The fabrication and field emission properties of ZnO nanoparticles-doped diamond-like carbon films by electrochemical deposition

Abstract

The formation of ZnO nanoparticles embedded in diamond-like carbon (DLC) thin film, deposited by electrochemical technique without post-processing, is observed. The effect of ZnO doping on the field emission (FE) property of DLC film is investigated. The chemical composition, the microstructure, and the surface morphologies of the sample are characterized by X-ray photoelectron microscopy, transmission electron microscopy, Raman spectrum, and atomic force microscope (AFM). It is shown that the ZnO nanoparticles are of a wurtzite structure and the content of ZnO increases with Zn source increasing in electrolyte. The ZnO doping enhances both the graphitization and the surface roughness of the DLC film, which is verified by Raman spectrum and AFM. By the ZnO doping, the FE properties of the DLC film are improved. An emission current density of 1 mA/cm2 is obtained at an electric field of 20.7 V/m for the film with a Zn/(Zn+C) ratio of 10.3at%. The improvement on the FE properties of the ZnO-doped DLC film is analyzed in the context of microstructure and chemical composition.