High Radiative Recombination Rate of AlGaN-Based Deep Ultraviolet Light-Emitting Diodes with AlInGaN/AlInN/AlInGaN Tunnel Electron Blocking Layer

In this study, an aluminum indium gallium nitride (AlInGaN)/aluminum indium nitride (AlInN)/aluminum indium gallium nitride (AlInGaN) tunnel electron blocking layer (EBL) is introduced instead of traditional EBL in aluminum gallium nitride (AlGaN)-based deep UV light-emitting diodes (DUV LEDs). The simulation results reveal that the internal quantum efficiency (IQE) and radiative recombination rate are impressively improved in the proposed DUV LED as compared to the conventional LED. This significant improvement is assigned to the uniform recombination of carriers in the active zone due to the reduction of lattice mismatching, which is the main cause of reducing the induced piezoelectric polarization field. Additionally, the tunnel EBL in our proposed structure also assists the hole transport into the active zone. As a result, not only is IQE improved, but also the efficiency droop is reduced significantly in our proposed device. This is attributed to the enhanced recombination of electron-hole pairs in the active region.