我們利用染料直立吸附於 TiO2 的特性,對染料TPCA 進行結構修飾產生具有熱聚合能力的VTPCA。藉由控制染料的排列密度,引發合聚後的染料足以防止電解質過度擴散,降低電解質的干擾,達到抑制載子復合的目的。結構未修飾的TPCA 元件僅得到4.04 %的效率,熱聚合染料VTPCA 將效率提升至5.74 %,增幅達42.1 %。 除此之外,針對TiO2 表面的活性中心距離為10Å,我們也設計了一系列具有不同結構特色的雙錨基染料,其兩錨基距離為10Å 或其整數倍,如:dTPCA、ICZDTA、BPDTA 等等。此類型染料擁有強烈的吸附力及高消光係數,對於元件的長效性與效能皆能有正面的幫助。
A simple method uses to reduce the electron recombination in dye-sensitized solar cells (DSSCs) is demonstrated. The new dye molecule VTPCA equipped with thermal cross-linkable styryl group can undergo polymerization during the annealing step of device fabrication to generate an electrolyte-blocking shell, which can impede the undesirable electron recombination with the electrolyte. The Jsc, Voc, FF of the solar cell sensitized with VTPCA are 9.83 mA cm-2, 0.74 V, and 0.73, respectively, yielding an overall conversion efficiency of 5.31 %. The result acquires 31.4 % improvement on device efficiency comparing to the unmodified device. In addition, with the incorporation of co-adsorbent chenodeoxycholic acid (CDCA) and cross-linkable repair additive 4,4’-divinyltriphenylamine (DVTP), the optimized device with a robust shell shows an overall 42.1 % enhancement over the basic model device. In addition, we have designed another series of di-anchoring dyes based on the distance of TiO2 surface active site (ie: 10 or 20 Å), such as DTPCA, ICZDTA and BPDTA. These dyes have both highly binding affinity and extinction coefficient, which are two required components to develop high efficiency DSSCs.