Acta Chimica Sinica ›› 2013, Vol. 71 ›› Issue (07): 1041-1046.DOI: 10.6023/A13020168 Previous Articles     Next Articles

Article

获得高性能电致变色薄膜的ITO表面修饰方法

杨树威a, 郑建明a, 吴星明a, 徐春叶a,b   

  1. a 中国科学技术大学合肥微尺度物质科学国家实验室 合肥 230026;
    b 中国科学技术大学化学与材料科学学院高分子科学与工程系 合肥 230026
  • 投稿日期:2013-02-02 发布日期:2013-05-02
  • 通讯作者: 郑建明, E-mail: jmz@ustc.edu.cn; Tel.: 0551-63603459, 0551-63603470;徐春叶, chunye@ustc.edu.cn E-mail:jmz@ustc.edu.cn;chunye@ustc.edu.cn
  • 基金资助:

    项目受国家自然科学基金(Nos. 21274138, 21074125);安徽省自然科学基金(No. 11040606M57);国家重点基础研究发展计划(No. 2010CB934700);中国科学院百人计划和中组部国家千人计划资助.

Modification of ITO Surface for High Performance of Electrochromic Polymer Film

Yang Shuweia, Zheng Jianminga, Wu Xingminga, Xu Chunyea,b   

  1. a Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026;
    b Department of Polymer Science and Engineering, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026
  • Received:2013-02-02 Published:2013-05-02
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21274138, 21074125), the Anhui Provincial Natural Science Foundation (No. 11040606M57), the National Basic Research Program of China (No. 2010CB934700), Hundred Talents Program of Chinese Academy of Sciences, the Thousand Talents Program of Chinese Central Government.

The relatively low reactivity of indium tin oxide (ITO) thin film coated on glass with its good conductivity and transparency make it the widely used electrode in displays and electrochromic devices. However, the inactivity of the surface may cause serious problems for physically deposited electrochromic polymer films from detachment to short durability, especially, in the presence of electrolyte liquids. We here report that significant improvement is made for electrochromic films of poly[3,4-(2,2-dimethylpropylenedioxy)thiophene] by electrodepositing its monomer on ITO surface modified with organic acids. We first designed and synthesized 2-thienyl phosphonic acid which was used to modify ITO glass. ITO glass was immersed in modifier solution vertically on a glass bracket and the solution was allowed to evaporate slowly at ambient condition. The glass was removed from the glass bracket when it was fully exposed to the air, and then baked at 120 ℃ for 24 h in glove box. After modification, the modifier molecules are able to react with hydroxyl groups on ITO surface by losing H2O and self-assemble to high-order monolayer. X-ray photoelectron spectroscopy results indicate that chemical binding is formed between the surface and the modifier. By attaching the modifier molecules to ITO surface with ester bonds, the surface changes from hydrophilic to hydrophobic, but the transmittance and conductivity remain the same as bare ITO. Atomic force microscope results demonstrate that surface roughness of modified ITO showed a little reduction compared with bare one. To test the mechanical strength of electrochromic polymer thin film on different substrate, we treated the films by sonication. The results reveal a much better stability for the film formed on the modified ITO than that on bare one. Meanwhile, color changing property of electrochromic polymer film electropolymerized on modified substrate remains the same as that on bare substrate. This study provides a conventional way to achieve high-performance polymer-based electrochromic films.

Key words: ITO surface modification, surface hydrophilicity, electrochromic film, adsorptivity