Alternating InGaN barriers with GaN barriers for enhancing optical performance in InGaN light-emitting diodes

Abstract

InGaN-based light-emitting diodes (LEDs) with some specific designs on the quantum barrier layers by alternating InGaN barriers with GaN barriers are proposed and studied numerically. In the proposed structure, simulation results show that the carriers are widely dispersed in the multi-quantum well active region, and the radiative recombination rate is efficiently improved and the electron leakage is suppressed accordingly, due to the appropriate band engineering. The internal quantum efficiency and light-output power are thus markedly enhanced and the efficiency droop is smaller, compared to the original structures with GaN barriers or InGaN barriers. Moreover, the gradually decrease of indium composition in the alternating quantum barriers can further promote the LED performance because of the more uniform carrier distribution, which provides us a simple but highly effective approach for high-performance LED applications.