Flexible alkyl side chain in conjugate polymers (CPs) improves the solubility and promotes solution processability, in addition, it affects interchain packing and charge mobilities. Despite the well-known charge mobility and morphology correlation for these semi-crystalline polymers, there is a lack of fundamental understanding of the impact of side chain on their crystallization kinetics. In the present work, isothermal crystallization of five poly(3-alkylthiophene-2,5-diyl) (P3ATs) with different side-chain structures were systematically investigated. To suppress the extremely fast crystallization and trap the sample into amorphous glass, an advanced fast scanning chip calorimetry technique, which is able to quench the sample with few to tens thousands of K/s, was applied. Results show that the crystallization of P3ATs was greatly inhibited after incorporation of branched side chains, as indicated by a dramatic up to six orders of magnitude decrease in the crystallization rate. The suppressed crystallization of P3ATs were correlated with an increased π–π stacking distance due to unfavorable side-chain steric interaction. This work provides a pathway to use side-chain engineering to control the crystallization behavior for CPs, thus to control device performance.

共轭聚合物（CP）中的柔性烷基侧链可提高溶解度并提高溶液的可加工性，此外，还会影响链间的堆积和电荷迁移率。尽管这些半结晶聚合物具有众所周知的电荷迁移率和形态相关性，但对侧链对其结晶动力学的影响尚缺乏基本的了解。在本工作中，系统研究了五个具有不同侧链结构的聚（3-烷基噻吩-2,5-二基）（P3ATs）的等温结晶。为了抑制极快的结晶并将样品捕获到非晶态玻璃中，应用了一种先进的快速扫描芯片量热技术，该技术能够以极少的几万K / s的速度淬灭样品。结果表明，支链侧链并入后，P3ATs的结晶受到了极大的抑制，这表明结晶速率下降了多达六个数量级。由于不利的侧链空间相互作用，P3ATs的结晶抑制与增加的π-π堆积距离有关。这项工作提供了使用侧链工程控制CP的结晶行为，从而控制器件性能的途径。