Sputtered Electrochromic V2O5 Films

Vanadium oxide films were deposited by reactive dc magnetron sputtering from a vanadium target in argon-oxygen gas mixtures. The composition and structure of these films were investigated by X-ray photoelectron spectroscopy and X-ray diffraction. Films with the approximate composition V₂O₅ were amorphous when deposited at room temperature and had a reversible color change when lithium was electrochemically injected. Because the color change is slight, these films could be used as a counterelectrode to a more strongly coloring material.