AlGaN-Based Deep Ultraviolet Laser Diodes with Graded AlInGaN Last Quantum Barrier

In this paper, we proposed two kinds of graded AlInGaN last quantum barrier (LQB) structures to improve the optical performance of deep ultraviolet laser diodes (DUV LDs). Through the analysis of the P-I curves, carrier concentrations and stimulated radiation recombination rates, we have got the results that the graded AlInGaN LQB structures have higher output power and lower threshold current compared to conventional structure. Besides, the carriers concentration and stimulated radiation recombination rates in the last quantum well are higher than those in the conventional structure, which indicateqa that graded AlInGaN LQB structure significantly improved the performance of DUV LDs.