The preparation of copper(II) oxide thin films and the study of their microstructures and optical properties

Copper(II) oxide thin films were prepared by a sol–gel-like method on microscope glass substrates. Precursor solutions were prepared by dissolving copper acetate in isopropyl alcohol. Various stabilizers and additives were used to enhance the solubility of copper acetate and to strengthen the adhesion between the films and the glass substrates. It was observed that the films crystallized to CuO with tenorite structure after heat treatment at 600 °C for 30 min. The general appearances of the films were uniform and brownish black in color. The microstructures of the films were substantially affected by the chemistry of the precursor solutions. The optical band gaps of the films were between 1.6 and 1.75 eV.