Carrier Transport Improvement in Blue InGaN Light-Emitting Diodes Via Reduced Polarization Using a Band-Engineered Electron Blocking Layer

Abstract

This study numerically investigates the effect of using a new electron blocking layer (EBL) for blue InGaN light-emitting diodes (LEDs) to improve hole injection efficiency and electron confinement. Simulation results suggest that the carrier transportation behavior of the EBL can be appropriately modified by adept control of the graded AlGaN layer. Furthermore, when compared with the conventional LED structure, the redesigned LED with graded AlGaN layer shows a slight improvement in forward voltage Vf and a significant enhancement in light output power. The redesigned LED can achieve an exceptional increment of 106.6% in light output power at 100 mA when compared with conventional LED. The observed improvement in the photoelectric performance of blue LEDs is primarily due to the reduced polarization effect at the last-barrier/EBL interface, as a result of the graded Al composition in EBL.