Full‐Color Electroluminescence from ZnO Nanoparticles‐Based Homojunction Diodes

Abstract

Wide‐bandgap zinc oxide (ZnO)‐based light‐emitting diodes (LEDs) have attracted considerable interest for application in solid‐state lighting; however, the absence of dependable high‐quality homojunction has impeded their progress. A p–n homojunction LED is fabricated in this study using arc discharge‐fabricated N‐doped ZnO nanoparticles (NPs) spin coated over a Ga‐doped ZnO thin film. The homojunction LEDs demonstrate pure ultraviolet (UV) emissions with a narrow linewidth even at elevated temperatures. The UV intensity initially increases as the injection current increases to the saturation limit with a change in the peak position, followed by a decrease at higher injection currents. A proportion of UV light is downconverted into visible light using phosphors. Furthermore, the mixing of phosphors and their application to UV‐LED results in white emission with high color rendering and superior optical stability. Notably, the visible spectral peaks do not discernibly change with variations in the operating current. These findings represent significant advancements in the development of stable p‐type ZnO nanostructures, leading to the development of cost‐effective photonic devices.