Doped Effects of Quaternary AlInGaN Last Quantum Barrier for Deep-Ultraviolet Laser Diodes Without Electron Blocking Layer

In this work, we investigate the performance of doped quaternary AlInGaN last quantum barrier (LQB) of deep-ultraviolet laser diodes (DUV LDs) without the electron blocking layer (EBL). The results indicate that the stimulated radiation recombination rate of the n–p-doped LQB structure increases. Compared with the undoped LQB structure, the threshold current of the n–p-doped structure of quaternary AlInGaN LQB for DUV LDs without EBL decreases from 43.79 to 36.59 mA, the slope efficiency increases from 1.20 to 1.28 W/A, and the threshold voltage increases from 4.62 to 4.63 V. These results demonstrate that the n–p-doped structure can significantly improve the performance of DUV LDs.