Nitride-Based Asymmetric Two-Step Light-Emitting Diode With In$_{0.08}$ Ga$_{0.92}$ N Shallow Step

A nitride-based asymmetric two-step light-emitting diode (LED) with $\hbox{In}_{0.08} \hbox{Ga}_{0.92}\hbox{N}$ shallow step was proposed and fabricated. It was found that the low indium content $\hbox{In}_{0.08} \hbox{Ga}_{0.92}\hbox{N}$ layer can significantly enhance phase separation and/or inhomogeneous indium distribution in the active $\hbox{In}_{0.27}\hbox{Ga}_{0.73}\hbox{N}$ layer. It was also found that we can enhance LED output power by a factor of 2.27 by simply inserting an $\hbox{In}_{0.08} \hbox{Ga}_{0.92}\hbox{N}$ shallow step.