GaN-Based LEDs With Rough Surface and Selective KOH Etching

The authors propose a simple method to enhance the performances of GaN-based light-emitting diodes (LEDs) with rough surface. By using KOH to selectively smooth the area beneath the p-contact pad, it was found that we could reduce the forward voltage and enhance output power of the GaN-based LEDs. It was also found that wall-plug efficiency (WPE) of the proposed LEDs was 10.3% larger than that of the conventional LEDs with rough surface and 33.9% larger than that of the conventional LEDs with flat surface. Furthermore, it was found that the use of selective KOH etching will not degrade drooping effect of the LEDs.