Electrochromic NiO _x Film by DC Sputtering

(Received 11 October 1994, revised 3 April 1995, accepted 28 June 1995)

Abstract
DC sputtering technique was applied to prepare NiO _x film, in which nickel hydroxide was used directly as the target. XRD and SEM examination show that the film is uniform and full of small granules of almost the same size. Slight difference exists between the as-deposited film and the colored film. Some weak crystal peaks appear in the latter film. The film has good electrochromic property. The content of oxygen in the vacuum chamber has no obvious effect on the electrochromic property of the film. XPS was used to investigate the nickel atomic state in the film. The result shows that Ni ²⁺ is oxided into Ni ³⁺ with coloring. The transmittance of the film can vary from 5% to 74% in the visible range.