Effects of Electrode Materials on Coloration of Viologen Electrochromic Devices

• Main Authors: Yu-ping Jou, 周郁萍
• Other Authors: Wei-li Yuan
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/60574802382916923141

碩士 === 逢甲大學 === 材料與製造工程所 === 95 === Materials used in electrochromic devices (ECDs) have received wide attention in recent years. Normally an ECD comprises two electrodes and one layer of electrochromic electrolyte which is liquid, solid, or in gel state. The electrochromic material is either inorganic or organic. The inorganic materials such as nickel oxide have good weather stability and long duration of coloration after the power is turned off. In contrast, the organic materials such as heptyl viologen (HV) have long working life and low driving voltage. However, they normally lose coloration when the power is off. In order to make organic materials-based ECDs retained coloration on switching off the power, we propose in this study an approach to the goal by using different electrodes instead of modifying the molecular structures of the electrochromes. A simple ECD was made into a sandwich structure with ITO as one electrode and various polished metal plates as the other. HV dissolved in propylene carbonate (PC) and mixed with ferrocene served as the redox material. The ECD was analyzed by the cyclic voltammogram (CV) for detecting any possible chemical reactions between the electrode and the electrolyte. Results showed that Cu, Al, and S420 (stainless steel) plates retained their coloration after the power was turned off. Meanwhile, Ni and S304 lost their coloration after the power was off. Further experiments will be conducted to find a way to discolor the Cu, Al, and S420 plates in a reversible way.