Influence of n-type versus p-type AlGaN electron-blocking layer on InGaN/GaN multiple quantum wells light-emitting diodes

The effect of n-AlGaN versus p-AlGaN electron-blocking layers (EBLs) on the performance of InGaN/GaN light-emitting diodes is studied in this work. Experimental results suggest that the n-type EBL leads to higher optical output power and external quantum efficiency, compared to the devices with p-AlGaN EBL, which is commonly used today. Numerical simulations on the carrier distribution and energy band diagram reveal that the n-AlGaN EBL is more efficient in preventing electron overflow, while not blocking the hole injection into the active region, hence leading to higher radiative recombination rate within the multiple quantum wells active region. © 2013 AIP Publishing LLC