Structure optimization of deep ultraviolet laser diodes with superlattice electron blocking layer

In order to improve the optical and electrical performance of AlGaN-based deep ultraviolet laser diodes (DUV-LDs) and effectively reduce electron leakage in the active region, a superlattice electron blocking layer (EBL) structure is proposed. Based on the reference structure A, this paper designs a superlattice structure B with an upward gradient of Al composition and a superlattice structure C with a downward gradient of Al composition. By using Lastip software to simulate the above three types of structures and comparing their energy band diagram, p-zone electron concentration, P-I and V-I characteristics, it is concluded that the superlattice EBL structure C has the strongest electron blocking ability under the downward gradient Al composition, leading to the optimized device performance such as lower threshold current and higher slope efficiency.