Fluorinated polymeric insulating layer surface advancement by fluorine based cross-linking for high-performance organic electronic applications†

Abstract

Insulating polymeric layers, like fluorinated polymers, are excellent dielectric materials for organic field-effect transistors (OFETs). However, their high hydrophobicity hinders the deposition of crystalline organic semiconductors, and the poor interface formed deteriorates the charge transfer characteristics. To improve the interface between the dielectric and organic semiconductor, the hydrophobicity of the polymer dielectric must be slightly reduced. Herein, we report the surface tuning of fluorinated dielectrics by the incorporation of fluorine-based UV-assisted crosslinkers. Because the crosslinker is also fluorine-based, the dielectric polymer solution can be homogenously mixed and deposited by a facile printing process to produce a highly polymerized film with excellent insulating properties. Characterization results confirm that the dielectric with crosslinkers enables the formation of an organic semiconductor layer with large crystal grains that facilitates charge transfer at the interface. As the characterization results, transfer curves, and bias-stress test results revealed, the high-quality interface enabled the successful fabrication of OFETs with excellent electrical performance and high thermal stability. The printing process was then applied to integrate multiple n-type and p-type OFETs into NOT, NOR, and NAND gates, demonstrating that the surface modulation of organic dielectrics is scalable and effective in fabricating stable and high-performance large-area organic field-effect devices.