High efficiency organic solar cells with great stability are crucial for future commercialization. Herein, a simple electron-donating monomer 2,6-dibromo-4,8-bis(octyloxy)benzo[1,2-b:4,5-b'] dithiophene (BDT-O) was synthesized as the third component to be introduced into the D-A backbone of PM6 by D-A non-equivalent random copolymerization. A series of wide-bandgap D-A-D-D₁-type random terpolymer donors PM6-Ox (x = 5, 10, 30) were obtained, in which BDT-O served as the third component D₁, fluorinated bis-2-ethylhexyl thiophene substituted benzodithiophene served as the D component and the typical 1,3-bis(4-(2-ethylhexyl) thiophen-2-yl)-5,7-bis(2-alkyl) benzo[1,2-c:4,5-c']dithiophene-4,8-dione was used as the A component. Morphological and photoelectronic characterizations are investigated to reveal the effects of BDT-O unit on the photovoltaic (PV) performances of polymers. Small content of BDT-O unit introduced into PM6 can effectively tune the absorption, energy levels and molecular arrangement of polymers for better solar light-harvesting and enhanced charge transport. By fabricating organic solar cells (OSCs) with the common acceptor Y6, the PM6-O5:Y6-based device achieved a much higher PCE of 17.65% than that of the reference PM6:Y6-based device. Besides, PM6-O5:Y6-based devices exhibit high thermal- and storage-stability, as well as outstanding photo-stability. This work will provide valuable clues on the molecular design of high-efficiency polymer donors via D-A non-equivalent random copolymerization strategy by incorporating a simple D₁ component.

具有高稳定性的高效有机太阳能电池对于未来的商业化至关重要。在此，合成了一种简单的供电子单体 2,6-二溴-4,8-​​双（辛氧基）苯并 [1,2- b :4,5- b' ] 二噻吩 (BDT-O) 作为第三种成分，通过 DA 非等价无规共聚引入到 PM6 的 DA 骨架中。得到了一系列宽带隙DADD ₁型无规三元共聚物供体PM6-Ox (x = 5, 10, 30)，其中BDT-O作为第三组分D 1 ，氟化双-2-乙基己基噻吩取代_苯并二噻吩作为D组分和典型的1,3-双（4-（2-乙基己基）噻吩-2-基）-5,7-双（2-烷基）苯并[1,2- c :4,5- C']dithiophene-4,8-​​dione 用作 A 组分。研究了形态学和光电表征，以揭示 BDT-O 单元对聚合物光伏 (PV) 性能的影响。在 PM6 中引入少量 BDT-O 单元可以有效地调节聚合物的吸收、能级和分子排列，从而更好地收集太阳光并增强电荷传输。通过使用共同受体 Y6 制造有机太阳能电池 (OSC)，基于 PM6-O5:Y6 的器件实现了比基于参考 PM6:Y6 的器件高得多的 PCE，达到 17.65%。此外，基于 PM6-O5:Y6 的器件具有很高的热稳定性和储存稳定性，以及出色的光稳定性。_1个组件。