Performance Enhancement of Blue InGaN Light-Emitting Diodes With a GaN–AlGaN–GaN Last Barrier and Without an AlGaN Electron Blocking Layer

Blue InGaN light-emitting diodes with a GaN-AlGaN-GaN last barrier (GAGLB) and without an AlGaN electron blocking layer (EBL) are investigated numerically. When the conventional last GaN barrier is replaced by a GAGLB and the most commonly used AlGaN EBL is removed, the forward voltage is reduced from 3.39 to 2.98 V, and the efficiency droop is improved from 30.1% to 14.2%. Simulation results indicate that these improvements can be attributed to the effective barrier height increase for electron confinement and to hole injection efficiency enhancement due to tunneling effect in the GAGLB.