InGaN micro-pixellated light-emitting diodes with nano-textured surfaces and modified emission profiles
InGaN micro-pixellated light-emitting diodes with nano-textured surfaces and modified emission profiles
复制标题
DOI：
10.1007/s00339-011-6349-5
复制
发表时间：
2011-03
期刊：
影响因子：
--
通讯作者：
Z. Gong;Y. Zhang;P. Kelm;I. Watson;E. Gu;M. Dawson
中科院分区：
文献类型：
--
作者：
Z. Gong;Y. Zhang;P. Kelm;I. Watson;E. Gu;M. Dawson
我们介绍了InGaN发光二极管(LED)的制造细节和性能特征，该LED由互连的微像素阵列组成，其中每个微像素通过纳米压痕进行纳米织构。我们采取了进一步的步骤，将像素包含在菱形几何中。研究发现，这种菱形纳米织构微米LED的功率输出比传统的方形广域参考LED提高了57%。由于引入了多指电极，降低了织构LED的串联电阻。此外，这些LED在没有封装的情况下可以承受高达500毫安的工作电流，这意味着改进了散热能力。最后，分析了表面纹理、微LED结构和几何形状对光提取的综合影响。结果表明，表面纹理、微像素化和菱形几何结构的功率分别提高了32%、16%和9%，表明表面纹理是提高光提取效率的最有效的贡献。与传统正方形LED的标准朗伯发射模式相比，角度相关的远场光束分布也发生了显著的变化。电致发光强度从顶面和侧壁都有明显的增加。
We present the fabrication details and performance characteristics of InGaN light-emitting diodes (LEDs) consisting of arrays of interconnected micro-pixels where each micro-pixel is nano-textured via nano-imprinting. We have taken the further step of embodying the pixels in a rhomboidal geometry. It is found that the power output of these nano-textured micro-LEDs with rhomboidal geometries is 57% higher than that of conventional square-shaped broad-area reference LEDs. The series resistance of the textured LEDs is reduced, owing to the multi-finger electrodes introduced. Furthermore, these LEDs can sustain higher operation current of up to 500 mA without encapsulation, suggesting improved thermal dissipation capability. Finally, the combined effects of surface texturing, micro-LED configuration, and geometric shaping on the light extraction are analyzed. It is found that the power enhancement by surface texturing, micro-pixellating and the rhomboidal geometry are 32%, 16%, and 9%, respectively, implying that surface texturing is the most effective contribution to increasing the light extraction efficiency in our design. The angular dependent far-field beam profile is also remarkably changed, compared with the standard Lambertian emission pattern of the conventional square-shaped LEDs. Substantial increase in the EL intensity is evident from both the top surface and the sidewall.