Electric field gating with ionic liquids

Abstract

The authors show that ionic liquids are well suited to specialized electric field gating applications in which large surface charge densities can be induced on the surfaces of low-carrier density thin-film metals. Using either coplanar or overlay gate configurations, they demonstrate field-induced resistance changes on the order of a factor of 10 4 for thin conducting In O x films. The areal capacitances and field effect mobilities noticeably exceed those that can be achieved using Al O x dielectrics. In addition, the charge state can be frozen in by reducing the temperature, thus providing an opportunity for electric field tuning of metal-insulator transitions in a variety of thin-film systems.