Characterization of copper oxide thin films deposited by the thermal evaporation of cuprous oxide (Cu2O)

Thin films of copper oxide were deposited by thermal evaporation of cuprous oxide (Cu2O) powder. The substrates were either unheated or heated to a temperature of 300 °C. The films were also annealed in air at a temperature of 500 °C for 3 h. The films were characterized by X-ray photoelectron spectroscopy, X-ray diffraction and UV-visible spectrophotometry. The effects of the substrate temperature and post-deposition annealing on the chemical, structural and optical properties of the films were investigated. As-deposited films on unheated substrates consisted of mixed cupric oxide (CuO) and Cu2O phases, with a higher concentration of the Cu2O phase. However, the films deposited on heated substrates and the annealed films were predominantly of the CuO phase.