Large-Scale Patterning\nand Polymorph Transition of\nConjugated Polymers via Meniscus-Guided Deposition for Field-Effect\nTransistors

The ability to craft patterned conjugated polymers and\nsimultaneously\ninduce polymorph transitions within these patterns is important for\nvarious organic semiconductor devices. However, simple and straightforward\nroutes to achieving both desirable characteristics remain a grand\nchallenge. Herein, we report an effective meniscus-guided deposition\n(MGD) strategy to generate highly ordered, periodic microscopic patterns\n(i.e., dots and stripes) in poly(3-hexylselenophene) (P3HS) and enable\na polymorph transition within these stripe arrays. Specifically, the\nP3HS solution is contained within the gap of two nearly parallel plates,\nand the MGD method renders the deposition of P3HS into large-scale,\nperiodic patterns through a repetitive stop-and-move process of the\nmeniscus. Dots and stripe arrays are crafted depending on the P3HS\nsolution concentration. Interestingly, with the increased MGD speed,\nthe transition from polymorph II to polymorph I was completed within\nthe stripe arrays. The organic field-effect transistor performance\npinpoints a significant relationship between different P3HS stripe\narrays and their charge transport characteristics. The MGD strategy\nto efficiently produce P3HS patterns and induce polymorph transition\nis readily adaptable to other conjugated polymers for diverse optoelectronic\napplications.