离子取代与晶格调控对YAG:Ce3+荧光粉发光性质的影响

Compared with tranditional incandescent lamp and fluorescent lamp, white light-emitting diodes (WLEDs) have greatly promising application in the field of lighting and display due to their advantages such as high efficiency, energy conservation, environmental protection. As the luminescence materials have a great influence on the device performance of WLEDs, such as the luminous efficiency, color rendering index, and thermal stability,the luminescent performance of phosphors plays a key role on the development of WLEDs. Aiming at the problems of low color rendering index of commercial YAG:Ce3+ and the difficulty to synthesize oxynitride, this project will try to synthesize a series of solid-solution phosphors (Y3Al5-2xMgx(Si/Ge)xO12:Ce3+, Y3Al5-zSizO12-zNz:Ce3+, Y3-nMnAl2Al3-nSinO12:Ce3+, where M represents Mg2+, Ca2+, Sr2+ or Mn2+,0≤x≤2, 0≤z≤0.5, 0≤n≤3) with garnet structure by neighboring-ion site substitution and nitriding under normal pressure. Moreover, the influence of the ion substitution and crystal structure variation, especially the variation of microstructure on the photoluminescence properties of Ce3+ will be investigated in depth, and the luminescent mechanisms related with crystal structure will be proposed in this project. The research work for the corresponding application in WLEDs device would be carried out.

白光LED因具有高效、节能、环保等优点，成为当前照明领域的研究热点。其中荧光粉对白光LED器件的性能如发光效率，显色指数等有很大影响,所以荧光粉性能的优劣对白光LED技术的发展起着关键作用。本项目针对传统黄色YAG:Ce3+荧光粉显色性较低及硅基氮氧化物难以合成等问题，采用临近离子取代与常压低温氮化的技术手段调节YAG的结构组份，得到同时具备石榴石结构，且颗粒尺寸分布均匀的系列固溶体相(Y3Al5-2xMgx(Si/Ge)xO12:Ce3+,Y3Al5-zSizO12-zNz:Ce3+,Y3-nMnAl2Al3-nSinO12:Ce3+,M = Mg2+/Ca2+/Sr2+/Mn2+, 0≤x≤2, 0≤z≤0.5, 0≤n≤3)荧光粉，研究离子取代，结构改变特别是微结构的改变对Ce3+离子发光性质的影响，阐明结构相关的发光机理；并开展在白光LED器件应用中的研究工作。

白光LED因具有高效、节能、环保等优点，成为当前照明领域的研究热点。其中荧光粉对白光LED器件的性能如发光效率，显色指数等有很大影响,所以荧光粉性能的优劣对白光LED技术的发展起着关键作用。本项目针对传统黄色YAG:Ce3+荧光粉显色性较低及硅基氮氧化物难以合成等问题，一方面采用软化学方法（溶胶凝胶、水热）结合氨气氮化在常压较低温度下合成氮氧化物材料，在一定程度上实现材料的控制合成；另一方面利用能量传递，离子取代等方法，探讨改善材料发光效率、热猝灭性等应用性能的有效途径；并结合晶体场光谱理论，从理论上讨论基质成分与结构改变时对激活离子发光性质的影响，为新材料开发提供依据。同时探索开发新颖高性能荧光粉，以期实现在LED领域的应用。在整个项目执行期间，共计发表SCI论文26篇，参加国内外会议5次，做报告3次，申请发明专利1项，完成了项目的预期研究目标。