Comparison of the some electrochromic properties of copper (Ι) oxide thin films prepared by three different methods

Thin copper (Ι) oxide films were deposited onto FTO pre-coated glass substrates by three different methods: chemical bath deposition (electroless method), electrochemical deposition, and low vacuum evaporation. These films exhibited cathode electrochromism: coloration at a negative potential when the films were used as a working electrode of an electrochromic test device. Visible transmittance spectra of the Cu2O films were studied for the: as-is films, samples in bleached and in colored state in a wavelength region of 330-830 nm. Cyclic voltammograms showed reversible characteristic of the coloring/bleaching electrochromic process. The average coloration efficiency at 670 nm was calculated from graphical presentation of optical density versus inserted charge density. Results for the electrochromic properties of the films prepared by the three methods were compared and discussed. (Author)