Influence of the microstructure geometry of patterned sapphire substrates on the light extraction efficiency of GaN LEDs.
Influence of the microstructure geometry of patterned sapphire substrates on the light extraction efficiency of GaN LEDs.
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DOI：
10.1364/ao.55.007387
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发表时间：
2016-09
期刊：
影响因子：
1.9
通讯作者：
C. Kuo;Lung-Hsing Hsu;Bo-Hsin Huang;H. Kuo;C. Lin;Yuh-Jen Cheng
中科院分区：
文献类型：
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作者：
C. Kuo;Lung-Hsing Hsu;Bo-Hsin Huang;H. Kuo;C. Lin;Yuh-Jen Cheng
数值分析了图形化蓝宝石衬底（PSS）的微结构对GaN发光二极管（LED）光提取效率（LEE）的影响。研究了不同尺寸的锥结构，沿着与圆顶和混合微观结构。发现LEE主要取决于微结构表面斜率。LEE随斜率迅速上升，当斜率超过0.6时，LEE消失。缩小微观结构对LEE的影响不大。与生长在平坦衬底上的LED相比，发现光射线在PSS LED中行进更长的距离。保持GaN吸收损耗低对于LEE优化是重要的。
The influence of the microstructure geometry of patterned sapphire substrates (PSS) on the light extraction efficiency (LEE) of GaN light-emitting diodes (LEDs) is numerically analyzed. Cone structures of various dimensions are studied, along with dome and mixed microstructures. LEE is found to mainly depend on the microstructure surface slope. LEE rises quickly with slope and flattens out when the slope exceeds 0.6. Scaling down the microstructure has little effect on LEE. Light rays are found to travel longer distances in PSS LEDs, as compared with LEDs grown on a flat substrate. Keeping GaN absorption loss low is important for LEE optimization.