Controlled doping of graphene by impurity charge compensation via a polarized ferroelectric polymer

A simple technique of doping graphene by manipulating the adsorbed impurity charges is presented. Using a field effect transistor configuration, controlled polarization of a ferroelectric polymer gate is used to compensate and neutralize charges of one type. The uncompensated charges of the opposite type then dope graphene. Both n- and p- type doping are possible by this method which is non-destructive and reversible. We observe a change in n-type dopant concentration of 8x10¹² cm^-2 and a change in electron mobility of 650%. The electron and hole mobility are inversely proportional to the impurity concentration as predicted by theory. Selective doping of graphene can be achieved using this method by patterning gate electrodes at strategic locations and programming them independently. Such charge control without introducing hard junctions therefore permits seamless integration of multiple devices on a continuous graphene film.