Toward Chemical Logic with Electrolyte-Gated Graphene-based Transistors

Abstract

While the usual complementary inverter is composed of a pair of n-type and p-type field-effect transistors, we show that a functional inverter can be made out of p-doped reduced graphene oxide (rGO) transistors, operating in the electrolyte-gated configuration. We developed such devices on flexible polyimide substrates, from the deposition of a water-based home-made formulation of graphene oxide (GO). GO was furtherly turned into rGO by an in situ electroreduction step, able to tune the doping level of the material. We explored the experimental key parameters that control the electrical features of single rGO-transistors involved in the inverter, especially the interplay between gate and drain voltages and we developed a numerical toy-model in order to have a better understanding on the electric behavior of our ambipolar rGO-based inverters. Through the functionalization of the device's channel with a potassium ionophore III membrane, we show the proof of concept of an original rGO-based ion sensor able to detect a certain ion concentration threshold in aqueous media, with a direct numerical or voltage readout method, which is conforming to the emerging field of Chemical Logic, and that is less resources-consuming regarding the integration of such sensors in electronic circuits.