IDTBT has been one of the most interesting , with respect to properties, e.g., great solubility and high charge carrier mobility , and puzzling, regarding the morphology-property relationships, SCPs of this kind. Therefore, the special structural features of this polymer has been extensively investigated . It is generally believed that the torsion-free backbone of polymer (due to the high torsion barrier between IDT and BT) results in a ribbon-like chain conformation and provides a great intrachain charge transport . However, there is a considerable degree of uncertainty in the reported characteristics of IDTBT microstructure.