Design of Phosphor Materials for White Light Source by Control of 4f Electronic Transition Probability of Rare Earth in Solids

随着蓝光发光二极管(LED)的发展、赋能和成本的降低，利用蓝光LED开发白光LED的研究越来越活跃，这推动了人们对高效白光光源取代荧光管的期望。在本项目中，基于上述背景，我们开始了可由蓝光LED和蓝紫激光二极管(LD)激发的新型荧光粉材料的开发及其波长设计、材料制备和光学性能的精确评估。目标材料如下：(I)单晶和固溶体石榴石晶体中Ce~(2+)和Lt；3+&Gt~(2+)离子的广谱可见荧光，它们的波长变化、量子产率、发射光谱与蓝光发光二极管结合的色坐标；(Ii)具有高激发效率和高透明度的石榴石微晶玻璃材料；(Iii)我们首次将重点放在功率-Illumina…中具有405 nm强激发带的Sm~(2+)&Lt；3~+&Gt~(2+)掺杂荧光粉研究了配位场参数、光谱、跃迁几率、量子效率和用积分球测量的量子产率与组成之间的关系。它可以应用于透明玻璃样品的Judd-Ofet分析，并结合寿命数据计算用于估算量子效率的Judd-Ofet参数。对于YAG基微晶玻璃，我们证实了其发光效率与商业白光LED相当，并申请了专利。综上所述，我们对稀土掺杂荧光粉材料进行了系统的研究，包括新型材料的开发，基于4f电子的光学性能的评估，以及作为固态照明器件的器件性能的实验和理论研究。较少

With the development, empowering and cost reduction of blue light-emitting diodes (LED), R＆D of white LED utilizing blue LED have become more and more active, promoting an expectation of highly efficient white light sources that would replace the fluorescent tubes.In this project, based on the above background, we started the research on development of novel phosphor materials that can be excited by blue LEDs and blue-violet laser diode (LD) and on the wavelength design, material fabrication and precise evaluation of their optical properties. Materials as targets are as follows; (I) broad visible fluorescence of Ce^<3+> ions in single crystalline and solid solution garnet crystals, their wavelength variation, quantum yields, color coordinates of emission spectra combined with blue LED, (II) YAG glass ceramic materials which show high excitation efficiency and high transparency, (III) We originally focus on Sm^<3+> doped phosphors with strong excitation band at 405nm, for power-illumina … More tion device with blue-violet LD and developed glass phosphors, investigated the relationship between composition and ligand-field parameters, spectra, transition probability, quantum efficiency and the quantum yields measured with an integrating sphere. It is possible to apply the Judd-Ofelt analyses for transparent glass samples and to calculate the Judd-Ofelt parameters for estimating the quantum efficiency combined with the lifetime data. We have successfully compared the systematic data of semi-theoretical value and experimental values obtained directly from the total flux measurement.For the YAG-based glass ceramics, we confirmed the luminous efficacy comparable to that of commercial white LEDs and proposed a patent.In summary, we conducted systematic studies on rare-earth doped phosphor materials including development of novel materials and evaluation of optical properties based on 4f electrons and of device performances as a solid-state lighting device, both experimentally and theoretically. Less