We report the synthesis, characterization, and photovoltaic properties of four ruthenium complexes (CI101, CBTR, CB111, and CB108) having various N-heterocyclic carbene ancillary ligands, pyridine-imidazole, -benzimidazole, -dithienobenzimidazole, and -phenanthroimidazole, respectively. These complexes were designed to investigate the effect of extended conjugation ordained from ring fusion on the power conversion efficiencies of the solar cells. The device sensitized by CB108, the pyridine-phenanthroimidazole conjugated complex, showed an improved efficiency (9.89%) compared to those of pyridine-benzimidazole conjugated system (CBTR, 9.72%) and the parent unfused ring system (CI101, 6.24%). Surprisingly, the sulfur-incorporated pyridine-dithienobenzimidazole system (CB111, 9.24%) exhibited a little lower efficiency than that of N719 (9.41%). The enhanced photovoltaic performance of CB108 was mainly attributed to the increase in electron lifetime and diffusion length confirmed by the electrochemical impedance spectroscopy.

中文翻译：

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N杂环碳基增敏剂的共轭扩展对染料敏化太阳能电池性能的影响

我们报告了四个钌配合物（CI101，CBTR，CB111和CB108）的合成，表征和光电性质，这些配合物分别具有各种N-杂环卡宾辅助配体，吡啶-咪唑，-苯并咪唑，-二噻吩并苯并咪唑和-菲并咪唑。设计这些配合物以研究环融合法所规定的扩展共轭对太阳能电池功率转换效率的影响。通过敏化的装置CB108中，吡啶菲并缀合复合物，显示出相比，这些吡啶并咪唑的共轭系统（的改进的效率（9.89％）CBTR，9.72％）和母未融合的环系统（CI101，6.24％）。令人惊讶的是，掺硫吡啶-二硫代间苯并咪唑体系（CB111，9.24％）的效率略低于N719（9.41％）。CB108的增强的光伏性能主要归因于电子寿命和扩散长度的增加，这是由电化学阻抗谱确定的。