Research has shown that ternary strategy is an effective tool for improving the performance of organic solar cells (OSCs) and simple-structured small molecules with low-cost and wide bandgap which broadens the scope of the choice in third components recently attracted the attention of researchers. Herein, a small molecule with benzo[1,2-b:4,5-b’]dithiophene (BDT) core named BR-C12 which mixed well with PM6 has been designed and synthesized. Incorporating BR-C12 as third component into PM6:Y6, BR-C12 exhibits a complementary absorption with PM6 and Y6, promoted exciton dissociation and charge collection, reduced bimolecular recombination, resulting in more ordered molecular packing. The PM6:Y6:BR-C12 (1:1.2:0.1, weight ratio) OSC shows an improved power conversion efficiency (PCE) of 17.02% in comparison to host binary devises (16.42%). In addition, by employing BR-C12 as third component into PM6:L8-BO, the ternary device based on PM6:L8-BO:BR-C12 also achieves significant enhancement in device photovoltaic performance with a PCE of 18.26%. In addition, BR-C12-added ternary devices exhibit improved stability than binary ones. This work presents a method for constructing high-performance ternary OSCs and enriches the abundance of materials for the third components.

研究表明，三元策略是提高有机太阳能电池（OSC）性能的有效工具，结构简单、低成本、宽带隙的小分子扩大了第三元器件的选择范围，最近引起了研究人员的关注. 在此，设计并合成了一种以苯并[1,2-b:4,5-b']二噻吩（BDT）为核心的小分子BR-C12，它与PM6混合良好。将BR-C12作为第三组分加入PM6:Y6中，BR-C12与PM6和Y6具有互补吸收，促进激子解离和电荷收集，减少双分子重组，导致分子堆积更加有序。与主机二进制设备 (16.42%) 相比，PM6:Y6:BR-C12（1:1.2:0.1，重量比）OSC 的功率转换效率 (PCE) 提高了 17.02%。此外，通过将BR-C12作为第三组分加入PM6:L8-BO中，基于PM6:L8-BO:BR-C12的三元器件也实现了器件光伏性能的显着提升，PCE为18.26%。此外，添加 BR-C12 的三元器件表现出比二元器件更高的稳定性。这项工作提出了一种构建高性能三元 OSC 的方法，并丰富了第三种成分的材料。