Effect of p-NiO interlayer on efficiency of p-GaN/n-ZnO LED devices

Abstract

We report on numerical study of the characteristics of p-GaN/n-ZnO light-emitting diodes with p-NiO interlayer, and on LED design optimization which includes bandgap engineering, thickness and doping of constituent layers. The current-voltage dependences of investigated LEDs show a threshold voltage of 3.1 V and 5.4 V for the LED devices without- and with presence of p-NiO interlayer, respectively. It is found that p-NiO layer act as electron blocking layer, that lead to the enhance of charge carriers confinement in active region, and to the increasing of internal quantum efficiency (IQE) of LED devices in four times up to 0.5%.