Hole transport enhancement by thickness- and composition-grading of electron blocking layer

We have numerically examined the advantages of thickness- and composition-grading of the electron blocking layer (EBL) in InGaN multiquantum well light-emitting diodes. We have enhanced the hole confinement inside the active region, which is critical in GaN-based devices. Low hole injection is more severe when conventional wide bandgap AlGaN EBL is inserted between the last GaN quantum barrier and the p-GaN layer. The results obtained show reduced valence band offset leading to improved hole injection and enhanced device performance.