Nickel Oxide Electrochromic Thin Films Prepared by Reactive DC Magnetron Sputtering

Abstract

Nickel oxide electrochromic thin films were prepared by reactive DC magnetron sputtering. The as-deposited optical property and electrochromic behavior strongly depended on the target operation mode and the substrate temperature. The sample sputtered with low oxygen flow rate, high power and substrate temperature of 200-300° C showed a wide transmittance modulation range, and the deposition rate was as high as 30 nm/min. Its integrated luminous transmittance could be controlled from 6.6 to 82.3%. X-ray diffraction measurements of this sample in a colored state and bleached state suggested that the boundary and surface of NiO microcrystallites played an important role in the electrochromic reaction of sputtered nickel oxide films.