Improved light extraction of GaN-based green light-emitting diodes with an antireflection layer of ZnO nanorod arrays

摘要

We investigate the effect of double ZnO nanorod layers on the light extraction of green light-emitting diodes (LEDs). The double ZnO nanorod layers with a step gradient of the refractive index are formed as antireflection layers on the transparent electrode of LEDs. The light output power of the green LEDs with ZnO nanorods is increased by 42.9% at an injection current of 20 mA compared to those without ZnO nanorods. The increase in light output power is mostly attributed to a reduction in Fresnel reflection by antireflection layers of ZnO nanorods on green LEDs.