Electrochemical Doping of Graphene with H2SO4 Electrolyte

Because graphene has been studied for applications to both flexible and transparent electrodes, conductivity improvements by tuning the doping condition represent a significant strategy. Although electrolyte gating avenues for tuning the graphene doping condition are frequently utilized to realize a high carrier density in graphene, more information pertaining to the doping condition of graphene by electrolyte gating is continuously required. Here, variations of the doping of graphene with the application of electrolyte gate voltage are studied. In detail, upon employing an electrolyte gating, it is verified that the Fermi level can be tuned to more than 288 meV and that recovery to the initial doping condition typically requires more than 24 hours. Furthermore, this doping variation can be adjusted by applying positive and negative electrolyte gate voltages immediately.