Effect of Asymmetric InAlGaN/GaN Superlattice Barrier Structure on the Optoelectronic Performance of GaN-Based Green Laser Diode

Abstract

An asymmetric InAlGaN/GaN superlattice barrier structure without the first quantum barrier layer (FQB) is designed, and its effect on the optoelectronic performance of GaN-based green laser diode (LD) has been investigated based on simulation experiment and analytical results. It is found that, compared with conventional GaN barrier LD, device performance is significantly improved by using FQB-free asymmetric InAlGaN/GaN superlattice barrier structure, including low threshold current, high output power, and high photoelectric conversion efficiency. The threshold current of LD with novel structure is 16.19 mA, which is 22.46% less than GaN barrier LD. Meanwhile, the output power is 110.69 mW at an injection current of 120 mA, which is 16.20% higher compared to conventional LD, and the wall-plug efficiency has an enhancement of 9.5%, reaching 20.27%. FQB-free asymmetric InAlGaN/GaN superlattice barrier layer can reduce optical loss, suppress the polarization effect, and improve the carrier injection efficiency, which is beneficial to improve output power and photoelectric conversion efficiency. The novel epitaxial structure provides theoretical guidance and data support for improving the optoelectronic performance of GaN-based green LD.