Enhanced Light Output of GaN-Based Light-Emitting Diodes by Using Omnidirectional Sidewall Reflectors

We report on the enhancement of light output in GaN-based light-emitting diodes (LEDs) by using omnidirectional sidewall reflectors. Optical ray-tracing simulation results show that the light extraction efficiency of LEDs can vary in the range of 15.0%-24.4%, depending on the mesa depth, reflectivity, and profile angle of mesa sidewalls. Based on these findings, LEDs are fabricated with SiO
₂
-Al omnidirectional sidewall reflectors (at a mesa depth of 1.6 m and a sidewall profile-angle of 42deg). The LEDs show an enhancement of the light output by 18%, as compared with reference LEDs.