Liquid Phase Deposition of Electrochromic Thin Films

Thin films of titanium, zirconium and nickel oxides were deposited on conductive SnO₂:F glass substrates by immersion in aqueous solutions. The films are transparent, conformal, of uniform thickness and appearance, and adhere strongly to the substrates. On electrochemical cycling, TiO₂, mixed TiO₂-ZrO₂, and NiOx films exhibited stable electrochromism with high coloration efficiencies. These nickel oxide films were particularly stable compared with films prepared by other non-vacuum techniques. The method is simple, inexpensive, energy efficient, and readily scalable to larger substrates.