Role of the electron blocking layer in the current transport of efficient III-N light-emitting diodes

Electron blocking layers (EBLs) are commonly used to reduce the leakage current in modern multi-quantum well (MQW) InGaN light-emitting diodes (LEDs). We study the effect of the EBL and doping on the operation and efficiency of LEDs. We simulate both conventional MQW LEDs with AlGaN EBL, LEDs with quaternary AlInGaN EBL and LEDs without EBL. We show that the elimination of the polarization charges at the EBL interface greatly enhances the injection efficiency and that the hole injection in MQW lattice can be optimized by doping. The efficiency droop limiting the high power operation is also analyzed to determine the underlying mechanisms in the simulated MQW structures. Based on these results, we discuss the measures to increase the overall efficiency MQW structures.