Study of nitrogen doping of graphene via in-situ transport measurements

Here we report in-situ monitoring of electrical transport properties of graphene subjected to sequential and controlled nitrogen plasma doping. The nitrogen is presumed to be incorporated in to the carbon lattice of graphene by making covalent bonding as observed by the swinging of the sign of the thermopower from (initial) positive to (eventual) negative. Electrical transport properties for nitrogen-doped graphene are believed to be governed by the enhanced scattering due to nitrogen dopants and presence of localized states in the conduction band induced by doping. Our results are well supported by Raman and XPS results.