A skeletal randomization strategy for high-performance quinoidal-aromatic polymers

• Published in: Materials horizons 2024-01, Vol.11 (1), p.283-296
• Main Authors: Zhou, Quanfeng, Liu, Cheng, Li, Jinlun, Xie, Runze, Zhang, Guoxiang, Ge, Xiang, Zhang, Zesheng, Zhang, Lianjie, Chen, Junwu, Gong, Xiu, Yang, Chen, Wang, Yuanyu, Liu, Yi, Liu, Xuncheng
• Format: Article
• Language: English
• Subjects: Charge transport; Commercialization; Crystallinity; Field effect transistors; Hole mobility; Homology; Polymers; Randomization; Semiconductor devices; Solubility; Thin films; Tuning
• ISSN: 2051-6347; 2051-6355
• DOI: 10.1039/d3mh01143g

Enhancing the solution-processability of conjugated polymers (CPs) without diminishing their thin-film crystallinity is crucial for optimizing charge transport in organic field-effect transistors (OFETs). However, this presents a classic "Goldilocks zone" dilemma, as conventional solubility-tuning methods for CPs typically yield an inverse correlation between solubility and crystallinity. To address this fundamental issue, a straightforward skeletal randomization strategy is implemented to construct a quinoid-donor conjugated polymer, PA4T-Ra , that contains para -azaquinodimethane ( p -AQM) and oligothiophenes as repeat units. A systematic study is conducted to contrast its properties against polymer homologues constructed following conventional solubility-tuning strategies. An unusually concurrent improvement of solubility and crystallinity is realized in the random polymer PA4T-Ra , which shows moderate polymer chain aggregation, the highest crystallinity and the least lattice disorder. Consequently, PA4T-Ra -based OFETs, fabricated under ambient air conditions, deliver an excellent hole mobility of 3.11 cm 2 V −1 s −1 , which is about 30 times higher than that of the other homologues and ranks among the highest for quinoidal CPs. These findings debunk the prevalent assumption that a random polymer backbone sequence results in decreased crystallinity. The considerable advantages of the skeletal randomization strategy illuminate new possibilities for the control of polymer aggregation and future design of high-performance CPs, potentially accelerating the development and commercialization of organic electronics. A simple and effective skeletal randomization strategy is proposed to finely tune solution-state aggregation towards simultaneously improving the solubility and crystallinity of conjugated polymers, leading to a markedly boosted hole mobility.