由於全球暖化以及石化能源短缺的問題，使再生能源受到廣泛的注意。太陽能具有取之不盡，用之不竭的優勢，利用太陽能電池將光能轉為電能為眾所矚目的研究。染料敏化太陽能電池(dye-sensitized solar cells, DSSCs)具有透光性、可撓曲性、色彩多樣性、良好的光電轉換效率及低製造成本等優點，是目前相當熱門的研究領域之一，也是未來前景極為看好的新興科技。DSSCs中，光電流主要來源-光敏化劑(sensitizer)，是影響電池光電轉換效率以及元件穩定性的關鍵組成之一。DSSCs所採用的主要染料：以釕金屬為中心的錯合物以及有機共軛分子，皆具有高光電轉換效率(10-11 %)；僅管如此，這些染料仍無法有效的吸收遠紅光(far-red (FR) region)及近紅外光區(near-infrared (NIR) region)的光子，為了進一步的提高染料敏化太陽能電池的光電轉換效率，發展新型的FR/NIR染料是相當重要的。Squaraine染料具有高吸收係數且吸收的最大波長位於遠紅光/近紅外光區，是設計NIR染料的最佳選擇之一。本研究在設計合成幾個含squaraine單元染料分子:JYL-SQ1、JYL-SQ2、THL-SQ3、JYL-SQ5、JYL-SQ6及JYL-SQ7，採用donor-π-conjugated-acceptor的設計概念，同時以thiophene或其衍生物做為具有推電子能力的共軛片段來製備不對稱型squaraine染料，論文中詳細探討這些染料的物理性質，並將之組裝成DSSCs元件，測試元件的光電效能，以了解染料分子結構、物理性質與其所組裝之元件效率的關係。 Global warming and depletion of fossil fuels have led to a great interesting in clean renewable energy sources. Amongst the new energy technologies, solar cell which utilizes the Sun as an energy source is one of the most promising technologies. Dye-sensitized solar cell, DSSC, is considered as an alternative to the conventional solar cell due to its transparence, flexibility, colorfulness, high conversion efficiency and low cost. Sensitizer is one of the key components for the photovoltaic performance and long-term stability of DSSCs. Ruthenium complexes and organic dyes exhibit relatively high efficiency, however those photo-sensitizers did not absorb the photons in the Far-Red (FR) or Near-Infrared (NIR) region. To improve the performances of DSSCs, it would be essential to develop FR/NIR sensitizer. Squaraine dyes with attractively intrinsic absorption of the red-light photons and unusual high molar extinction coefficient were developed for the application in DSSCs. In this study we designed and synthesized several new donor-π conjugated- acceptor (D-π-A) unsymmetrical squaraine dyes, coded JYL-SQ1, JYL-SQ2, THL-SQ3, JYL-SQ5, JYL-SQ6 and JYL-SQ7, in which thiophene derivatives were incorporated to link the squaraine core and donor moiety. The fundamental physcicochemical properties of these squaraine dyes and the corresponding DSSCs devices based on them were well-studied. Understanding the relationship between the structure of the squaraine dyes, their physical properties and photovoltaic performance of the corresponding DSSCs devices may provide a new way for designing new high efficiency FR/NIR sensitizers.
