Supramolecular control over the morphology of bio-inspired poly(3-hexylthiophene) for organic thin film transistors

Abstract

We have developed a strategy for modifying the channel layer of organic thin film transistors (OTFTs) through side-chain induced self-organization into a well-ordered film. To obtain selectively self-patterned layers, we treated an adenine-functionalized poly(3-hexylthiophene) (PAT) with adenosine triphosphate (ATP). Using this strategy, interchain charge transport resulting from pi-conjugation was selected to control the polymer morphology, without the need of additional chemical synthetic processing. The side chain-induced self-organization can be understood in terms of supramolecular interactions. The pi-electrons were delocalized among the thiophene rings, thereby improving the interchain charge transport ability; the resulting planar pi-electron system in PAT: ATP resulted in closer intermolecular pep distances, facilitating enhanced charge carrier mobility within a fibrillar structure. The PAT: ATP-based OTFT device exhibited moderate to improved electronic characteristics, with an average field mobility of 3.2 x 10(-4) cm(2) V-1 s(-1) at -30 V and a threshold voltage (V-th) of 5 V, and an on/off current ratio of 10(6). This method has great potential for inducing selective intermolecular interactions in fully solution processed electronic devices. (C) 2016 Elsevier B.V. All rights reserved.