Three types of tail-to-tail (PDCBT_TT), head-to-tail (PDCBT_HT), and head-to-head (PDCBT_HH) regioisomeric polythiophene copolymers were synthesized by modification of the substitution positions of their alkoxycarbonyl side-chains. Chain conformation, and optical, electrochemical, morphological, and charge-transport characteristics of the polymers were significantly influenced by their regiochemistry. PDCBT_HH showed an amorphous morphology due to strong steric hindrance between its head-to-head alkoxycarbonyl side-chains, resulting in the poorest performance in organic solar cells and transistors among three types. PDCBT_HT had a regiorandom structure with both head-to-tail and tail-to-head linkages in a polymer chain. As determined by field-effect mobility measurements, a highly regioregular and planar PDCBT_TT exhibited the highest hole mobility (μ = 0.065 cm² V^-1s^-1), which was two orders of magnitude higher than that of the regiorandom PDCBT_HT. The highest photovoltaic performance was also measured for PDCBT_TT:a fullerene acceptor (PC₇₁BM), by maintaining the packed structures of pristine PDCBT^TT polymers in the blend with PC₇₁BM. Altering the topology of alkoxycarbonyl side-chains of the copolymers resulted in significant differences in crystalline morphologies and electrical properties and thus should be carefully considered in the molecular design of organic semiconductors.

中文翻译：

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区域异构聚噻吩衍生物：有机电子器件的合成与结构-性能关系

通过修饰烷氧基羰基侧链的取代位置，合成了三种尾对尾（PDCBT _TT），头对尾（PDCBT _HT）和头对头（PDCBT _HH）区域异构聚噻吩共聚物。 。聚合物的链构象，光学，电化学，形态和电荷传输特性都受到其区域化学的显着影响。由于PDCBT _HH的头对头烷氧羰基侧链之间存在强烈的空间位阻，因此其表现出无定形形态，导致有机太阳能电池和晶体管中三种类型的性能最差。PDCBT _HT具有在聚合物链中头到尾和尾到头的连接的区域随机结构。如通过场效应迁移率测量所确定的，具有高区域规则性和平面性的PDCBT _TT表现出最高的空穴迁移率（μ= 0.065 cm ² V ^-1 s ^-1），比区域随机性PDCBT _HT高两个数量级。通过保持与PC ₇₁共混的原始PDCBT ^TT聚合物的填充结构，还对PDCBT _TT：富勒烯受体（PC ₇₁ BM）测量了最高的光伏性能。BM。改变共聚物的烷氧羰基侧链的拓扑结构会导致晶体形态和电性能的显着差异，因此在有机半导体的分子设计中应谨慎考虑。