Enhancement of performance characteristics of violet InGaN DQW laser diodes using InGaN/GaN multilayer barriers

InGaN/GaN multilayer barriers (MLBs) have been theoretically and experimentally applied to improve InGaN-based light-emitting diodes (LEDs). In this study, the effects of InxGa1-xN/InyGa1-yN/InzGa1-zN MLBs on the performance of violet InGaN double quantum well (DQW) laser diodes (LDs) were numerically investigated for the first time. Simulation results indicated that InGaN/GaN MLBs effectively improved the output power, optical intensity, differential quantum efficiency, and slope efficiency of InGaN LDs compared with conventional LD structures. Moreover, the barriers effectively reduced the electric field and charge space in the active region, which are induced by built-in polarization. The threshold current was also reduced. Simulation results indicated that the proposed LD structures with InGaN/GaN MLBs presented lower electron leakage, enhanced carrier contribution in the radiative recombination, and consequently higher efficiency.