藉由光輔助電化學表面粗化製程增加氮化銦鎵發光二極體光取出效率

Enhanced Light Extraction Efficiency in InGaN Light-Emitting Diodes through the Photoelectrochemical Surface Roughening Process

楊仲傑(Chung-Chieh Yang) ； 林春敏(Chun-Min Lin) ； 林佳鋒(Chia-Feng Lin)

《光學工程》 103期 (2008/10) Pp. 55-62

https://doi.org/10.30011/OE.200810.0006

摘要

在此文章中，我們利用表面粗化製程方式增加氮化銦鎵發光二極體光取出強度，此粗化的結構包含了圓錐狀的側壁、倒六角錐結構、奈米孔隙表面結構以及濕式平台蝕刻，而這些粗化的結構都是利用光輔助電化學製程方式製作出。由於氮化鎵材料與空氣的折射係數差異，光產生全反射的臨界角約等於23°，導致光能從表面取出了比例只有4%，藉由這些粗化的結構可以降低全反射的效應並且增加光的散射進而增加光取出效率。因此，光輔助電化學製程適合在高亮度氮化鎵發光二極體的應用。

關鍵字

圓錐狀結構 ； 倒六角結構 ； 奈米孔隙 ； 光輔助電化學

並列摘要

In this letter, we will report on an InGaN-based light emitting diode with a surface roughening process that increases light output power. The roughening structure included with cone-shaped sidewall, hexagonal inverted pyramids (HIP), nanoporous surface structure and wet mesa etching. These roughening structures were fabricated by the photoelectrochemical (PEC) process. With the refractive indexes for GaN (n=2.5) and for air (n=1), the angle of total internal reflection for the light escape cone is about 23°, and the light extraction ratio from the surface is about 4%. The roughening structures could reduce the total internal reflection effect and increase the light scattering to enhance light extraction efficiency. Consequently, this PEC treated process is suitable for high powered nitride-based LEDs lighting applications.

並列關鍵字

cone-shaped sidewall ； hexagonal inverted pyramids ； nanoporous ； photoelectrochemical PEC