Conical air prism arrays as an embedded reflector for high efficient InGaN/GaN light emitting diodes

摘要

The effect of the combination of triangular prisms and cones as air-void structures arrays on the enhancement of light extraction efficiency of InGaN light-emitting diodes (LEDs) is investigated. The arrays embedded at the sapphire/GaN interface act as light reflectors and refractors, and thereby improve the light output power due to the redirection of light into escape cones on both the front and back sides of the LED. Enhancement in radiometric power as high as 74% and far-field angle as low as 125° is realized with a compact arrangement of arrays compared with that of a conventional LED.