Molecular Ordering of High‐Performance Soluble Molecular Semiconductors and Re‐evaluation of Their Field‐Effect Transistor Characteristics

Intermolecular hydrophobic interactions between long alkyl chains (fastener effect) can enhance the intermolecular overlap of the semiconducting layer of 2,7-dialkyl[1]benzothieno[3,2-b][1]benzothiophenes (Cn-BTBTs; n = 8, 10, 12), which contributes to improvements of the electric characteristics of their organic field-effect transistors. The molecular ordering of Cn-BTBTs in the thin-film state is elucidated by means of in-plane and out-of-plane X-ray diffraction of spin-coated thin films, and single crystal X-ray analysis.