Stacked GaN/AlN last quantum barrier for high-efficiency InGaN-based green light-emitting diodes

Realization of efficient InGaN-based green light-emitting diodes (LEDs) is highly desirable in solid-state lighting industry. Here, we propose a stacked last quantum barrier (SLQB) GaN/AlN layer for green (similar to 550 nm) LEDs grown on patterned sapphire substrate to improve the device performance. A green LED with a SLQB achieves a light output power (LOP) of 13 mW at 15 mA, which is 35% higher than that of LEDs with a conventional last quantum barrier (CLQB) GaN layer. In addition, the forward voltage of the green LED with the SLQB is reduced by 0.16 V compared with green LEDs with theCLQB. Simulation results demonstrate that the AlN layer in the SLQB increases the effective barrier height for electrons and alleviates the electron leakage effect. It also enables an intraband tunneling process for holes to inject into the active region, promoting the hole injection efficiency. As a result, we successfully obtain InGaN-based green LEDs with remarkably improved carrier injection efficiency by adopting the SLQB structure. (C) 2021 Optical Society of America

Automated summary

A stacked last quantum barrier (SLQB) GaN/AlN layer was proposed to enhance the performance of green LEDs, resulting in higher light output power and lower forward voltage. Simulation results showed that the SLQB structure increased the effective barrier height for electrons, alleviated electron leakage, and promoted hole injection efficiency.