Highly efficient InGaN-based LED with pre-roughening backside of GaN substrate

This work proposes that roughening on the backside of a GaN substrate prior to InGaN-based LED growth not only simplifies fabrication steps for the LED but also cleans the other side of the substrate that was served as the surface growth for the LED. As compared to post-roughening, forward voltage of the LED has reduced at 3.48 V through the pre-roughening. Further, the peak external quantum efficiency of the LED on the pre-roughened substrate is 21.6% at 12 m A / c m 2 , while the LED on the post-roughened GaN substrate is 20.6% at 14 m A / c m 2 .