Water-Borne Fluorinated\nPolyimide Dielectric for Large-Area\nIGZO Transistors and Logic Gates

Thin-film transistors offer excellent and uniform electrical\nproperties\nover large areas, making them a promising option for various future\nelectronic devices. Polyimide dielectrics are already widely used\nin various electronic devices because of their exceptional dielectric\nproperties, thermal stability, and desirable mechanical flexibility,\nwhich make them suitable for harsh environments. However, the current\nresearch on polyimide dielectric materials has certain limitations,\nsuch as the use of toxic solvents, high-temperature processes, and\ndeficient coating properties. Herein, we introduce an aromatic polyimide\ndielectric, which exhibits excellent electrical properties even when\nprocessed at a low temperature of 250 °C using environmentally\nfriendly water-based “one-step” polymerization. Despite\nits thin thickness of <200 nm, the water-borne fluorinated polyimide\ndielectric material demonstrates stable insulating properties over\na wide range of electric fields and achieves a high breakdown voltage\nof over 4.5 MV cm<sup>–1</sup>. Furthermore, we successfully\nachieved a large-area coating of uniform dielectric layers with no\npinholes using only water as a solvent and a simple solution process\nwithout any additional processing steps. These results demonstrate\nthat the water-borne polyimide gated indium–gallium–zinc\noxide transistor exhibits excellent and stable device performance.\nMoreover, we used the transistor to successfully demonstrate various\nlogic gates (NOT, NAND, and NOR). Overall, this study provides guidelines\nfor the eco-friendly and sustainable use of water-borne polyimide\ndielectric materials with high electrical performance and large-processing\nwindow advantages.