Achieving finely tuned phase separation and vertical distribution within the photoactive layer is crucial for enhancing charge transport, thereby significantly influencing the photovoltaic performance of organic solar cells (OSCs). In this study, a nonfullerene acceptor, denoted as HLG, is designed and synthesized by introducing hydrophobic 1,2,4,5-tetrafluoro-3-((2-ethylhexyl)oxy)benzene as the side chains. The fluorine-substituted functional groups endow HLG with higher surface energy, thereby rendering it suitable for utilization as a morphological regulator in the PB2:BTP-eC9 blends. The morphology study reveals that HLG plays an important role in the formation of a favorable phase separation and vertical phase distribution. Benefiting from the desirable morphology, the PB2:HLG:BTP-eC9-based OSC demonstrates an impressive power conversion efficiency (PCE) of 19.5%. This study introduces an effective approach that combines molecular design and the ternary strategy to optimize phase separation and vertical distribution within the active layer simultaneously, leading to significant improvements in the PCE of the OSCs.

中文翻译：

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通过分子设计和三元策略优化有机太阳能电池的相分离和垂直分布，效率达到 19.5%

在光敏层内实现精细调整的相分离和垂直分布对于增强电荷传输至关重要，从而显着影响有机太阳能电池（OSC）的光伏性能。本研究通过引入疏水性1,2,4,5-四氟-3-((2-乙基己基)氧基)苯作为侧链，设计并合成了非富勒烯受体，记为HLG。氟取代的官能团赋予 HLG 更高的表面能，从而使其适合用作 PB2:BTP-eC9 共混物中的形态调节剂。形貌研究表明，HLG 在形成有利的相分离和垂直相分布方面发挥着重要作用。受益于理想的形态，基于 PB2:HLG:BTP-eC9 的 OSC 表现出令人印象深刻的 19.5% 的功率转换效率 (PCE)。这项研究引入了一种有效的方法，将分子设计和三元策略相结合，同时优化有源层内的相分离和垂直分布，从而显着提高 OSC 的 PCE。