The advent of next-generation nonfullerene acceptors (NFAs) has propelled major advances in organic solar cells (OSCs). Here we report an NFA design incorporating CF₃-terminated side chains having varying N-(CH₂)_n-CF₃ linker lengths (n = 1, 2, and 3) which introduce new intermolecular interactions, hence strong modulation of the photovoltaic response. We report a systematic comparison and contrast characterization of this NFA series with a comprehensive set of chemical/physical techniques versus the heavily studied third-generation NFA, Y6, revealing distinctive and beneficial properties of this new NFA series. Single-crystal diffraction analyses reveal unusual two-dimensional mesh-like crystal structures, featuring strong interactions between the side chain CF₃-terminal and NFA core F substituents. These atomistic and morphological features contribute to enhanced charge mobility and significantly enhanced photovoltaic performance. We show that varying the CF₃-terminated side chain linker length strongly modulates light harvesting efficiency as well as charge recombination and the photovoltaic bandgap. The CF₃-(CH₂)₂-based OSC demonstrates the most balanced performance metrics, achieving a remarkable 19.08% power conversion efficiency and an exceptional 80.09% fill-factor. These results imply that introducing CF₃-terminated side chains into other OSC conjugated constituents may accelerate next-generation solar cell development.

中文翻译：

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非富勒烯受体中的 CF3 官能化侧链促进了高效有机太阳能电池的静电相互作用


下一代非富勒烯受体 （NFA） 的出现推动了有机太阳能电池 （OSC） 的重大进步。在这里，我们报告了一种 NFA 设计，其中包含具有不同 N-（CH₂）_{n-CF 3} 接头长度（n = 1、2 和 3）的 CF₃ 封端侧链，这引入了新的分子间相互作用，因此对光伏响应进行了强调节。我们报告了该 NFA 系列与经过大量研究的第三代 NFA Y6 的系统比较和对比特征，揭示了该新 NFA 系列的独特和有益特性。单晶衍射分析揭示了不寻常的二维网状晶体结构，其特点是侧链 CF₃ 端和 NFA 核心 F 取代基之间存在很强的相互作用。这些原子和形态特征有助于增强电荷迁移率并显著提高光伏性能。我们表明，改变 CF₃ 端接侧链接头的长度强烈调节光收集效率以及电荷复合和光伏带隙。基于 CF₃-（CH₂）₂ 的 OSC 展示了最平衡的性能指标，实现了卓越的 19.08% 的功率转换效率和出色的 80.09% 填充因子。这些结果表明，将 CF₃ 端接侧链引入其他 OSC 共轭成分可能会加速下一代太阳能电池的开发。