Department of Chemistry, Yonsei University, Seoul, 120-749 (Korea).
Education Center for Global Leaders in Molecular Systems for Devices, Kyushu University, Fukuoka 819-0395 (Japan).
ChemSusChem. 2015 Sep 7;8(17):2967-77. doi: 10.1002/cssc.201500085. Epub 2015 Mar 6.
A series of new β-functionalized push-pull-structured porphyrin dyes were synthesized so as to investigate the effect of the π-conjugated spacer on the performance of dye-sensitized solar cells (DSSCs). Suzuki- and Heck-type palladium-catalyzed coupling methodologies were used to obtain various β-functionalized porphyrins and β-benzoic acid (ZnPHn) and β-vinylbenzoic acid (ZnPVn) derivatives from β-borylated porphyrin precursors. Photophysical studies of the resulting porphyrins revealed a clear dependence on the nature of the β linker. In particular, it was found that a β-vinylene linkage perturbs the electronic structure of the porphyrin core; this is less true for a β-phenyl linkage. Theoretical analyses provided support for the intrinsic intramolecular charge-transfer character of the β-functionalized, push-pull porphyrins of this study. The extent of charge transfer depends on the nature of the β-conjugated linkage. The photovoltaic performances of the cells sensitized with β-phenylenevinylene ZnPVn exhibited higher power conversion efficiency values than those bearing β-phenyl linkages (ZnPHn). This was ascribed to differences in light-harvesting efficiency. Furthermore, compared to the use of a standard iodine-based electrolyte, the DSSC performance of cells made from the present porphyrins was improved by more than 1 % upon using a cobalt(II/III)-based electrolyte. Under standard AM 1.5 illumination, the highest efficiency, 8.2 %, was obtained by using cells made from the doubly β-butadiene-linked porphyrin.
一系列新型的β-功能化推挽结构卟啉染料被合成，以研究π共轭间隔基对染料敏化太阳能电池（DSSC）性能的影响。Suzuki 和 Heck 型钯催化偶联方法被用于从β-硼酸卟啉前体中获得各种β-功能化卟啉和β-苯甲酸（ZnPHn）和β-乙烯基苯甲酸（ZnPVn）衍生物。所得卟啉的光物理研究清楚地表明了β连接基的性质的依赖性。特别是，发现β-亚乙烯基键会干扰卟啉核心的电子结构；而β-苯基键的情况则不那么真实。理论分析为该研究中β-功能化推拉卟啉的固有分子内电荷转移特性提供了支持。电荷转移的程度取决于β-共轭键的性质。用β-亚苯基乙烯基 ZnPVn 敏化的电池的光电性能表现出比具有β-苯基键的电池更高的功率转换效率值。这归因于光捕获效率的差异。此外，与使用标准碘基电解质相比，使用本卟啉制成的电池的 DSSC 性能在使用钴（II/III）基电解质时提高了 1%以上。在标准 AM 1.5 光照下，使用双β-丁二烯连接的卟啉制成的电池获得了 8.2%的最高效率。
