The transfer doping of graphite and graphene

It has been commonly thought that diamond is unique in its class in that it can undergo p-type transfer doping when covered by a thin layer of electrolyte. In this study, density- functional theory has been used to show that the work functions of graphite and graphene are low enough for transfer doping to occur between a graphite or graphene substrate and an aqueous adsorbate layer. The possible electrochemical reactions are the same as those favoured in the case of diamond, e.g. O-2, +2H(2)O + 4e(-) -> 4OH(-), where the electrons have been provided by the graphite or graphene substrate. Notably, the extraordinary nature of carrier transport in (single-layer) graphene renders this non-disruptive doping method an exciting possibility. (C) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.