Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
Nat Commun. 2013;4:2238. doi: 10.1038/ncomms3238.
One of the most inspiring and puzzling developments in the organic electronics community in the last few years has been the emergence of solution-processable semiconducting polymers that lack significant long-range order but outperform the best, high-mobility, ordered semiconducting polymers to date. Here we provide new insights into the charge-transport mechanism in semiconducting polymers and offer new molecular design guidelines by examining a state-of-the-art indacenodithiophene-benzothiadiazole copolymer having field-effect mobility of up to 3.6 cm(2) V(-1) s(-1) with a combination of diffraction and polarizing spectroscopic techniques. Our results reveal that its conjugated planes exhibit a common, comprehensive orientation in both the non-crystalline regions and the ordered crystallites, which is likely to originate from its superior backbone rigidity. We argue that charge transport in high-mobility semiconducting polymers is quasi one-dimensional, that is, predominantly occurring along the backbone, and requires only occasional intermolecular hopping through short π-stacking bridges.
在过去几年中，有机电子学领域最令人振奋和困惑的发展之一是出现了可溶液处理的半导体聚合物，这些聚合物缺乏明显的长程有序性，但性能优于迄今为止最好的、具有高迁移率的有序半导体聚合物。在这里，我们通过结合衍射和偏振光谱技术，研究了一款具有高达 3.6 cm(2) V(-1) s(-1) 的场效应迁移率的最先进的茚并二噻吩-苯并噻二唑共聚物，为半导体聚合物中的电荷输运机制提供了新的见解，并提供了新的分子设计指南。我们的结果表明，其共轭平面在非晶区和有序晶区都表现出共同的、全面的取向，这可能源于其优异的主链刚性。我们认为，在高迁移率半导体聚合物中，电荷输运是准一维的，即主要沿主链发生，并且仅需要通过短的π-堆叠桥偶尔进行分子间跳跃。
