Influence of a p-InGaN/GaN short-period superlattice on the performance of GaN-based light-emitting diodes

We have investigated the performance of GaN-based blue light-emitting diodes (LEDs) with a p-InGaN/GaN short-period superlattice (SPS) contact layer, which were grown by metal organic chemical vapor deposition. It was found that dot-like features appeared on the surface when a p-InGaN/GaN SPS structure was grown. The LED operating voltage decreased from 3.52 V to 3.15 V and the electrostatic discharge properties of LEDs were improved by using such a SPS structure. The output powers of LEDs were also increased by adjusting the In mole fraction in the SPS. However, the lifetime of LEDs became shorter when such a SPS structure was used.