本篇論文透過Stille偶合反應、Vilsmeier-Haack醛化反應、Knoevenagel縮合反應等化學方法合成接有不同的共軛架橋連接兩個電子受體的硫二苯胺 (phenothiazine) 電子予體之YL系列雙錨基有機染料，可作為染敏太陽能電池之光敏染料。我們引入像螺旋槳狀的非平面四苯基乙烯基 (tetraphenylethylene) 於硫二苯胺電子予體上，除了可抑制YL染料分子之π‒π堆疊外，也期待能使染料分子在TiO2表面上能夠呈現較緊密的排列，搭配雙錨基結構，可以更有效的抑制暗電流。 這些具有四苯基乙烯基結構的YL染料吸光範圍在300‒600nm，莫耳消光係數最高可以達到70000 M-1cm-1以上。經由電化學和光化學數據計算得到染料的HOMO （5.37至5.47 eV）和LUMO（3.26至3.31 eV）確認染料能將電子注入到TiO2及能夠被電解質還原。而YL染料的光電轉換效率在模擬的AM 1.5 G照明下為3.94至7.11%，在6000 lux下為8.64至11.45%。其中，共軛架橋為3-己基噻吩的YL-2在1 sun和弱光下都有最好的表現，在1 sun光照下達N719標準元件之81%。 ;A series of new di-anchored organic dyes containing a tetraphenylethylene tethered phenothiazine core (YL) featuring with different π-bridging units (thiophene, 3-hexylthiophene, 4-hexyl-2, 2’-thiophene, cyclopenta[1,2-b:5,4-b′]dithiophene) have been synthesized via Stille coupling, Vilsmeier-Haack formylation and Knoevenagel condensation reactions, and used as the sensitizers of dye-sensitized solar cells (DSSCs). Incorporation of a nonplanar TPE entity with propeller-like configuration is beneficial to suppressing π‒π aggregation of the dye molecules. Besides, TPE-induced more compact dye packing on TiO2 surface in collaboration with double anchors are expected to more effectively suppress the dark current of DSSCs. These new dyes have electronic absorption raging from 300 to 600 nm, with the highest molar coefficient surpassing 70000 M-1cm-1. The HOMO (5.37 to 5.47 eV) and LUMO (3.26 to 3.31) energy levels of the dyes calculated from the electrochemical and photochemical data assure sufficient thermodynamic driving force for electron ejection and regeneration. The light to electricity conversion efficiency of YL dyes ranges from 3.94 to 7.11% under simulated AM 1.5 G illuminations and from 8.64 to 11.45% under 6000 lux. Among them, the YL-2 which a 3-hexylthiophene spacer in the π-conjugated bridgunites between the donor and the acceptor has the best efficiency under 1 sun, reaching 81% of N719-based standard cell.
