Enhanced ultraviolet electroluminescence performance from p-NiO/n-GaN heterojunctions by using i-Ga2O3 as electron blocking layer

Abstract

In recent years, GaN materials have been applied to the field of optoelectronic devices due to their excellent photoelectric properties, especially in the field of light-emitting diodes, which has attracted considerable attention. In this article, we use structural engineering methods to further improve the performance of GaN-based ultraviolet light-emitting diodes. The magnetron sputtering and annealing treatment were used to prepare ultraviolet light-emitting diodes based on p-NiO/i-Ga2O3/n-GaN and p-NiO/n-GaN heterojunction structure. X-ray diffractometer, field emission scanning electron microscope and ultraviolet-visible spectrophotometer were used to study the crystal quality, surface morphology, and optical properties of Ga2O3 film. Compared with the p-NiO/n-GaN heterojunction diode, the p-NiO/i-Ga2O3/n-GaN heterojunction diode exhibits better rectification characteristics and more excellent electroluminescence characteristics. Under the injection voltage of 35 V, the EL spectrum intensity of p-NiO/i-Ga2O3/n-GaN heterojunction diode is nearly 37 times higher than that of p-NiO/n-GaN heterojunction diode. Finally, the working mechanism of the electroluminescence is analyzed in detail through the energy band diagram of the two diodes.