Synthesis, characterization and optical properties of NiO:Cs thin film

•Cs doped NiO thin films were prepared by the sol–gel dip-coating for first time.•Cs made disorder in NiO cubic structure.•This disorder was responsible for the enhancement of NiO columbic charge capacity.•High durability and reversibility weres achieved.

Transition metal oxides have shown an encouragement for industrial applications especially in lithium-ion batteries, electrochromic windows, and fuel cell films. The kinetic of addition of group I elements into transition metal oxides resulted in an improvement in their physical properties. Here, we reported the influence of doping of cesium on the electrochromic and crystalline structure of nickel oxide films. The results showed that a small amount of cesium (1 wt%) made a disorder of the NiO cubic structure. This disordered structure resulted in an improvement in the amount of Coulomb's charge by a factor of 2 as compared to NiO alone. A higher contrast ratio accounting for improved electrochromic performances was also observed for Cs doped NiO thin film as compared to NiO film. This novel structure is a promising candidate for industrial applications in renewable energy devices.