染料敏化太陽能電池(Dye-sensitized solar cells，DSCs)，由於其光電轉換機制的獨特性、材料的多樣性、元件的低製造成本與良好的光電轉換效率，相關研究極為眾多，其中，使用雙吡啶配位的釕錯合物染料因為可使元件同時具有高效率與高穩定性而備受重視，儘管如此，該類型染料的研發至今仍無法有效增加分子在近紅外光的吸收能力。本研究為求突破此限制，設計合成兩個新的雙吡啶配位釕錯合物(CYC-53及CYC-55)，其分子設計不僅採用芳香雜環同時延長輔助配位基與固著配位基的共軛長度，在固著配位基更首次分別引入selenophene及thienothiophene單元。與固著配位基使用thiophene共軛單元的CYC-21相比，CYC-53及CYC-55在DMF溶液中的吸收光譜皆紅位移、吸收強度也增加 (CYC-53及CYC-55的起始吸收波長比CYC-21 (747 nm)分別紅位移了19 nm及14 nm)。而從電化學氧化峰得知三者的HOMO位能皆為+0.84 V (vs. NHE)，透過搭配吸收光譜所得之能隙可得知：CYC-53的LUMO位能(-0.78 V vs. NHE)、CYC-55的LUMO位能(-0.79 V vs. NHE)皆低於CYC-21之LUMO位能(-0.82 V vs. NHE)。在所敏化元件的效率比較中，CYC-53及CYC-55的Jsc值均大於CYC-21 (11.61 mA·cm-2)所敏化之元件，且其中以CYC-55所敏化之元件具最高效率(6.85%)，此結果顯示在釕錯合物染料分子的固著配位基引入重原子及延長共軛單元，能夠有效降低釕錯合物的能隙、拓寬吸光範圍、與提高吸收係數，以利進一步提高所敏化元件的光電轉換效率。;Dye-sensitized solar cells (DSCs) have attracted significant attention due to their unique working mechanism, diverse materials, low manufacturing costs, and good efficiency. Bipyridyl ruthenium (Ru)-based sensitizers have received considerable attention for attending high efficiency and stability of the corresponding DSCs. However, to date, their development has not effectively increased the near-infrared light absorption capacity. To breakthrough this limitation, two new bipyridyl Ru complexes (CYC-53 and CYC-55) are designed and synthesized. They have the heterocycles to simultaneously extend the conjugation length of both ancillary and anchoring ligands. Additionally, for the first time, selenophene and thienothiophene moieties are introduced in the anchoring ligands to extent their conjugate length. Compared with CYC-21 (747 nm) using thiophene in the anchoring ligand, CYC-53 and CYC-55 in DMF exhibit a red-shifted (by 19 nm and 14 nm, respectively), and increased absorption intensity. Moreover, all of the three complexes have the same HOMO energy level of +0.84 V (vs. NHE). LUMO energy levels for CYC-53 (-0.78 V vs. NHE) and CYC-55 (-0.79 V vs. NHE) are lower than that of CYC-21 (-0.82 V vs. NHE). Both of CYC-53 and CYC-55 dyed DSCs exhibit higher Jsc values than that based on CYC-21 (11.61 mA·cm-2). CYC-55-sensitized device achieves the highest efficiency of 6.85%. These results indicate that introducing heavy atoms and extending the conjugation length in the anchoring ligands of Ru complexes can effectively reduce the energy gap, broaden the absorption profile, and enhance the absorption coefficient, thereby improving the power conversion efficiency of the correspondry devices.
