中文摘要：

分析了常规AlGaInP系发光二极管（LED）光提取效率低的主要原因，半导体的折射率与空气折射率相差很大，导致全反射使有源区产生的光子绝大部分不能通过出光面发射到体外。通过在LED出光层采用纳米压印技术引入表面纳米结构，以改变光子的传播路径，从而使得更多的光子能够发射到体外。理论分析与实验结果表明，与常规平面结构相比，纳米结构的引入，器件发光强度平均增加了1倍以上。

英文摘要：

The reason for low extraction efficiency of A1GalnP light emitting diodes （LEDs） has been analyzed, and there is a significant gap between the internal efficiency of LEDs and their external efficiency. The reason is the narrow escape cone for light in high refractive index semiconductors. The application of nano-imprint lithography to A1GaInP based LEDs~ surface texturing has been done, which is much easier for light to escape from the LED structure and thereby avoids absorption. In this paper, we have demonstrated nearly 100% improvement of luminous intensity in the nano-surface LEDs compared with LEDs with a flat surface. LEDs with nano-surface have higher extraction efficiency,lower heat generated and better optical characteristics than LEDs with a flat surface.