The intermolecular charge transfer (CT) exciton in the merocyanine:[6,6]-phenyl-C₆₁-butyric acid methyl ester (PC₆₁BM) system induced by the molecular geometry is investigated. The CT state, localized on the merocyanine domain, was experimentally observed in the transient spectra and modeled via DFT/TDDFT calculations. A relationship between molecular geometry at the donor/acceptor interface and the delocalization of the CT exciton was identified. It was found that different alkyl side chains of merocyanine can be used to tune the formation of H-aggregates by means of better intermixing with PC₆₁BM. Moreover, we observed that high H aggregation increases the charge delocalization and improves the efficiency and carrier transport properties of the merocyanine-based bulk heterojunction solar cell.

中文翻译：

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界面分子结构组织对花菁：PC ₆₁ BM共混物中电荷转移态形成和激子离域的影响

研究了由分子几何结构诱导的花菁：[6,6]-苯基-C _61-丁酸甲酯（PC ₆₁ BM）体系中的分子间电荷转移（CT）激子。在瞬态谱中通过实验观察到了位于花菁域上的CT状态，并通过DFT / TDDFT计算进行建模。确定了供体/受体界面处的分子几何形状与CT激子的离域之间的关系。已发现，通过与PC ₆₁更好地混合，可以使用花青素的不同烷基侧链来调节H聚集体的形成。BM。此外，我们观察到高的H聚集会增加电荷离域，并改善基于花菁的本体异质结太阳能电池的效率和载流子传输性能。