In this work, three new nonfullerene acceptors (BT₆IC-BO-4Cl, BT₆IC-HD-4Cl, and BT₆IC-OD-4Cl), which comprise a central fused benzothiadiazole core and two dichlorinated end groups and substituted with different branched alkyl chains [2-butyloctyl (BO), longer 2-hexyldecyl (HD), and 2-octyldodecyl (OD)], are successfully designed and prepared. The influences of the branched alkyl chain with different lengths on the electronic/optoelectronic property, electrochemistry, and photovoltaic performance are systematically investigated. It has been revealed that BT₆IC-HD-4Cl, which had the medium alkyl chain (2-hexyldecyl) length, has the best photovoltaic performance when using PDBT-TF as the electron donor. The BT₆IC-HD-4Cl-based device shows an impressive power conversion efficiency of 14.90%, much higher than BT₆IC-BO-4Cl (14.45%)- and BT₆IC-OD-4Cl (9.60%)-based devices. All these evidence shows that the subtle changes in the alkyl substituent of these high-performance chlorinated acceptors can have a big impact on the structural order and molecular packing of the resultant nonfullerene acceptors and ultimately on the photovoltaic performance of the final solar devices.

中文翻译：

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烷基链和氯化工程对高性能非富勒烯受体的协同作用。

在这项工作中，三个新的非富勒烯受体（BT ₆ IC-BO-4Cl，BT ₆ IC-HD-4Cl和BT ₆ IC-OD-4Cl）包括一个中心稠合的苯并噻二唑核心和两个二氯端基，并被取代成功设计并制备了不同的支链烷基链[2-丁基辛基（BO），更长的2-己基癸基（HD）和2-辛基十二烷基（OD）]。系统地研究了不同长度的支链烷基链对电子/光电性能，电化学和光伏性能的影响。据透露，BT ₆ IC-HD-4Cl当使用PDBT-TF作为电子供体时，具有中等烷基链（2-己基癸基）长度的，具有最佳的光伏性能。基于BT ₆ IC-HD-4Cl的设备显示出令人印象深刻的功率转换效率14.90％，远高于基于BT ₆ IC-BO-4Cl（14.45％）和BT ₆ IC-OD-4Cl（9.60％）的功率转换效率设备。所有这些证据表明，这些高性能氯化受体的烷基取代基的细微变化可能对所得非富勒烯受体的结构顺序和分子堆积以及最终太阳能电池的光伏性能产生重大影响。