The Research On Preparation And Electrochromism Nickel Oxide Films

Electrochromic (EC) materials are new functional materials, which have wide use in these aspects of information, electron, energy sources, architecture, national defense and etc. Electrochromism can be defined as a persistent and reversible optical transformation induced by electrochemical processes. They can be classified as anode colored and cathode colored materials by electrochemical reaction modes. In this thesis, the researches on electrochromic materials were reviewed roundly, and the electrochromic mechanisms of nickel oxide films were systematically summarized. Besides these, the preparation methods and their properties and the structure of electrochromic device were described in detail. Furthermore, the ion conductivity mechanism and present research of solid electrolyte were also systematically summarized.The films were prepared by RF magnetron sputtering method, divided by different O/Ar ratio and the effect of annealing techniques of the electrochromic properties of these films was discussed. To find the parameters of preparation and annealing process associated with the best electrochromic properties of these films, following researches and experiments were carried out to find out the effect of the electrochromic property of nickel oxide films with different heat treatment.To compare the visible light transmittance of the electrochromic films which were annealed at different temperatures, we found that the higher temperature of heat treatment is, the higher transmittance of the nickel oxide film is, and we also found the temperature between 250℃and 350℃is proper to meet our need in good transmittance and good electro chromic property. X-ray diffraction(XRD) and X-ray photoelectron spectroscopy (XPS) had been used to define the property of the surface of the nickel oxide films, and scan electron spectroscopy(SEM) had also been used to figure out the difference of the surface morphology of the nickel oxide films with different O/Ar ratio and different heat treatment temperature. While discussing the different electrochromic properties of the films, the effect of annealing on the microstructure of films was found. It was clarified that why nickel oxide with different condition exhibited different electrochromic capabilities.