Electrochromic behavior of NiO film prepared by e-beam evaporation

The NiO thin films were prepared by the electron beam evaporation method using synthesized sintered targets. As-prepared films were characterized using X-ray diffraction, scanning electron microscopy, UV-VIS spectroscopy and cyclic voltammetry. The thicker films were found to exhibit a well-defined structure and a well-developed crystallite size with greater transmittance modulation and durability. The as-deposited thinner films of 170 nm showed a faster response time during electrochromic cycles with a coloration efficiency of 53.1 C/cm2 than the thicker ones. However, the thicker films showed no enhanced electrochromic properties such as a larger intercalated charge than the thinner ones. The electrochromic properties of the thinner films became deteriorated after 800 cycling tests.