本研究利用電化學方式來製備聚(3,4-乙烯二氧噻吩) (PEDOT)薄膜及其複合薄膜並探討其特性。實驗中使用3,4-乙烯二氧噻吩(EDOT) 作為單體，polystyrene sulfonate (PSS)作為添加劑，在定電位或循環電位下進行聚合，探討溶液中EDOT和PSS的比例(1:0、1:1.25及1:6)、不同陰離子(PSS或SS)、酸性溶劑(CH3COOH、HCl、H2SO4與HClO4)以及陽離子添加劑(C8-NH2、C12-NH2及C18-NH2)等變因對PEDOT薄膜特性的影響。首先對不同EDOT:PSS比例做探討，由循環伏安法與電化學阻抗分析得知，PEDOT:PSS薄膜對鈷電解液氧化還原對的催化活性會隨著水溶液中PSS濃度增加而下降，這是因為PSS高分子的催化活性較PEDOT差，為了降低PSS對PEDOT聚合薄膜的影響，因此在後續的研究中選用EDOT:PSS=1:1.25的系統來做不同聚合條件下的比較。第二部分的探討中我們以PSS的單體SS作為添加劑，發現SS可以保留PSS幫助聚合的能力，又可以降低PEDOT薄膜對催化活性與形貌的影響。在不同酸性溶劑的探討中發現，pH值越低EDOT聚合的能力越好，但硫酸的磺酸基易與PEDOT產生作用，導致界面阻抗值比使用過氯酸大，且以XPS的分析來看，薄膜的比例中PEDOT:SS最低，代表過氯酸既可以幫助EDOT聚合又可以將過多的SS去除，達到更佳催化活性與較低的界面阻抗值。最後探討胺基分子對EDOT聚合的效應，由於胺基分子易隨電位不同而進行吸附、脫附，又可以幫助EDOT在水中的分散，在使用循環電位聚合法時，胺基分子可以在EDOT聚合後的負電掃描時脫附，不滯留於薄膜中，而添加C12-NH2聚合出的PEDOT薄膜效果最佳。本研究最後將所製作的PEDOT及其複合薄膜作為染敏太陽能電池的對電極，所得的光電轉換效率依序為8.52% (PEDOT/ C12-NH2)，8.49% (PEDOT:SS)，7.97% (PEDOT:PSS)，及7.87% (PEDOT)。

In this study, poly(3,4-ethylenedioxythiophene) (PEDOT) films and their composite films were prepared by electrochemical methods. The monomer 3,4-ethylenedioxythiophene (EDOT) was dissolved in a solution with polystyrene sulfonate (PSS) as an additive, and the polymerization was controlled under constant or cyclic potential to investigate the ratio of EDOT and PSS in the solution (1: 0, 1:1.25 and 1:6), different anions (PSS or SS), acidic solvents (CH3COOH, HCl, H2SO4 and HClO4) and cationic additives (C8-NH2, C12-NH2 and C18-NH2), etc. Firstly, different ratios of EDOT:PSS are discussed. From cyclic voltammetry and electrochemical impedance analysis, it is known that the catalytic activity of PEDOT:PSS film for the redox pair of cobalt electrolyte will decrease with the increase of PSS concentration in the aqueous solution. Because the catalytic activity of PSS polymer is worse than that of PEDOT, in order to reduce the influence of PSS on the PEDOT films, the system of EDOT:PSS=1:1.25 was selected for comparison under different polymerization conditions in the following research. Second, we used the monomer SS of PSS as an additive, and found that SS can retain the ability of PSS to help polymerization, and can reduce the effect of PEDOT films on the catalytic activity and morphology. In the discussion of different acidic solvents, it is found that the lower the pH value, the better the polymerization ability of EDOT, but the sulfate functional group of sulfuric acid is easy to interact with PEDOT, resulting in a larger interface impedance than perchloric acid. According to the analysis of XPS, the ratio of PEDOT:SS in the film is the lowest, which means that perchloric acid can not only help EDOT polymerize but also remove excess SS, which achieve better catalytic activity and lower interfacial impedance value. Finally, the effect of molecules with amine functional group on EDOT polymerization is discussed. Since molecules with amine functional group are easily adsorbed and desorbed at different potentials, they can also help the dispersion of EDOT in aqueous solution. The PEDOT/ C12-NH2 film has the best effect because it is desorbed during the potential reverses and does not stay in the film. In this study, the PEDOT composite films were used as the counter electrode of dye-sensitive solar cells, and the photoelectric conversion efficiencies were 8.52 % (PEDOT/C12-NH2), 8.49 % (PEDOT:SS), 7.97 % ( PEDOT:PSS), and 7.87 % (PEDOT).

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