A liquid-crystalline semiconducting polymer based on thienylene-vinylene-thienylene: Enhanced hole mobilities by mesomorphic molecular ordering and thermoplastic shape-deformable characteristics
A liquid-crystalline semiconducting polymer based on thienylene-vinylene-thienylene: Enhanced hole mobilities by mesomorphic molecular ordering and thermoplastic shape-deformable characteristics
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DOI：
10.1038/s41428-019-0282-4
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发表时间：
2020-03-01
期刊：
影响因子：
2.8
通讯作者：
Yasuda, Takuma
中科院分区：
文献类型：
--
作者：
Mori, Tatsuya;Komiyama, Hideaki;Yasuda, Takuma
液晶(LC)聚酰亚胺共轭聚合物是一类新兴的半导体材料，因其在有机场效应晶体管(OFET)中具有良好的性能而受到人们的关注。然而，人们对LC性质和载流子迁移率之间的关系知之甚少。本文以一种含有亚硫烯-亚乙撑-亚硫烯(TVT)单元的噻吩基p型半导体聚合物PC12TV12T为研究对象，系统地研究了其热致液晶特性、体相和薄膜中的自组织结构以及场效应管中的电荷输运特性。我们发现，在LC温度(99-170℃)下的热退火显著地提高了OFET的性能，导致场效应空穴迁移率高达0.37 cm(2)V~(-1)S(-1)，与非晶硅相当。由于其热塑性，这种基于TVT的聚合物还可以加工成精细的半导体微纤维，甚至可以作为p型电荷传输的有源通道。这种自下而上的技术利用了液晶的性质，使得光电子器件的制造具有成本效益和能源效率。基于亚硫烯-亚乙烯-亚硫烯(TVT)单元的聚酰亚胺共轭聚合物可以在很宽的温度范围内形成热致液晶(LC)中间相。由于分子有序性的改善，LC温度下的热退火大大提高了有机场效应晶体管(OFET)的空穴迁移率。由于其热塑性，基于TVT的聚酰亚胺共轭聚合物还可以加工成半导体微细纤维，并作为微纤维OFET中的电荷传输路径。
Liquid-crystalline (LC) pi-conjugated polymers are an emerging class of semiconducting materials owing to their promising performance in organic field-effect transistors (OFETs). Little is known, however, about the relationship between LC nature and charge carrier mobility. In this paper, we focus on a thiophene-based p-type semiconducting polymer, PC12TV12T, containing thienylene-vinylene-thienylene (TVT) units, and report a systematic investigation of its thermotropic LC properties, self-organized structures in bulk and thin films, as well as charge transport properties in OFETs. We found that thermal annealing at LC temperatures (99-170 degrees C) strongly enhanced OFET performance, leading to field-effect hole mobilities as high as 0.37 cm(2) V-1 s(-1), comparable to that of amorphous silicon. By virtue of its thermoplasticity, the TVT-based polymer can also be processed into fine semiconducting microfibers, which can even function as a p-type active channel for charge transport. This bottom-up technology utilizing the LC nature enables cost-effective and energy-efficient manufacture of optoelectronic devices.A pi-conjugated polymer based on thienylene-vinylene-thienylene (TVT) units can form a thermotropic liquid-crystalline (LC) mesophase over a wide temperature range. Thermal annealing at LC temperatures strongly enhanced hole mobilities in organic field-effect transistors (OFETs) owing to improved molecular ordering. Because of its thermoplasticity, the TVT-based pi-conjugated polymer can also be processed into semiconducting fine microfibers and serve as a charge transport pathway in microfiber OFETs.