Abstract The present work aimed to find the answer how does the isomerization of the Ru based dyes affect the overall photon-to-current efficiency of the DSSCs and to explain the charge transfer phenomenon occurring on the dye/nanosemiconductor interface. Therefore, electronic and optical properties of three bipyridine derivatives anchored on the TiO2 electrode were investigated by computational simulations based on quantum chemistry codes performed on a cluster model and the predictions compared with experimental responses. The quantum chemical calculations carried out for the para-, meta- and ortho-isomers has given the possibility to explain the role of an anchor group position in the DSSC devices design. An in-depth analysis of the obtained data shows that the nature of the bonding between the anchor groups and the semiconducting nanoparticles affects the charge transfer at the interfaces. The electronic properties obtained for the hybrid systems and their components indicate that solar cells with the para-derivatives of the Ru based dyes as sensitizers exhibit the highest photo conversion efficiency. The observed phenomenon was explained based on the photogenerated excitons in the organic groups and their dissociation at the dye/semiconductor interfaces to ensure the free charge carriers.

中文翻译：

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染料异构化效应对染料/纳米半导体界面电荷转移现象的影响

摘要 目前的工作旨在找到答案，Ru 基染料的异构化如何影响 DSSC 的整体光子到电流效率，并解释染料/纳米半导体界面上发生的电荷转移现象。因此，通过基于在簇模型上执行的量子化学代码的计算模拟以及与实验响应相比的预测，研究了锚定在 TiO2 电极上的三种联吡啶衍生物的电子和光学性质。对位异构体、间位异构体和邻位异构体进行的量子化学计算可以解释锚定基团位置在 DSSC 器件设计中的作用。对所得数据的深入分析表明，锚定基团和半导体纳米颗粒之间的键合性质影响界面处的电荷转移。从混合系统及其组件获得的电子特性表明，以 Ru 基染料的准衍生物作为敏化剂的太阳能电池表现出最高的光转换效率。观察到的现象是基于有机基团中的光生激子及其在染料/半导体界面处的离解来解释的，以确保自由载流子。