Investigation of AlGaN-based deep-ultraviolet light-emitting diodes with composition-varying AlGaN multilayer barriers

In this study, the characteristics of deep-ultraviolet light-emitting diodes (DUV-LEDs) with composition-varying AlGaN multilayer barriers are investigated numerically. The simulation results demonstrate that the proposed DUV-LEDs have better device performances, i.e., higher light output power and internal quantum efficiency, over their counterparts with typical single-layer AlGaN barriers. These improvements are attributed to the reduced markedly polarization-induced electrostatic field within the quantum wells (QWs), which is beneficial to enhance the electron-hole spatial overlap in QWs, suppress the electron leakage and increase the hole injection efficiency. Furthermore, the efficiency droop is also reduced significantly when the composition-varying AlGaN multilayer barriers are adopted.