三聚茚基光敏剂的设计、合成及其光伏性能研究

Dye-sensitized solar cells (DSC) have became one of the important research areas in the filed of photovoltaic applications. To promote the power conversion efficiency of DSC, synthesis of high efficiency photosensitizers is one of the key "bottleneck". In the study of Youth Science Fund Project, we found that the truxene-based photosensitizers pose strong light-capturing abilities apart from their suppressing photosensitizer aggregation and retarding charge recombination. In addition, this type of photosensitizers exhibit good photovoltaic performance of dye-sensitized solar cells using cobalt polypyridine redox couples. These findings have been published in Chem. Soc. Rev.，Chem. Commun.，Org. Lett.，J. Phys. Chem. C and other journals. However, the photo-current of the truxene-based photosensitizers need to be further improved. Moreover, the work mechanisms of truxene-based photosensitizers in the DSC employing the cobalt polypyridine redox couples are not clear. Based on these considerations, a series of the truxene-based photosensitizers with strong electron-donoring capability will be synthesized. To clarify the related interface process mechanism, and reveal the rule of photosensitizer structure-activity relationship in the DSCs employing the cobalt polypyridyl redox couples, our research will focus on the interaction rules between the truxene-based photosensitizers and the cobalt polypyridine redox couples. This plan provides experimental and theoretical foundation of the design and synthesis of high efficiency photosensitizers for DSC. Furthermore, it is important for deeper understanding of the light-electricity conversion process and principle in DSC.

染料敏化太阳能电池(DSC)已经成为太阳能光伏应用领域的研究热点。在提高DSC光电转换效率方面，高效光敏剂的制备是关键“瓶颈”之一。在青年科学基金项目中，我们发现三茚基光敏剂具有光捕获能力强，抑制光敏剂聚集和电子复合等优点，在钴多吡啶电解质体系中表现出优良的光伏性能。研究成果在Chem. Soc. Rev.，Chem. Commun.，Org. Lett.，J. Phys. Chem. C等刊物上发表。然而，该类光敏剂的光电流还需进一步提高。此外，三聚茚基光敏剂在钴多吡啶电解质体系DSC中的诸多工作机理还不十分清楚。据此，本项目拟合成供电能力强的三聚茚基光敏剂；并重点研究光敏剂与钴多吡啶电解质的相互作用的规律，阐明相关的界面过程机理，以揭示基于钴多吡啶电解质体系的光敏剂构效关系规则。本项目为高效光敏剂的设计合成提供实验和理论依据，对深入理解DSC光-电转换基本过程与原理具有重要意义。

染料敏化太阳能电池(DSC)已经成为太阳能光伏应用领域的研究热点。在提高DSC光电转换效率方面，高效光敏剂的制备是关键“瓶颈”之一。本项目合成了系列非对称三聚茚基三芳胺供电基团和氮吡咯噻吩共轭桥，用于构筑有机光敏剂；采用不同的钴电解质研究光敏剂与钴多吡啶电解质的相互作用规律。. 研究发现，三聚茚可有效抑制电子复合，引入芳胺或者噻吩衍生物作为二级供电基团，可有效调控染料的光伏性能。其中，以咔唑为二级供电基团，可以有效提高三聚茚光敏剂的光电流；值得注意的是，我们的结果证明了噻吩衍生物不仅是优良的共轭桥，也可以是优良的二级供电基团。取代基对氮吡咯噻吩光谱影响较小，主要影响光敏染料的空间排布。通过扩大氮吡咯横向共轭体系可以有效调节光敏染料的能级，光谱以及光伏性能。其中，噻吩并吡咯噻吩具有高摩尔吸光系数，且边缘烷基链可以有效控制电池中的电子复合。以三聚茚三芳胺为供电基团，以氮吡咯噻吩为共轭桥，M60在标准光强照射下获得了9.75%的光电转换效率。我们的研究还发现，染料抑制电子复合的能力会影响到钴（III）离子的复合规律，而不仅仅是由电子复合驱动力大小来决定的。对于钴基电解质染料敏化太阳能电池来说，要获得高光电转换效率，光敏染料的抑制电子复合能力时第一位的，在染料具有良好的抑制电子复合能力情况下，光吸收能力而非染料再生驱动力是获得高电流的关键。. 本项目为基于钴基电解质的高效光敏剂的设计合成提供实验和理论依据，对深入理解DSC光-电转换基本过程与原理具有重要意义。