Quantification of the Effects of Recombination and Injection in the Performance of Dye-Sensitized Solar Cells Based on N-Substituted Carbazole Dyes
Quantification of the Effects of Recombination and Injection in the Performance of Dye-Sensitized Solar Cells Based on N-Substituted Carbazole Dyes
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DOI：
10.1021/jp1055842
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发表时间：
2010-11-25
影响因子：
3.7
通讯作者：
Bisquert, Juan
中科院分区：
文献类型：
--
作者：
Barea, Eva M.;Zafer, Ceylan;Bisquert, Juan
设计了两种用于染料敏化太阳能电池的新型敏化剂，由 N-芳基咔唑不对称功能化的噻吩单元组成。二(叔丁基)咔唑部分作为电子供体基团，噻吩链作为桥基，氰基丙烯酸作为锚定基团和电子受体基团。共轭长度的增加产生两个主要效果：首先，它导致染料的光吸收红移，从而改善吸收与太阳光谱的重叠。其次，氧化电位降低。使用含有碘化物/三碘化物氧化还原对的电解质研究了这组染料作为介孔 TiO2 太阳能电池中敏化剂的光伏性能。具有最佳吸收特性的染料表现出最高的光电流，但由于复合损失较多，开路电压较低。使用基于β重组模型的分析程序演示了结构（分子染料大小）和重组之间的趋势，该模型结合了阻抗谱和密度电流-电压数据。
Two new sensitizers for dye sensitized solar cells have been designed consisting of thiophene units asymmetrically functionalized by N-aryl carbazole. The di(tert-butyl) carbazole moieties acts as an electron donor group, the thiophene chain as a bridge group, and the cyanoacrylic acid as an anchoring and electron acceptor group. An increase of the conjugation length produces two main effects: first, it leads to a red-shift of the optical absorption of the dyes, resulting in an improved overlap of the absorption with the solar spectrum. Second, the oxidation potential decreases. The photovoltaic performance of this set of dyes as sensitizers in mesoporous TiO2 solar cells was investigated using electrolytes containing the iodide/triiodide redox couple. The dye with the best absorption characteristics showed the highest photocurrent but lower open circuit voltage due to more losses by recombination. A trend between structure (molecule dyes size) and recombination is demostrated using an analysis procedure based on beta-recombination model that combines impedance spectroscopy and density current-voltage data.