A Physicochemical Approach Toward Extending Conjugation and the Ordering of Solution-Processable Semiconducting Polymers

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• 作者：Minjung Lee ; Hyeonyeol Jeon ; Mi Jang ; Hoichang Yang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：February 24, 2016
• 年：2016
• 卷：8
• 期：7
• 页码：4819-4827
• 全文大小：633K
• ISSN：1944-8252

文摘

Poly(3-hexylthiophene)s (P3HTs) were synthesized with a well-controlled molecular weight (Mw) and degree of regioregularity; additionally, π-conjugated P3HT structures in both solutions and films were systematically investigated. Conjugated P3HT phases in spin-cast films significantly changed from ordered nanorods, -fibrils, and -ribbons to less-ordered granules, depending on the conformation of the P3HT chains in solutions. The chain conformations could be physicochemically adjusted by modifying chain lengths (from 5 to 45 kDa), solvents, and ultrasonication. Highly extended conformations of the P3HT in ultrasound-treated solutions yielded longer degree of conjugation both the intra- and intermolecularly. When toluene was used as a marginal solvent, ultrasonicated 0.1 wt % 29 kDa P3HT solutions could be used to yield highly ordered aggregates in spin-cast films, including nanoribbons or nanosheets, with field-effect mobility (μ_FET) up to ∼0.1 cm² V^–1 s^–1 being measured for organic field-effect transistors (OFETs). However, ultrasonicated chloroform systems with good P3HT solubility (for P3HT Mw ≥ 20 kDa) yielded featureless conducting layers even at 0.4 wt % P3HT content. However, these film-based OFETs yielded μ_FET values up to 0.04 cm² V^–1 s^–1, which were much greater than 0.004 cm² V^–1 s^–1 for the nonultrasonicated systems.