Crystalline polymer nanowires originating from solution-state aggregation for high-performance field-effect transistors

Abstract

The ordered stacking of polymer semiconductor molecular chains serves as a critical foundation for efficient charge-carrier transport. However, the inherent long-chain structure and entanglement behavior of polymer chains often pose significant challenges in achieving highly oriented molecular stacking structures. Herein, inspired by the inheritance of the polymer aggregate structure from solution to solid states, a facile method for the fabrication of crystalline nanowires based on diketopyrrolopyrrole-dithienyl-thieno[3,2-b]thiophene (DPP-DTT) has been proposed to realize high-performance organic field-effect transistors (OFETs). The morphology of the DPP-DTT films prepared with different solvents was first studied to investigate the influence of solvent on the pre-aggregation behavior of the DPP-DTT molecules. Based on the fibrous network structure of the DPP-DTT films obtained from a chloronaphthalene solution, crystalline nanowires were achieved by further controlling the processing temperature. The OFET based on these crystalline nanowires achieved a maximum mobility of 11.06 cm² V⁻¹ s⁻¹ and an average value of 6.02 cm² V⁻¹ s⁻¹, which is an order of magnitude higher than that of film-based devices. This work not only highlights a strategy for regulating molecular packing based on the inheritance of the aggregate structure from the solution to the solid state, but also advances the research on crystalline polymer nanowires and the development of corresponding high-performance devices.