Investigation of structural properties of electron-beam deposition of zinc oxide coatings doped with copper

A new method of vacuum formation of doped ZnO coatings is proposed. ZnO thin films doped with copper were coated in silicon substrate by low-energy electron beam deposition method. The authors investigated the effect of deposition parameters on the structural properties of the ZnO thin films. The orientation of the ZnO thin films were investigated by X-ray diffraction (XRD) patterns. The doping of zinc oxide coatings with copper led to a disorienting effect. It has been shown that copper has a nonmonotonic effect on the bandgap value, which is changing from 2.67 to 3.33 eV. The increase in Eg is determined due to the changes in structure of ZnO matrix layer with low concentration of Cu, whereas with high concentration of copper, Eg decreases due to the presence of copper oxide as a separate phase. UV-Vis and IR spectra demonstrate the significant change in structure of ZnO in presence of Cu.