Huang Yu-Chieh, Lin Chia-Feng, Chen Sy-Hann, Dai Jing-Jie, Wang Guei-Miao, Huang Kun-Pin, Chen Kuei-Ting, Hsu Yi-Hsiang
Department of Materials Science and Engineering, National Chung Hsing University,Taichung 402, Taiwan.
Opt Express. 2011 Jan 3;19 Suppl 1:A57-63. doi: 10.1364/OE.19.000A57.
The conical air-void structure of an InGaN light-emitting diode (LEDs) was formed at the GaN/sapphire interface to increase the light extraction efficiency. The fabrication process of the conical air-void structure consisted of a dry process and a crystallographic wet etching process on an undoped GaN layer, followed by a re-growth process for the InGaN LED structure. A higher light output power (1.54 times) and a small divergent angle (120°) were observed, at a 20 mA operation current, on the treated LED structure when compared to a standard LED without the conical air-void structure. In this electroluminescence spectrum, the emission intensity and the peak wavelength varied periodically by corresponding to the conical air-void patterns that were measured through a 100 nm-optical-aperture fiber probe. The conical air-void structure reduced the compressed strain at the GaN/sapphire interface by inducing the wavelength blueshift phenomenon and the higher internal quantum efficiency of the photoluminescence spectra for the treated LED structure.
在氮化镓/蓝宝石界面形成了氮化铟镓发光二极管（LED）的锥形气孔结构，以提高光提取效率。锥形气孔结构的制造工艺包括在未掺杂的氮化镓层上进行干法工艺和晶体学湿法蚀刻工艺，随后是氮化铟镓LED结构的再生长工艺。与没有锥形气孔结构的标准LED相比，在20 mA的工作电流下，处理后的LED结构观察到更高的光输出功率（1.54倍）和较小的发散角（120°）。在该电致发光光谱中，发射强度和峰值波长通过对应于通过100 nm光孔径光纤探头测量的锥形气孔图案而周期性变化。锥形气孔结构通过诱导波长蓝移现象和处理后的LED结构光致发光光谱的更高内部量子效率，降低了氮化镓/蓝宝石界面处的压缩应变。
