초록 |
Electrochemical preparation of ceramic thin films on substrates, which has several advantages over conventional methods, is a relatively new method. Zinc oxide has optical and electrical properties and its thin film has been prepared by CVD, sputtering and sol-gel processes. ZnO film has potential applications in energy efficiency windows, solar cells, liquid crystal displays, varistor and other optoelectronic devices. In our work, the mechanism of ZnO film formation on ITO glass was investigated with quartz crystal microbalance(QCM), which can detect mass change during film formation. In the beginning of film formation, the tetra-coordinate aquo zinc ions in solutions are adsorbed on the glass and then, zinc hydroxide is formed with the increase of pH due to the reduction of nitrate ions. QCM results supported that, during the film growth, zinc hydroxide is initially formed and transformed into ZnO. It also suggests that the pH on the substrate is very important in the film growth. The film growth rate is significantly enhanced by pH increase due to the reduction of oxygen and water.
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