NANOCOLLOQUIUM: Louis Brus - Carbon Nanoscience and Electronic Structure
Louis E. Brus, a professor at Columbia University in New York and the winner of the first Kavli prize in Nanoscience, will speak at the University of Maryland on February 1, 2013, at 3 pm.
Prof. Brus' research spans multiple frontiers of the physical chemistry of materials. He is best known for his work on quantum dots, which straddle the physical line between semiconductors and molecules. This unique substance can be used in applications such as transistors, solar cells, LEDs, and diode lasers; as agents for medical imaging; and possibly as qubits in quantum computing.
The presentation is the first NanoColloquium of 2013 from the Maryland NanoCenter, and is also a part of the Distinguished Speaker Seminar Series presented by the College of Mathematical and Natural Sciences Department of Chemistry and Biochemistry.
The session will be held in the Marker Seminar Room of the Chemistry Building (Room 0112) from 3:00-4:00pm. Light refreshments will be served at 2:30pm.
Abstract by Dr. Brus: 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.