Thiacycle-fused benzo[1,2-b:4,5-b′]dithiophenes (BDTs): synthesis, packing, molecular orientation and semiconducting properties
Thiacycle-fused benzo[1,2-b:4,5-b′]dithiophenes (BDTs): synthesis, packing, molecular orientation and semiconducting properties
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DOI：
10.1039/c7tc05317g
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发表时间：
2018-04
影响因子：
6.4
通讯作者：
Chengyuan Wang;Hiroshi. Nakamura;Hiroyoshi Sugino;K. Takimiya
中科院分区：
文献类型：
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作者：
Chengyuan Wang;Hiroshi. Nakamura;Hiroyoshi Sugino;K. Takimiya
有机半导体的分子结构和堆积结构对有机场效应晶体管中载流子的迁移率起着至关重要的作用。本文系统地研究了苯并[1，2-B：4，5-B′]二噻吩（BDT）的硫杂环功能化，以调节BDT的堆积、分子取向和半导体性能。在设计的具有六元或五元硫杂环的BDT衍生物中，硫原子连接在α-、β-或α-和β-位置，其中六元硫杂环中具有β-硫原子的衍生物表现出类似于红稠环的“pitched”π堆积模式和基底上的边缘分子取向。另一方面，其他衍生物表现出不同的堆积结构，具有较小的分子间轨道重叠和末端取向。基于前一种分子的薄膜OFV具有比后者更高的迁移率，将薄膜状态下的输运性质与硫原子的位置和硫杂环的大小相关联，这表明了在噻吩并苯中开发高性能半导体材料的新的分子修饰策略。
The molecular and packing structures of organic semiconductors play crucial roles in determining their charge carrier mobilities in organic field-effect transistors (OFETs). In this article, a systematic study on the functionalization of benzo[1,2-b:4,5-b′]dithiophene (BDT) with thiacycles to tune the packing, molecular orientation and semiconducting properties is reported. Among the designed BDT derivatives with six- or five-membered thiacycles containing sulphur atoms connected at the α-, β- or both α- and β-positions, the derivatives with β-sulphur atoms in the six-membered thiacycle exhibited a rubrene-like “pitched” π-stacking pattern and edge-on molecular orientation on the substrate. On the other hand, other derivatives exhibited different packing structures with a smaller intermolecular orbital overlap and end-on orientation. The thin-film OFETs based on the former molecules exhibited higher mobility than the latter, correlating the transport properties in the thin-film state with the position of the sulphur atoms and size of the thiacycles, which suggests novel molecular modification strategies in thienoacenes for the development of high performance semiconducting materials.