Abstract:
A single sheet of sp2- hybridized carbon atoms, called graphene, is presently the most widely studied material in the scientific community. Following a brief introduction of graphene and its unique properties, I will present two popular methods for preparing graphene for spectroscopic studies. In carbon science, spectroscopy has played a significant role in unraveling several fundamental properties of nanostructured carbons like fullerenes and carbon nanotubes. Drawing from such spectroscopic studies, the effective roles of Raman and UV-vis spectroscopy in elucidating the the vibration and electronic properties of graphene will be discussed. Specifically, the effects of crystallite size (La) on the linear and non-linear optical properties of chemical vapor deposition grown polycrystalline graphene will be presented.  In comparison to epitaxial graphene layers grown on SiC wafers which ehibit a photogenerated carrier lifetime of few picoseconds, we find that the photogenerated carriers in our CVD-grown graphene can exhibit lifetimes as long as nanoseconds. Time permitting, preliminary data on doped graphene will also be discussed.