For instance, while several studies emphasise its amorphous-like structure , some reports a limited degree of crystallinity and there is also reported evidence of remarkable shortand medium-range order and unconventional packing (compared with conventional semicrystalline polymers) . Thus, the degree and nature of order (if exists) seems rather unclear. More importantly, there is no reported firm evidence about the origin of observed (limited degree of) molecular arrangements in this polymer. Furthermore, the charge transport mechanism in IDTBT is (generally) believed to be mainly one dimensional and through the backbone of polymer . This is mainly based on the lack or very limited amount of crystallinity as observed by DSC or GIWAXD for this polymer. However, it is believed that for the extraordinary high mobility of this polymer, a strong interchain electronic coupling is crucial .