Simulation and fabrication of N-polar GaN-based blue-green light-emitting diodes with p-type AlGaN electron blocking layer

N-polar GaN-based blue-green light-emitting diodes (LEDs) with p-AlGaN electron blocking layer (EBL) were numerically investigated by simulation and experimentally grown on vicinal C-face SiC substrates by metal–organic chemical vapor deposition. By numerical simulation, we can find that p-AlGaN EBL in N-polar LEDs is able to play a more important role in blocking electron overflow than that in Ga-polar LEDs due to the reversed polarization, which leads to a high output power and internal quantum efficiency. Besides, the holes injection efficiency is enhanced in N-polar LED, resulting in a lower turn-on voltage. In experimental studies, N-polar LEDs based on different numbers of quantum wells were grown on vicinal C-face n-SiC substrates. When a forward bias is applied to the epitaxial N-polar LED with two quantum wells, a strong blue-green emission located at 480 nm can be observed. This work indicates that N-polar group-III nitrides have great potential in the application of optoelectronic devices.