The reason for low extraction efficiency of AlGaInP 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 AlGaInP 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...