本論文成功合成出以 thienoisoindigo 為結構中心主體合成出兩個新穎小分子，可作為有機光伏打電池的光敏材料。我們以thienoisoindigo 作為分子的拉電子基 (acceptor)，搭配使用具有電子豐盈的 ditolylaminothienyl 與 diphenylamino- phenylen-1-yl 作為分子的推電子基 (donor)，藉由 Pd 金屬催化之 Stille 偶合反應合成出具對稱結構 (D-A-D) 分子。經紫外光-可見光-紅外線光譜測量得知W1分子具有相對小的能隙 (band gap) 與相當高的光吸收強度 (55794 M-1‧cm-1)，吸光範圍涵蓋400 - 1000 nm，為很難得少見的可吸收近紅外光的有機太陽能電池染料。比較其他以相同結構主體之有機小分子染料，發現我們所設計的 W1 分子不僅在溶液吸收光譜是這系列 thienoisoindigo 染料之中吸收最紅移且吸光係數最高；且其 HOMO/LUMO 能階差也與元件相對材料可以搭配，很有機會在做成元件後得到好的光電轉換效率。 Two new thienoisoindigo-based near-infrared small molecules (W1, W2) were designed and synthesized for small-molecule organic solar cells. These compounds possess a donor-acceptor-donor molecular architecture, which is composed by two identical electron-donating moieties connected to an electronwithdrawing thienoisoindigo moiety. They are characterized by 1H NMR, 13C NMR and mass spectrometry, and their photophysical, electrochemical properties as well as energy levels were studied by using UV-visible-NIR spectrometer, fluorescent spectrometer and cyclic voltammetry, respectively. The experimental results show that W1 has high molar extinction coefficient (55794 M-1‧cm-1), and a broad, red-shifted absorption spectra extending into near-infrared region (400 - 1000 nm), which makes it a good candidate for organic solar cell applications.
