Li Hongxiang, Liu Xinyu, Jin Tianya, Zhao Kefeng, Zhang Qiang, He Chunyong, Yang Hua, Chen Yu, Huang Jianyao, Yu Xinhong, Han Yanchun
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China.
Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
Macromol Rapid Commun. 2022 Aug;43(16):e2200084. doi: 10.1002/marc.202200084. Epub 2022 Apr 14.
The charge carrier transport of conjugated polymer thin film is mainly decided by the crystalline domain and intercrystallite connection. High-density tie-chain can provide an effective bridge between crystalline domains. Herein, the tie-chain connection behavior is optimized by decreasing the crystal region length (l ) and increasing the crystallization rate. Poly[4-(4,4-bis(2-octyldodecyl)-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-alt-[1,2,5]-thiadiazolo[3,4-c]pyridine] (PCDTPT-ODD) is dissolved in nonpolar solvent isooctane and high ordered rod-like aggregations are formed. As the temperature increases, the changes in solution state and crystallization behavior lead to three different chain arrangement morphologies in the films: 1) at 25 °C, large and separated crystal regions are formed; 2) at 55 °C, small and well-connected crystal regions are formed due to faster crystallization rate and smaller nucleus size; 3) at 90 °C, the amorphous film is formed. Further results show that the film prepared at 55 °C has a smaller crystal region length (l , 7.6 nm) and higher tie-chains content. Thus, the film exhibits the best device mobility of 2.3 × 10 cm V s . This result shows the great influence of crystallization kinetics on the microstructure of conjugated polymer films and provides an effective way for the optimization of the intercrystallite tie-chain.
共轭聚合物薄膜中的载流子传输主要由结晶区域和晶粒间连接决定。高密度的连接链可以在结晶区域之间提供有效的桥梁。在此，通过减小晶体区域长度（l）和提高结晶速率来优化连接链的连接行为。将聚[4-(4,4-双(2-辛基十二烷基)-4H-环戊并[1,2-b:5,4-b']二噻吩-2-基)-alt-[1,2,5]-噻二唑并[3,4-c]吡啶]（PCDTPT-ODD）溶解在非极性溶剂异辛烷中，形成高度有序的棒状聚集体。随着温度升高，溶液状态和结晶行为的变化导致薄膜中出现三种不同的链排列形态：1）在25℃时，形成大的且分离的结晶区域；2）在55℃时，由于结晶速率更快且核尺寸更小，形成小的且连接良好的结晶区域；3）在90℃时，形成非晶薄膜。进一步的结果表明，在55℃制备的薄膜具有更小的晶体区域长度（l，7.6nm）和更高的连接链含量。因此，该薄膜表现出最佳的器件迁移率，为2.3×10 cm V s 。这一结果表明了结晶动力学对共轭聚合物薄膜微观结构的重大影响，并为优化晶粒间连接链提供了一种有效方法。
