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

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 π-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 π-electrons were delocalized among the thiophene rings, thereby improving the interchain charge transport ability; the resulting planar π-electron system in PAT:ATP resulted in closer intermolecular π–π 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 × 10⁻⁴ cm² V⁻¹ s⁻¹ at −30 V and a threshold voltage (V_th) of 5 V, and an on/off current ratio of 10⁶. This method has great potential for inducing selective intermolecular interactions in fully solution processed electronic devices.