Electrochromic properties of NiOOH thin films prepared by reactive sputtering in an H _2O atmosphere in various _(aq)ueous electrolytes

摘要

Nickel oxyhydroxide (NiOOH) thin films were prepared by reactive sputtering using H _2O as a reactive gas, and the electrochromic (EC) properties of these thin films were investigated in alkaline, neutral, and acidic _(aq)ueous electrolyte solutions. A stable EC cycling of up to 100 cycles was obtained for the NiOOH thin films in electrolyte solutions with a wide pH range of 4.113.5. However, the EC cycling degraded drastically after several tens of cycles in an electrolyte with pH=2.0. In the stable pH region, the NiOOH films exhibited a large transmittance change from approximately 3090%, although the response speed slowed with decreasing pH of the electrolytes.