Development of High Capacitance Gate Dielectrics for Flexible Oxide Thin-Film Transistors Using Ionic Liquid-Polymer Materials

Abstract

Flexible and high capacitance dielectric materials have been widely studied to achieve high performance flexible electronic devices. Especially, high capacitance flexible gate insulator materials have been spotlighted for developing low voltage operated flexible thin-film transistors (TFTs). In development of flexible TFTs, solution processes are attractive methods for low-cost and large-area fabrication. However, conventional solution-processed flexible TFTs have limitations and obstacles, such as a high operating voltage, a high annealing temperature and a decrease of charge carrier mobility. Therefore, many research groups have tried to improve the limitations by developing high capacitance dielectric layers for low voltage operated solution-processed flexible TFTs. Herein, I have developed high capacitance flexible dielectric materials using combination of ionic liquid-polymers for developing high performance gate insulator by simple solution process. The ionic liquid-polymer dielectric materials are studied with cross-linked polymer and self-healing polymer for developing high performance flexible gate insulator. Due to the high ion mobility of ionic liquid, ionic liquid-polymer dielectric layers showed high capacitance values. In addition, the ionic liquid-polymer dielectric layers exhibited own unique characteristics according to the properties of each polymer. As results, ionic liquid-polymer dielectric materials showed both high capacitance value and flexibility and well operated flexible oxide TFTs at low operating voltages.