Enhancing the light extraction of GaN-based LEDs
GaN-based light-emitting diode (LED) has been widely used in recent years, and tremendous progress has been achieved in GaN-based semiconductor materials and relevant process. However, owing to the large refractive index contrast between GaN-based semiconductor materials and air, light can be easily totally internally reflected at the semiconductor/air interface, and the critical angle for light to escape from the semiconductor is small. Therefore, the light extraction efficiency for GaN-based LED is still low and needs improving. Some of the leading approaches to enhance light extraction efficiency of GaN-based LED such as surface texturing or roughening, omnidirectional reflectors, photonic crystals, laser liftoff, transparent electrode, patterned substrate and so on are introduced in detail. For each approach, how the variation in device structure or material improves the light extraction efficiency is analyzed thoroughly. At last, some of mentioned approaches that are promising are evaluated and viewed briefly.
light-emitting diode GaN light extraction efficiency surface texturing omnidirectional reflector photonic crystal laser liftoff transparent electrode patterned substrate
李艳玲 牛萍娟 李晓云
天津工业大学信息与通信工程学院,天津,300160
国际会议
成都
英文
2007-11-19（万方平台首次上网日期，不代表论文的发表时间）