Optical, structural, and electrochromic properties of cobalt oxide films prepared via the sol-gel route

Cobalt oxide films were prepared by the sol-gel dip-coating method on glass and conducting (fluorine-doped tin oxide) glass substrates for electrochromic applications. XRD studies revealed that coated films comprising two to 10 layers were amorphous. FTIR spectra exhibited peaks attributable to Co-O vibrations. SEM images revealed the formation of nanopores in the surface of four-layered films. The electrochromic properties of the films were studied using cyclic voltammetry and in situ spectroelectrochemical techniques. The four-layered CoO film exhibited the highest anodic diffusion coefficient among all the films (3.50×10−13 cm2/s) and optical transmission variation of 26%.