Structural and Electrochromic Properties of Co-Oxide and Co/Al/Si-Oxide Films Prepared by the Sol-Gel Dip Coating Technique

The sol-gel dip-coating technique was used for depositing cubic spinel Co₃O₄ and amorphous Co/Al/Si-oxide thin films. Both types of films exhibit similar electrochrochemical properties which are accompanied by the hydration of the structure. The electrochromic properties of Co/Al/Si-oxide surpass those already known for Co-oxide based electrochromic materials. The change in transmittance for spinel Co₃O₄ is 25%, while for Co/Al/Si-oxide films exceeds 50%. The electrochromic efficiency () for Co₃O₄ and Co/Al/Si-oxide films was 22 cm² C^-1, which is comparable to other electrochromic oxides. Good electrochromic properties of the Co/Al/Si-oxide films make them promising materials for active counter electrode in electrochromic devices.