Diketopyrrolopyrrole-thiophene-methoxythiophene based random copolymers for organic field effect transistor applications
Diketopyrrolopyrrole-thiophene-methoxythiophene based random copolymers for organic field effect transistor applications
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DOI：
10.1016/j.orgel.2020.105986
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发表时间：
2020-12-01
影响因子：
3.2
通讯作者：
Michinobu, Tsuyoshi
中科院分区：
文献类型：
--
作者：
Otep, Sultan;Lin, Yu-Che;Michinobu, Tsuyoshi
将甲氧基取代的噻吩单元引入到基于二酮基吡咯并吡咯和四噻吩的共聚物中以产生无规共聚物。甲氧基基团的引入使所得共聚物的光学能隙变窄，这是由于增强的平面主链导致更有效的共轭。在25mol%的低负载率下，无规共聚物表现出与基于二酮基吡咯并吡咯和四噻吩的原始聚合物相当的类似于0.3cm（2）V-1 s（-1）的空穴迁移率。虽然增加聚合物中甲氧基取代噻吩的比例导致分子量降低，但可以得出结论，引入甲氧基取代噻吩使空穴迁移率从50mol%负载量的0.02 cm（2）V-1 s（-1）提高到100mol%负载量的0.07 cm（2）V-1 s（-1）。增强是由于形成的预聚集体具有更强的链间相互作用，增加骨干共面性，导致在边缘上占主导地位和双峰的边缘上/面对的分子堆积方向。添加四甲基碘化铵作为离子添加剂被证明不是一种有效的方法，用于改善含有甲氧基取代的噻吩的聚合物的性能，而原始聚合物显示出显着的改善的电荷传输性能。
Methoxy-substituted thiophene units were incorporated into a diketopyrrolopyrrole and quaterthiophene based copolymer to produce random copolymers. Inclusion of the methoxy group narrowed the optical energy gap of the resulting copolymers owing to the enhanced planar backbone that results in more effective conjugation. At a low loading ratio of 25mol% random copolymer exhibited a hole mobility of similar to 0.3 cm(2) V-1 s(-1) comparable to that of the diketopyrrolopyrrole and quaterthiophene based original polymer. Although increasing the methoxy-substituted thiophene ratio in the polymers resulted in decreased molecular weights, it was concluded that incorporation of the methoxy-substituted thiophenes enhanced the hole mobility from 0.02 cm(2) V-1 s(-1) for 50mol% loading to 0.07 cm(2) V-1 s(-1) for 100mol% loading. The enhancement was attributed to the formation of pre-aggregates with stronger interchain interactions with increasing backbone coplanarity, resulting in edge-on dominant and bimodal edge-on/face-on molecular packing orientations. The addition of tetramethylammonium iodide as an ionic additive proved not to be an effective method for improving the performance of polymers containing the methoxy-substituted thiophenes, whereas the original polymer displayed a noticeable improvement of the charge transport properties.