GaN-based asymmetric two-step light-emitting diodes (LEDs) with a low indium content (LIn) InGaN shallow step was proposed and fabricated. It was found the LIn-InGaN shallow step can significantly enhance phase separation and/or inhomogeneous indium distribution in the active In(0.27)Ga(0.73)N layer. By inserting an In(0.08)Ga(0.92)N shallow step, it was found that we can enhance LED output power by a factor of 2.27 with an injection current of 20 mA.
