面向功率型白光LED的复合结构荧光陶瓷光谱调制及光提取效率提升研究

项目名称： 面向功率型白光LED的复合结构荧光陶瓷光谱调制及光提取效率提升研究

项目编号： No.51202269

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 无机非金属材料学科

项目作者： 林辉

作者单位： 中国科学院上海光学精密机械研究所

项目金额： 25万元

中文摘要： 用Ce:YAG陶瓷做为白光LED荧光材料可解决将Ce:YAG荧光粉分散于树脂、硅胶等有机材料中所产生的不利散射、色温一致性差、有机材料老化、着色等问题。然而，Ce:YAG荧光陶瓷仍存在由其荧光光谱缺少红光成分而导致色温偏高、显色指数不理想等问题。本课题创新提出复合结构透明荧光陶瓷来改善色温和显色指数，具体为：上层为Ce:YAG黄光荧光陶瓷，下层为Ce,Pr:YAG或Ce,Cr:YAG红光荧光陶瓷，下层红光荧光陶瓷在GaInN蓝光芯片激发下发出的红光可不被吸收而透过Ce:YAG透明荧光陶瓷，上层的Ce:YAG荧光陶瓷在蓝光激发下发出黄光，适当比例红、黄荧光与GaInN芯片的蓝光混合得色温与显色指数改善的白光，由于蓝、黄、红光的强度可以独立调节，所以不影响Ce:YAG的高荧光量子效率。本课题还将利用陶瓷材料易于成型的特点，在陶瓷出光表面引入图形阵列，与蓝光芯片结合，以提高光提取效率，改善散热。

中文关键词： 荧光陶瓷；复合结构；功率型白光LED；光谱调制；光提取效率提升

英文摘要： Light Emitting Diodes (LEDs) are attracting much attention its long life time, high efficiency, environmental friendly property (mercury-free). It becomes a promising candidate to replace the incandescent lamps and the fluorescent lamps in the lighting industry. At present, the typical technology for white light generation is the so called phosphor converted (PC) white LEDs, which uses the combination of a blue LED chip and the Ce:YAG powder phosphors dispersed in the organic matrix, like resin or silica gel. The proper proportional mixture of blue light emitted by the chip and the yellow emission of phosphor excited by the blue light generates white light. However, problems still exist. The heat resistance of the organic matrix is not good. For high power LED chips, the junction temperature increases rapidly during operation. Serious deterioration and degradation of the organic matix will occur. In addition, the aging problems of organic matrix also induces a colour change, which also deteriorates the LEDs`s performance. Turning the Ce:YAG powders into transparent ceramics might be an effective solution to the above mentioned problems. Thus, Ce:YAG phosphors do need to be dispersed in organic matrix. So a stable performance can be expected for high power white LEDs. The advantadges of ceramics also lie in it

英文关键词： ceramic phosphor；composite structure；high power white LEDs；spectra modulation；light extraction efficiency enhancement