LAUSR

Due to the highly directional nature of transport in polymer-based organic field-effect transistors (OFETs), alignment of the polymer backbone can significantly affect device performance. While many methods of alignment have been detailed, the mechanism of alignment is rarely revealed—especially in cases of flow-induced alignment. Polymer aggregates are often observed in highly aligned systems, but their role is similarly unclear. Here, we present a comprehensive characterization of blade-coated P(NDI2OD-T2) (N2200) for OFET applications, including a rigorous, multimodal characterization of its in-plane alignment. Film thickness follows the expected power-law dependence on coating speed, while bulk polymer backbone orientation transitions from perpendicular to parallel to the coating direction as speed is increased. Charge carrier mobility >2 cm2/(V s) is achieved parallel to the coating direction for aligned N2200 coated at 5 mm/s and is found to be strongly correlated with the in-plane alignment of the ...