AbstractThe incorporation of a highly extended π-electron system into a polymer backbone is an effective strategy to develop high-performance donor–acceptor (D–A) polymers suitable for organic electronics because this strategy can facilitate a dense π-π stacking structure, leading to efficient carrier transport. With this in mind, we developed phenanthro[1,2-b:8,7-b′]dithiophene (PDT) because this new phenacene-type molecule has a highly crystalline nature, deep HOMO level, and high hole mobility, which are characteristics known to be suitable for a donor unit in high-performance D–A polymers. In this focus review, we report recent progress in PDT-containing D-A polymers combined with various strong acceptor units. Incorporation of PDT into a polymer backbone results in deep HOMO energy levels of −5.4~−5.5 eV, strong aggregation, and a dense packing structure with a short π-stacking distance of 3.5~3.6 Å. PDT-based polymers with appropriate alkyl side chains exhibit high hole mobilities of up to 0.18 cm2 V−1 s−1 in organic field-effect transistor (OFET) devices due to their tendency to form highly ordered edge-on structures. Furthermore, we can adjust their level of molecular orientation from edge-on to face-on by increasing their molecular weight, leading to a high power conversion efficiency of over 6% in polymer solar cell (PSC) applications. These results demonstrate that PDT is a good candidate as a high-performance building block in D-A polymers.A recent progress of phenanthro[1,2-b:8,7-b′]dithiophene (PDT)-based low bandgap semiconducting polymers combined with various strong acceptor units are described. By incorporating a highly π-extended PDT core into the polymer backbone, the synthesized polymers have deep HOMO energy levels and formed a dense packing structure with a short π-stacking distance. The PDT-based polymers with optimal side chains and high molecular weight exhibit high hole mobility of up to 0.18 cm−1 V−1 s−1 in organic field-effect transistors and high power conversion efficiency over 6%. These results indicate that PDT is a good π-framework as high-performance semiconducting polymers.

中文翻译：

---

用于晶体管和太阳能电池应用的基于含硫非并苯型分子的低带隙半导体聚合物

摘要将高度扩展的 π 电子系统并入聚合物主链是开发适用于有机电子学的高性能供体-受体 (D-A) 聚合物的有效策略，因为该策略可以促进密集的 π-π 堆叠结构，导致到高效的承运人运输。考虑到这一点，我们开发了菲 [1,2-b:8,7-b'] 二噻吩 (PDT)，因为这种新的非苯​​型分子具有高度结晶性、深 HOMO 能级和高空穴迁移率，这些都是已知适用于高性能 D-A 聚合物中的供体单元的特性。在这次重点审查中，我们报告了含有 PDT 的 DA 聚合物与各种强受体单元相结合的最新进展。将 PDT 结合到聚合物主链中导致 -5.4~-5.5 eV 的深 HOMO 能级，强聚集，以及具有 3.5~3.6 Å 短 π 堆积距离的致密堆积结构。具有适当烷基侧链的基​​于 PDT 的聚合物在有机场效应晶体管 (OFET) 器件中表现出高达 0.18 cm2 V-1 s-1 的高空穴迁移率，因为它们倾向于形成高度有序的边缘结构。此外，我们可以通过增加它们的分子量来调整它们的分子取向水平，从边缘到正面，从而在聚合物太阳能电池 (PSC) 应用中实现超过 6% 的高功率转换效率。这些结果表明，PDT 是 DA 聚合物中高性能结构单元的良好候选者。菲 [1,2-b:8,7-b'] 二噻吩 (PDT) 基低带隙半导体聚合物的最新进展描述了各种强受体单元。通过将高度 π 扩展的 PDT 核结合到聚合物主链中，合成的聚合物具有较深的 HOMO 能级，并形成了具有较短 π 堆积距离的致密堆积结构。具有最佳侧链和高分子量的基于 PDT 的聚合物在有机场效应晶体管中表现出高达 0.18 cm-1 V-1 s-1 的高空穴迁移率和超过 6% 的高功率转换效率。这些结果表明，PDT 是作为高性能半导体聚合物的良好 π 框架。