可交聯型釕金屬錯合物與其交聯劑在染料敏化太陽能電池之應用

Abstract

本研究合成一帶有可進行聚合反應之苯乙烯官能基的釕金屬染料Ru(4,4’-dicarboxylic acid) (4,4'-bis((4-vinylbenzyloxy)methyl) -2,2'- bipyridine)(NCS)2 簡稱 Ru-S 。利用NMR、IR、UV-Vis光譜等方式鑑定其結構，並進一步以UV-Vis光譜測試其吸附在TiO2表面後以Glycerol propoxylate triacrylate(GPTA)進行共聚合反應後的脫附實驗，探討其與TiO2鍵結的穩定性。在太陽能電池元件的表現上，以3-methoxypropyl nitrile (MPN)為溶劑的液態電解質時以不同濃度的GPTA進行表面聚合改質後，可以將原本7.53%的效率分別提升至7.88%。而以polymethacrylate膠態電解質製備的元件則能將效率從6.96%增加至7.57%。 另一部分則以改變液態電解質中Li+的濃度來觀察以GPTA表面改質前後的電池表現。 在缺乏或低濃度Li+的液態系統中，表面聚合改質皆可以在最佳化濃度下呈現出比原本較高的效率表現。 但在高濃度的Li+電解質下，由於改質後元件的短路電流提升效果不明顯，且Voc下降，造成效率並未得到改善。 從吸附在TiO2上Ru-S染料的IR光譜實驗可證明Ru-S染料本身即具有螯合Li+減緩因提高Li+濃度造成Voc下降的能力。量測IMPS/IMVS時發現，隨著LiI濃度提升，電子收集效率也會愈高，證明Li+有加速I-/I3-移動的能力。最後，我們選用PMA膠態電解質進行封裝，量測元件的長效性。於室溫下經過一個月發現效率仍可保有原先水準，唯獨以AIBN起始劑交聯的Crosslinked Ru-S的效率會略降。

We synthesized the crosslinkable ruthenium complex with styryl groups attached on the bipyridine ligand, denoted as Ru-S which was characterized by NMR, IR, and UV-Vis spectroscopies. Its stability after crosslinking and copolymerization with Glycerol propoxylate triacrylate(GPTA) were measured by UV-Vis spectroscopy. By using the MPN based liquid electrolyte, the efficiency of DSSCs crosslinking with proper amounts GPTA increased from 7.53% to 7.88%. However, using the PMA-gelled electrolyte system, the device performance was raised from 6.96% to 7.57%. On the other hands, the DSSC with GPTA-crosslinked Ru-S dye and with various Li+ concentrations in liquid electrolytes were studied. At low Li+ concentration, the efficiency was increased with the content of Li+. However, at high Li+ concentration, although the short current was slightly increased with the content of Li+ but the Voc was decreased, leading to lower power efficiency. The Li+-coordination capability of Ru-S was then investigated by IR spectroscopy, which was used to explain the slow decreasing trend of Voc as the Li+ concentration was increased in the electrolyte system.