current LED technique commercially available. Such phosphors will be encapsulated for warm white LED. For easier surface coating, an appropriate solution-processed method will be developed to synthesize nearly spherical YAG:Ce3+ phosphors with submicrometer size and bright luminescence. Some definite experimental methods and conditions need to be explored for controlled surface coating and embedding of organic dyes on both the small-sized laboratory-available and big-sized commercially available YAG:Ce3+ phosphors; As well, effective doping concentration of dyes and optimum thickness of outer shell of SiO2 against the luminescence bleaching induced by photo-irradiating and heating need to be explored. This project is expected to provide experimental evidences for preparing blue-LED-based yellow phosphors for high color rendering index and full color white light.