Highly fluorinated polyimide gate dielectric for fully transparent aqueous precursor derived In–Zn oxide thin-film transistors

The development of flexible dielectric polymers with robust temperature durability, excellent mechanical properties and high transparency will be of great significance for the soft electronics. In current work, a highly fluorinated polyimide (hF-PI) material was successfully synthesized. By using (3-Aminopropyl) triethoxysilane as “bridge” and controlling the humidity rigidly, transparent polyimide films with smooth surface and tight adhesion to a strong substrate was prepared. As well, the mechanism of non-transparent hF-PI film formation in an ambient atmosphere at a low concentration was clarified. Based on the high temperature resistance of the hF-PI, the indium–zinc oxide (IZO) semiconductor film was successfully prepared on hF-PI film by the simple eco-friendly aqueous route. The IZO thin-film transistor using hF-PI film as insulating layer exhibited highly transparent and excellent electrical performance in the carrier mobility and the on/off current ratio. In addition, the operating voltage was greatly reduced by physically doping with carbon nanotube, while the devices still maintained good transparency.