Molecular ordering of high-performance soluble molecular semiconductors and re-evaluation of their field-effect transistor characteristics

An investigation of structural properties spin-coated thin films of soluble molecular semiconductors 2,7-dialkyl[1]benzothieno[3,2-b][1]benzothiophenes (C_n-BTBTs) is reported. C_n-BTBTs can be used as a high performance solution-processed organic semiconducting layers in organic field effect transistors (OFET) devices. The study also investigated the molecular ordering of these molecular semiconductors. X-ray diffraction (XRD) measurement of the thin films during the study revealed that the molecular patterns in the substrate are identical for all the compounds irrespective of alkyl chain length. The investigation concluded that these molecules with different intermolecular interactions can be used to prepare an ordered molecular arrays with large intermolecular overlaps.