| 摘要: | 本研究可分為三部分，第一部分是在聚3,4-二氧乙基噻吩與聚羥甲基3,4-二氧乙基噻吩鍍液中摻混鹼修飾之碳黑進行定電位析鍍製備其複合薄膜，根據電化學阻抗圖譜與循環伏安結果得知碳黑的摻混提升薄膜導電度，且在摻混比例為1 wt%時有最佳之電致色變性質表現。另一方面，不論碳黑摻混與否，聚羥甲基3,4-二氧乙基噻吩都比聚3,4-二氧乙基噻吩有更傑出的電致色變性質表現，根據掃描式電子顯微鏡影像可推斷聚羥甲基3,4-二氧乙基噻吩之多孔性結構使其離子在薄膜中更容易移動而導致此結果。
第二部分為光電致色變元件效能最佳化，將製備之複合薄膜作為電致色變層、塗佈1-4層染敏二氧化鈦作為光陽極搭配液態電解質組裝光電致色變元件。聚羥甲基3,4-二氧乙基噻吩/碳黑之複合薄膜組裝之元件效能均優於聚3,4-二氧乙基噻吩組裝之元件，其中以塗佈3層染敏二氧化鈦光陽極之效能為最佳。
第三部分使用前面所得之最佳化元件，以1,3:2,4-二苯亞甲基山梨醇膠態電解質取代液態電解質組裝固態光電致色變元件，其電化學操作下之性能幾乎接近液態電解質之效果，但光照操作下，因其內部阻力大且去色為擴散控制，因此去色需約10分鐘且無法達到完全去色。雖然仍有不足的地方，此固態光電致色變仍較具有應用價值，其內部阻力是最需要克服的地方。
This study can be divided into three parts, and the first part is to introduce sodium hydroxide-modified carbon black to the solution of electrodeposition of poly(3,4-ethylenedioxythiophene) or poly(hydroxymethyl 3,4-ethylenedioxythiophene) to prepare the composite thin films. According to the electrochemical impedance spectroscopy and cyclic voltammetry results, introducing carbon black would enhance the conductivity of thin films. Moreover, the thin films possess the best electrochromic properties when introduce 1 wt% carbon black. On the other hand, whatever carbon black is introduced or not, poly(hydroxymethyl 3,4- ethylenedioxythiophene)’s electrochromic properties all are better than poly(3,4- ethylenedioxythiophene)’s due to its porous microstructure.
The second part is to optimize of photoelectrochromic device. We employ the composite thin films as electrochromic layer, one to four layer of dye-sensitized TiO2¬ as photoanode, and liquid electrolyte to assemble photoelectrochromic device. The device of poly(hydroxymethyl 3,4- ethylenedioxythiophene) is better than that of poly(3,4- ethylenedioxythiophene) at all aspects. Among these, that the optimized device is constituted of poly(hydroxymethyl3,4- ethylenedioxythiophene) with three layers of dye-sensitized TiO2.
In the third part, we utilize the optimized photoelectrochromic device that was found out, and employ 1,3:2,4-Dibenzylidene sorbitol as solid electrolyte to replace the liquid one. Under electrochemical operation, it performs almost as same as the liquid one did. But under illuminated operation, it requires ten minutes to bleach and can’t reach completely bleached, due to higher internal resistance and diffusion control of bleaching. Although the improvement of this solid photoelectrochromic device is still necessary, is possesses high potential for future applications. |
