Field-effect transistor based on the proton conductivity of graphene oxide and nafion films

Proton conductivity in graphene oxide and Nafion films depending on humidity and voltages across electrodes is studied in the model of a field-effect transistor. The electrical characteristics of the films are similar to one another, but the mobility of positive charges in Nafion and the current gain are higher by 2–3 orders of magnitude compared with graphene oxide. The negative ion current in graphene-oxide films at positive bias voltage is significant compared with the proton current (up to $\sim$10%), while it is almost lacking in Nafion films ($<$ 1%).