发光二极管的发光效率研究

JIMI

论文编号:WLX048  字数:7741,页数:18 摘      要 本论文对白光LED的发光效率进行了研究，从热效率的角度考虑，对在恒定电流下不同温度时的发光效率进行了实验分析，得出温度的升高增加了LED的热效率。并从理论上对此进行了分析，得出温度升高导致内量子效率和外量子效率的减小，从而减小了发光效率。LED在过高的温度下工作会使器件的性能下降，并使光强明显减小，同时温度过高还会使LED的封装材料产生不可恢复的应力性形变甚至有可能使LED内部接线断路，因此良好的散热装置可以使LED工作性能稳定并增加其使用寿命。关键词：白光LED  发光效率  热阻  温度AbstractThis paper makes a study and experimental analysis on luminous efficiency of white LED in terms of thermal efficiency, and arrives at a conclusion that an increase in temperature corresponds to an increase in thermal efficiency of LED. The paper also illustrates this phenomenon with a careful theoretical analysis and makes it clear that the reason of this phenomenon is that internal quantum efficiency and external quantum efficiency decrease when operation temperature increases. LED will not work well in an excessive high operation temperature and a visible light decay comes. A stress deformation which is beyond retrieve will appear on the encapsulating material of LED and it may make internal circuit of LED a break when operation temperature is excessive high, so good heat dissipation system will make the LED at a stable performance and a long operating life.Keywords：White LED ; Luminous efficiency; Thermoresistance; Temperature    目  录中文摘要..........................................................................i英文摘要.........................................................................ii目录............................................................................iii第一章   绪论.....................................................................1 1.1  LED简介................................................................1 1.2  LED器件结构及发光机理..................................................1 1.21 LED器件结构........................................................1          1.22 LED发光原理........................................................2 1.3  LED器件的发光效率......................................................2      1.31 内量子效率..........................................................2      1.32 外量子效率..........................................................3第二章   发光效率测试与分析.......................................................4 2.1  发光效率的测量原理..................................4 2.2  正向压降和结温的关系测量..............................4 2.3  热阻测量...............................................6       2.4  发光效率测量........................................8      2.5  实验结果分析...........................................................8第三章   发光效率理论分析........................................................10      3.1  温度影响发光效率的原因分析.............................................10      3.2  散热方法..............................................................11第四章   总结....................................................................13致谢.............................................................................14参考文献.........................................................................15