基于白光LED应用的氮化物荧光粉的热致光衰机理研究

项目名称： 基于白光LED应用的氮化物荧光粉的热致光衰机理研究

项目编号： No.51272259

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 解荣军

作者单位： 厦门大学

项目金额： 80万元

中文摘要： 氮化物荧光粉被公认为是制造高显色、广色域、色温可调以及高光效白光LED最合适的波长变换材料之一，倍受学术界和产业界的青睐和关注。前期研究表明：发光性能优异的Sr2Si5N8:Eu红粉和SrSi2O2N2:Eu绿粉存在着严重的可导致白光LED迅速老化失效的热致光衰问题，但热致光衰的机理和解决方法尚不清楚。本项目以白光LED用氮化物荧光粉为研究对象，研究温度对荧光粉的发光性能(光谱、强度、量子效率、吸收率、发光寿命)的影响，考察一定温度条件下湿度和辐照强度的协同作用效应，掌握荧光粉热致光衰的变化规律；综合利用表面和微观结构等分析技术研究荧光粉的表面结构、化学组成、发光中心离子价态/浓度、局域结构的变化，揭示热致光衰的形成机制；初步建立正确评价热致光衰的方法；通过材料组成设计、荧光粉颗粒表面修饰、以及合成工艺优化达到实现高效、低光衰氮化物荧光粉的可控制备。

中文关键词： 白光LED；氮化物；发光材料；热致光衰；荧光光谱

英文摘要： Nitride phosphors are attracting considerable attention from both academic and industrial communities, which are well known as one of most suitable wavelength-conversion luminescent materials for fabricating white LEDs with high color rendition, wide color gamut, tunable color temperature and high efficiency. Our previous studies indicated that, thermal degradation occurred seriously in Sr2Si5N8 and SrSi2O2N2-based phosphors which showed excellent photoluminescent properties, leading to the fast degradation of white LEDs. Unfortunately, the thermal degradation mechanism and hence the solutions are not clear yet. In this project, we will clarify the thermal degradation mechanism of Sr2Si5N8 and SrSi2O2N2 phosphors by investigating the temperature effect as well as the synergistic effect of moisture and irradiation stresses on photoluminescent properties (i.e., spectrum, quantum efficiency, absorption, lifetime, etc.), and understanding the changes in surface, chemical composition, valence and concentration of activators, and local structure through surface and structure analyses. Also, we will attempt to establish the methods for evaluating thermal degradation of phosphors in white LEDs. Finally, we will try to realize the control synthesis of high efficiency and low degradation of nitride phosphors through compo

英文关键词： white LED；nitride；luminescent materials；thermal degradation；photoluminescence spectra