Transport properties of pristine and doped graphene

Graphene has attracted a lot of attention for various applications recently. Chemically exfoliated graphene is one of the best methods to prepare good quality and large amount of few-layer graphene sheets. We prepared pristine and doped graphene using chemical exfoliation through high energy tip sonication technique. The exfoliated graphene was later sintered for studying thermoelectric properties. The thermopower of these samples exhibits valleys, tentatively assigned to phonon drag, which shift towards higher temperature upon vacuum annealing and electron doping. Such a similar behavior was previously observed in doped carbon nanotubes. The effects of vaccum annealing and doping upon the fundamental behavior of thermoelectric power and thermal conduction of graphene will be presented.