Enhancing the Carrier Injection Efficiency in AlGaN‐Based UV‐B Laser Diodes

AlGaN‐based ultraviolet (UV)‐B laser diodes (LDs) face considerable challenges in achieving high efficiency due to the low carrier injection efficiency at the interface between the electron‐blocking layer (EBL) and the AlGaN optical waveguide layer. Herein, the effects of the bandgap discontinuity (Δ E g ) between the EBL and the AlGaN optical waveguide layer and the steepness of the heterojunction interface on the carrier injection efficiency are investigated. Simulation results show that increasing Δ E g and the steepness of the heterojunction interface improve the carrier injection efficiency. Furthermore, the effects are verified in actual devices, demonstrating that the threshold current density of UV‐B LDs reduces and the carrier injection efficiency improves. These results provide important insights into the design of high‐efficiency AlGaN‐based UV‐B LDs and highlight the important role of crystal growth in achieving remarkable performance.