Crystal structure and gas sensing properties of Cu-doped zinc oxide

Abstract

Copper doped zinc oxide thin films are prepared by RF magnetron sputtering. The films are characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and other techniques. It is found that the films are composed of nano-crystal grains with typical columnar structure. The structural properties, such as preferred orientation, residual strains exist in the films, and grains size were studied. Moreover, the porous structure that related with the surface morphology of the films was discussed as it has relationship with the gas sensing property. Gas sensing property of these films was studied with the understanding of structural properties. The films were tested with NO gas. The sensitivity of the films was studied through the discussions of films structures.