GaN基发光二极管芯片光提取效率的研究  

Study on Light Extraction Efficiency of GaN-based Light-emitting Diode Chips

作　　者：申屠伟进[1] 胡飞[2] 韩彦军[1] 薛松[1] 罗毅[1] 钱可元[2] 

机构地区：[1]清华大学电子工程系 [2]清华大学深圳研究生院半导体照明实验室,广东深圳518057

出　　处：《光电子．激光》2005年第4期385-389,共5页Journal of Optoelectronics·Laser

基　　金：国家重点基础研究发展规划资助项目(TG2000036601);国家高技术研究发展计划资助项目(2001AA312190;2002AA31119Z);国家自然科学基金资助项目(60244001)

摘　　要：基于蒙特卡罗方法模拟分析了限制GaN基发光二极管(LEDs)芯片光提取效率的主要因素。结果表明,GaN与蓝宝石之间的较大折射率差别严重限制了芯片光提取效率的提高,通过蓝宝石背面出光比通过p型GaN层的正面出光的芯片光提取效率至少高20%;同时,低GaN光吸收系数、高电极反射率以及环氧树脂封装可以有效的增加芯片光提取效率,并且LEDs芯片尺寸在400μm以下时光提取效率较高。The factors that limit light extraction efficiency of GaN-based light-emitting diodes (LEDs) chips were investigated by using Monte Carlo method. It is shown that the large refractive index difference between GaN and Al2O3 seriously limits the improvement of light extraction efficiency. The extraction efficiency is enhanced at least 20% by using the structure of flip-chip bonding than that of the top-emitting. The simulation results also indicate that light extraction efficiency will increase by reducing the optical absorption in GaN, improving reflectivity of electrode and packaging the devices by epoxy. Furthermore it is shown that the optimal chip size is below 400 μm. The analysis results will play a key role in the design and fabrication of high external quantum efficiency GaN-based LEDs.

关 键 词：提取效率 发光二极管 GaN 蒙特卡罗方法 光吸收系数 模拟分析 环氧树脂 芯片尺寸 LEDS 蓝宝石 折射率 反射率 限制 P型 封装 

分 类 号：TN312.8[电子电信—物理电子学] X833[环境科学与工程—环境工程]