When: Friday, February 01, 2013 2:30 PM - 4:00 PM
Where: Chemistry : Marker Seminar Room : 0112
Event Type(s): Colloquium

Title: Carbon Nanoscience and Electronic Structure.
We explore the fundamental nature and dynamics of electrons in graphitic carbon materials. In semiconducting carbon nanotubes, near-infrared two photon luminescence excitation spectra quantitatively reveal very-strongly-bound exciton excited states. Electron-electron interactions are compared among CdSe nanocrystals, graphene, and carbon nanotubes. The independent contributions of screening and dimensionality are analyzed. Electronic and vibrational degrees of freedom are significantly coupled in graphene. The metallic versus molecular nature of single sheet graphene is strongly affected by charge transfer doping by adsorbed molecular species. Asymmetric doping in bilayer graphene can open a band gap, as revealed by the Raman spectra. Optical absorption bleaching and Raman Fano lineshapes are observed in few layer graphenes very highly doped by adsorbed alkalis.

For more information, contact:
YuHuang Wang
yhw@umd.edu