面向激光照明应用的高发光饱和阈值的氮化物荧光薄膜的研究

White laser lighting technology is one of the most effective ways for achieving super-high brightness lighting. Laser phosphors, one of the key materials, dominantly determine its key technical parameters, that is, color rendition, luminous flux, and reliability. As addressed in our previous investigations, the existing phosphors irradiated by laser beams with high flux density suffer from luminescence saturation or even failure, making them unable to be used in laser lighting technologies. But, questions on what controls the saturation and how it happens are left unsolved. In this project, we will take the broadband La3Si6N11:Ce-based yellow phosphors as the research objective, and phosphor films with designed optical and physical properties, will be fabricated. The effects of chemical composition, thermal quenching, decay time and thermal conductivity on the luminescence saturation behavior will be investigated. We are going to (i) clarify the mechanisms for luminescence saturation; (ii) propose a method for improving the saturation; and (iii) optimize the preparation conditions according to the feedback results. In the end, we attempt to develop the next-generation La3Si6N11:Ce-based laser phosphors with high saturation threshold, and to provide theoretical and experimental guidance for material design and optimization for white laser light with high color rendition, brightness and reliability.

激光照明是实现超高亮度照明最有效的技术手段之一。作为其中的关键材料，激光荧光材料直接决定了激光光源的显色指数、光通量和可靠性等技术参数。前期研究表明：现有荧光材料在极高入射激光光通量密度激发时容易产生发光饱和，但影响发光饱和的关键因素及作用机理尚不清楚。为了阐明这些机理和探索高可靠性发光材料，本项目拟以具有宽带发射光谱的新型La3Si6N11:Ce基黄色荧光材料为研究对象，设计制备不同光学和物理性能的La3Si6N11:Ce基荧光薄膜，系统研究高功率密度激光激发下，荧光材料的化学组成、热猝灭温度、荧光寿命、热导率等因素对发光饱和的影响规律，揭示发光饱和的产生机制，提出改善发光饱和的方法，根据反馈结果优化制备条件，开发下一代高发光饱和阈值的La3Si6N11:Ce基激光荧光材料，为高显指、高亮度、高可靠性激光白光光源提供材料设计和优化的理论、实验指导。

激光照明是实现超高亮度照明最有效的技术手段之一。现有荧光材料在极高入射激光光通量密度激发时容易产生发光饱和，但影响发光饱和的关键因素及作用机理尚不清楚。本项目研究结果表明：激光荧光材料的发光饱和机理为热致饱和、光致饱和，其中，热致饱和与荧光材料的内量子效率、热猝灭、热导率等直接相关；光致饱和与荧光材料的荧光寿命相关，且荧光寿命越长，光致饱和越严重；在此基础上，项目以宽带发射光谱的新型La3Si6N11:Ce基黄色荧光材料为研究对象，设计制备不同光学和物理性能的La3Si6N11:Ce基荧光薄膜，为高显指、高亮度、高可靠性激光白光光源提供了材料设计和优化的理论、实验指导。