Zn-doped NiO thin films were prepared using the simple sol-gel spin-coating method and
their electrochromic characteristics were compared with undoped NiO thin film. The
transparency in the visible region and uniformity of the NiO thin films were enhanced with
increasing Zn doping amounts. The in situ optical transmittance spectra revealed all
samples were transparent at bleached state, whereas the color changed from light brown to
dark brown at a colored state, as the Zn doping amounts increased. The Zn-doped NiO thin …