Performance Enhancement of InGaN/GaN Green QW LEDs with Different Interlayers and Doping in the Barriers

The effect of introducing an InAlN or AlGaN IL (interlayer) in between the barrier and QW for the green emission has been studied. The tensile strain of AlGaN compensates the compressive strain of InGaN/GaN interface. The IL increases the barrier potential and reduces the carrier leakage from the QW. These increase the device efficiency. By changing the doping in the barrier, the optical output can be increased for green QW LEDs with and without interlayer. The best results are obtained for the AlGaN IL which increases the transition probability up to 2 times, as compared to the QW LEDs, without IL.