Highly-ordered Triptycene Modifier Layer Based on Blade Coating for Ultraflexible Organic Transistors

We present a highly ordered surface modification layer for polymers based on ambient solution-processed triptycene (Trip) derivatives for high-mobility organic thin-film transistors (OTFTs). The nested packing of Trip molecules results in the formation of 2D hexagonal arrays, which stack one-dimensionally on the surface of polymer dielectrics without anchoring groups. The Trip surface was previously shown to be preferable for the growth of organic semiconductors (OSCs), and hence for enhancing the mobility of OTFTs. However, although the Trip modifier layer has been realized by thermal evaporation in a high-vacuum environment (TVE), it still has grain-boundary disorders that hinder the optimal growth of OSCs. To fabricate OTFTs with higher mobility, a disorder-free Trip layer is needed. We developed highly ordered Trip layers on polymer dielectrics via blade coating. In addition, we clarified that the highly ordered Trip modifier layer enhances the mobility of the OTFTs by more than 40%, relative to the disordered Trip layer prepared by TVE. Finally, we realized a ring oscillator composed of OTFTs with a highly ordered Trip layer.