Monday, May 24, 20103:00 PM - 4:00 PMCNLS Conference Room (TA-3, Bldg 1690)|
Nano is more than size: The role of geometry in the electronic structure and optical response of carbon nanostructures
Vincent CrespiPennsylvania State University
The atomic-scale order of highly deformable yet chemically inert carbon frameworks animates a wide range of novel structural, optical, and electronic phenomena. For example, mechanical manipulation of a carbon nanotube, followed by chemical functionalization, can split the tube into two independent channels whose extremely weak and tunable interaction generates a new energetic regime. The skewed orientation of the two weakly interacting adjacent layers of a folded graphene monolayer activates a new non-dispersive Raman band which is pinned to the wave-vectors of the periodic but incommensurate interlayer perturbing potential. Also, the division of surrounding space into two disconnected zones by an impenetrable suspended graphenic sheet enables adsorption of otherwise highly co-reactive species, such as alkali and halogen, in opposite subspaces, with an intense cross-sheet charge transfer that produces a new variant of ionic binding with a uncompensated electrostatic dipoles.
Host: Cristiano Nisoli, T-4/CNLS