The influence of the deposition conditions on the structural features and electrochromic properties of nickel oxide (NiO) films prepared by chemical vapor deposition has been investigated. NiO films have been prepared on fluorine doped tin oxide (FTO) coated glass substrates from nickel-acetylacetonate
precursor and their electrochromic properties have been studied by cyclic voltammetry in a 0.1 M KOH solution at room temperature. Films exhibiting only the NiO phase were obtained at deposition temperatures higher than 450 °C in a wide range of reactor pressures (0.13 to 66.6 kPa). Particularly,
NiO films prepared at 500–550 °C from 0.13 to 53.3 kPa are transparent in nature and exhibit a crystallite size varying from 10 to 60 nm. An appreciable anodic electrochromic change from transparent to black coloured resulted from a very porous surface morphology and film thickness
of about 3.5 μm. The electrochromic change was maintained over 3000 switching cycles. Nanostructured 3.5 μm-thick NiO films showed a maximum difference in optical transmittance of about 40% in the near-infrared region. These results make the nanostructured NiO films comparables
with those prepared by other deposition techniques.
Preparation of Vanadium-Titanium Oxide Thin Films by Sol-Gel Method and Their Electrochromic Properties