Three wide-band-gap donor–acceptor (D–A) type polymers, PBA-TX, PBA-T2, PBA-T3, and PBA-T4, based on alkoxy-substituted anthrabisthiadiazole (ATz) and benzodithiophene (BDT) structures, were synthesized and characterized for the development of high-performance semiconducting polymers in non-fullerene organic photovoltaics (OPVs). The synthesized polymers PBA-TX possess deep highest occupied molecular orbital (HOMO) energy levels of −5.4–5.5 eV and a relatively wide band gap of 1.8 eV, attributed to the introduction of the alkoxy-substituted ATz core with a weak electron-acceptor character into polymer backbones. Additionally, the bulky alkylthienyl side chains on the BDT core provide sufficient solubility and suppress the formation of lamellar structures, enabling the construction of a suitable face-on orientation in the solid state and high miscibility with representative low-band-gap small-molecular acceptor (SMA) Y6. The halogenation of the β-position of alkylthienyl groups on the BDT core further reduced the HOMO and lowest unoccupied molecular orbital (LUMO) energy levels. Solar cells fabricated with halogen atom-substituted polymers PBA-T3 (chlorine) and PBA-T4 (fluorine) exhibited a higher open-circuit voltage (V_oc) than cells based on the nonhalogenated polymer PBA-T2. Interestingly, all PBA-TX/Y6 blended films formed almost the same molecular order and phase separation structures. As a result, all fabricated solar cells based on PBA-TX/Y6 systems showed a similar power conversion efficiency (PCE) of around 8–9%. One possible reason for the small differences observed may be attributed to the presence of an ATz framework in the polymer backbone, as its rigid and π-extended manner can provide sufficient strong intermolecular interaction. The subtle halogenation effect here proves advantageous for crafting halogen-free wide-band-gap semiconducting polymers in non-fullerene organic photovoltaics (OPVs), steering clear of intricate synthetic pathways.

中文翻译：

---

用于高性能非富勒烯太阳能电池的烷氧基取代蒽并噻二唑-苯并二噻吩基宽带隙半导体聚合物

三种宽带隙供体-受体（D-A）型聚合物，PBA-TX、PBA-T2、PBA-T3和PBA-T4，基于烷氧基取代的蒽并噻二唑（ATz）和苯并二噻吩（BDT）结构，的合成和表征用于非富勒烯有机光伏（OPV）中高性能半导体聚合物的开发。合成的聚合物PBA-TX具有-5.4-5.5 eV的深最高占据分子轨道（HOMO）能级和1.8 eV的相对较宽的带隙，这归因于引入了具有弱电子受体的烷氧基取代的ATz核特征进入聚合物主链。此外，BDT核上的大烷基噻吩基侧链提供了足够的溶解度并抑制层状结构的形成，从而能够在固态下构建合适的正面取向，并与代表性的低带隙小分子受体具有高混溶性(SMA) Y6。 BDT 核上烷基噻吩基 β 位的卤化进一步降低了 HOMO 和最低未占分子轨道 (LUMO) 能级。用卤素原子取代的聚合物PBA-T3（氯）和PBA-T4 （氟）制造的太阳能电池表现出比基于非卤化聚合物PBA-T2的电池更高的开路电压（V _oc ） 。有趣的是，所有PBA-TX / Y6共混薄膜形成几乎相同的分子有序和相分离结构。因此，所有基于PBA-TX / Y6系统制造的太阳能电池都显示出类似的功率转换效率 (PCE)，约为 8-9%。观察到的微小差异的一个可能原因可能是由于聚合物主链中存在 ATz 骨架，因为其刚性和 π 延伸方式可以提供足够强的分子间相互作用。事实证明，这种微妙的卤化效应对于在非富勒烯有机光伏（OPV）中制造无卤宽带隙半导体聚合物是有利的，从而避开了复杂的合成途径。