Large-Scale Patterning and Polymorph Transition of Conjugated Polymers via Meniscus-Guided Deposition for Field-Effect Transistors.

The ability to craft patterned conjugated polymers and simultaneously induce polymorph transitions within these patterns is important for various organic semiconductor devices. However, simple and straightforward routes to achieving both desirable characteristics remain a grand challenge. Herein, we report an effective meniscus-guided deposition (MGD) strategy to generate highly ordered, periodic microscopic patterns (i.e., dots and stripes) in poly(3-hexylselenophene) (P3HS) and enable a polymorph transition within these stripe arrays. Specifically, the P3HS solution is contained within the gap of two nearly parallel plates, and the MGD method renders the deposition of P3HS into large-scale, periodic patterns through a repetitive stop-and-move process of the meniscus. Dots and stripe arrays are crafted depending on the P3HS solution concentration. Interestingly, with the increased MGD speed, the transition from polymorph II to polymorph I was completed within the stripe arrays. The organic field-effect transistor performance pinpoints a significant relationship between different P3HS stripe arrays and their charge transport characteristics. The MGD strategy to efficiently produce P3HS patterns and induce polymorph transition is readily adaptable to other conjugated polymers for diverse optoelectronic applications.