Performance enhancement of blue InGaN Light-Emitting Diodes with P-GaN/InGaN SPS last barrier and P-AlGaN/GaN SPS EBL

The numerical simulations of blue InGaN/GaN light-emitting diodes (LEDs) with the combined structures of p-GaN/InGaN shortperiod superlattice (SPS) last barrier (LB) and p-AlGaN/GaN SPS electron blocking layer (EBL) are investigated by the Advance Physical Model of Semiconductor Devices (APSYS) program. The simulation results show that the newly designed LEDs get better performances over the original structure of InGaN/GaN LEDs. This is attributed to the enhancement of the hole injection efficiency and the improvement of the polarization field effect between the InGaN well and the GaN barrier layer in the multiple quantum wells (MQWs). Therefore, the simulation results exhibit a significant increment in radiative recombination rate and about 2.6 times enhancement in the internal quantum efficiency (IQE) at an injection current of 150 mA. More important of all, it also shows that the newly designed structure can obviously reduce the ratio of efficiency droop of the LEDs from 62 to 14.5%.