While the power conversion efficiencies (PCEs) of organic solar cells (OSCs) have been dramatically increased through the development of small molecular acceptors (SMAs), achieving eco-friendly solution processability of OSCs is a crucial prerequisite for their practical application. In this study, we develop three new, green solvent-processable SMAs (YSe–C3, YSe–C6, and YSe–C9) with different outer side-chains (n-propyl (C3), n-hexyl (C6), and n-nonyl (C9)), affording high-performance OSCs with non-halogenated solvent (o-xylene)-processed active layers. Also, the impact of both outer and inner side-chain engineering of these SMAs on the performance of eco-friendly fabricated OSCs is systematically investigated. The outer side-chain structure has a much more significant impact than the inner side-chain. For example, the PM6:YSe–C6 blend affords high-performance OSCs with a power conversion efficiency (PCE) of over 16%, whereas the PCEs of the YSe–C3- and YSe–C9-based OSCs are only 11–14%. The lower PCEs of PM6:YSe–C3 and C9 are mainly attributed to reduced electron mobility and increased charge recombination, resulting from aggregate-containing non-optimal blend morphologies. Interestingly, the well-optimized morphology of the YSe–C6-based blend also affords OSC devices with active layer thickness-independent PCEs, up to a thickness of >400 nm, demonstrating the great potential for large-area device manufacturing via an eco-friendly printing process. Thus, optimizing the outer side-chain structure of Y-series SMAs is essential for producing green solvent-processed high-performance OSCs.

中文翻译：

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通过外部侧链选择掺有硒酚的 Y 系列受体实现绿色溶剂处理的高性能有机太阳能电池

虽然通过小分子受体 (SMA) 的开发，有机太阳能电池 (OSC) 的功率转换效率 (PCE) 已显着提高，但实现 OSC 的环保溶液加工性能是其实际应用的关键先决条件。在这项研究中，我们开发了三种具有不同外侧链（正丙基（C3）、正己基（C6）和n -壬基 (C9))，提供具有非卤化溶剂 ( o-二甲苯）处理的活性层。此外，系统研究了这些 SMA 的外部和内部侧链工程对环保制造的 OSC 性能的影响。外侧链结构的影响比内侧链要大得多。例如，PM6:YSe-C6 混合物可提供功率转换效率 (PCE) 超过 16% 的高性能 OSC，而基于 YSe-C3 和 YSe-C9 的 OSC 的 PCE 仅为 11-14% . PM6:YSe-C3 和 C9 较低的 PCE 主要归因于电子迁移率降低和电荷复合增加，这是由于含有聚集体的非最佳混合形态造成的。有趣的是，基于 YSe-C6 混合物的优化形态也为 OSC 器件提供了与有源层厚度无关的 PCE，厚度可达 >400 nm，通过环保印刷工艺。因此，优化 Y 系列 SMA 的外侧链结构对于生产绿色溶剂处理的高性能 OSC 至关重要。