Improved carrier injection and confinement in InGaN light-emitting diodes containing GaN/AlGaN/GaN triangular barriers**Project supported by the National Key Research and Development Program of China (Grant Nos. 2017YFB0403100 and 2017YFB0403101), the National Natural Science Foundation of China (Grant Nos. 61404114, 61504119, and 11004170), the China Postdoctoral Science Foundation (Grant No. 2017M611923), and the Jiangsu Planned Projects for Postdoctoral Research Funds, China

Abstract

In this study, an InGaN lighting-emitting diode (LED) containing GaN/AlGaN/GaN triangular barriers is proposed and investigated numerically. The simulation results of output performance, carrier concentration, and radiative recombination rate indicate that the proposed LED has a higher output power and an internal quantum efficiency, and a lower efficiency droop than the LED containing conventional GaN or AlGaN barriers. These improvements mainly arise from the modified energy bands, which is evidenced by analyzing the LED energy band diagram and electrostatic field near the active region. The modified energy bands effectively improve carrier injection and confinement, which significantly reduces electron leakage and increases the rate of radiative recombination in the quantum wells.