Two-dimensional graphene exhibits many fascinating properties such as
ballistic electronic conduction and quantum Hall effect at room temperature.1-4
Graphene doped electrochemically or through charge-transfer with electron-donor
and -acceptor molecules,5-7 shows marked changes in electronic structure, with
characteristic signatures in the Raman spectra.5-10 Substitutional doping,
universally used in tuning properties of semiconductors, could be a powerful
tool to control the electronic properties of graphene. Here, we present the
structure and properties of boron and nitrogen doped graphenes, obtained by
more than one method involving arc discharge in appropriate gaseous atmosphere,
by using modified graphite electrode or by the transformation of nano-diamond.
Using a combination of experiment and firstprinciples theory, we demonstrate
systematic changes in the carrier-concentration and electronic structure of
graphenes with B/N-doping, accompanied by stiffening of the Gband and
intensification of the defect related D-band in the Raman spectra. Such n/p -
type graphenes obtained without external fields or chemical agents should find
device applications.Comment: 12 pages, 5 figures, 1 tabl
