Water‐Surface‐Mediated Precise Patterning of Organic Single‐Crystalline Films via Double‐Blade Coating for High‐Performance Organic Transistors

Abstract Application‐oriented growth of patterned organic semiconductor (OSC) thin films with a single domain is a nonnegotiable requirement for the manufacturing of high‐performance organic electronic devices. However, the prevalent selective‐wetting patterning method remains a challenge in controlling the density of nucleation events in microscale spaces, resulting in thin films with high grain boundary density and no preferential orientation spherulites. Herein, a simple double‐blade‐coating printing technique using a combination of wetting‐patterned substrates to produce an array of highly crystalline OSC thin films is developed. Specifically, the approach confines the OSC crystallization on a molecular‐flat water surface in specific areas, enabling a significant reduction in the number of nuclei. Consequently, patterned 2,7‐dioctyl[1]benzothieno[3,2‐b] benzothiophene (C 8 ‐BTBT) thin films comprising single‐crystal domains are achieved with an exceptionally high yield of 62.5%. The organic field‐effect transistor array developed from such patterns of C 8 ‐BTBT single‐crystalline films exhibits an excellent average mobility of 11.5 cm 2 V −1 s −1 which is 12.5‐fold higher compared to that of the reference sample fabricated via conventional single‐blade coating. It is believed that this approach can be widely applied to other soluble organic materials, thereby opening up opportunities for fabricating multicomponent integrated electronics.