Department of Materials Science and Engineering and The Shenzhen Key Laboratory for Printed Organic Electronics, South University of Science and Technology of China, No. 1088, Xueyuan Road, Shenzhen, Guangdong, 518055, China.
Department of Chemistry, Wuhan University, Wuhan, Hubei, 430072, China.
Angew Chem Int Ed Engl. 2017 Nov 27;56(48):15304-15308. doi: 10.1002/anie.201708421. Epub 2017 Nov 3.
Two new bithiophene imide (BTI)-based n-type polymers were synthesized. f-BTI2-FT based on a fused BTI dimer showed a smaller band gap, a lower LUMO, and higher crystallinity than s-BTI2-FT containing a BTI dimer connected through a single bond. s-BTI2-FT exhibited a remarkable electron mobility of 0.82 cm V s , and f-BTI2-FT showed a further improved mobility of 1.13 cm V s in transistors. When blended with the polymer donor PTB7-Th, f-BTI2-FT-based all-polymer solar cells (all-PSCs) attained a PCE of 6.85 %, the highest value for an all-PSC not based on naphthalene (or perylene) diimide polymer acceptors. However, s-BTI2-FT all-PSCs showed nearly no photovoltaic effect. The results demonstrate that f-BTI2-FT is one of most promising n-type polymers and that ring fusion offers an effective approach for designing polymers with improved electrical properties.
两种新型的噻吩并[3,2-b]噻吩二酰亚胺（BTI）基的 n 型聚合物被合成了。基于稠合 BTI 二聚体的 f-BTI2-FT 表现出比含有通过单键连接的 BTI 二聚体的 s-BTI2-FT 更小的带隙、更低的 LUMO 和更高的结晶度。s-BTI2-FT 表现出显著的电子迁移率为 0.82 cm V s ，而 f-BTI2-FT 在晶体管中表现出进一步提高的迁移率为 1.13 cm V s。当与聚合物给体 PTB7-Th 共混时，基于 f-BTI2-FT 的全聚合物太阳能电池（all-PSCs）获得了 6.85%的光电转换效率（PCE），这是不基于萘（或苝）二酰亚胺聚合物受体的全-PSC 的最高值。然而，s-BTI2-FT 的全-PSC 几乎没有光伏效应。结果表明，f-BTI2-FT 是最有前途的 n 型聚合物之一，并且环稠合提供了一种设计具有改善的电性能的聚合物的有效方法。
