Abstract
The speaker explores the fundamental nature and dynamics of electrons in graphic 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, grapheme, 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.
About the speaker
Prof Louis Brus received his PhD in Chemical Physics from Columbia University in 1969. He joined AT&T Bell Laboratories in 1973 and was Distinguished Member of Technical Staff from 1984 to 1996. He joined Columbia University in 1996, and was Professor of Chemistry, Chemical Engineering and Applied Chemistry. He was Thomas Alva Edison Professor from 2001 to 2004. He is currently Samuel Latham Mitchill Professor.
Prof Brus’s current research interests focus on the physical chemistry of materials, interfaces, nanocrystals, and nanotubes, especially in relation to optical and electronic properties. These include theoretical modeling, experimental chemical physics, and synthetic chemistry. His research group tries to understand the size evolution of solid-state properties from molecular properties, and seeks to create new materials with nanoscale structure by both kinetic and thermodynamic self-assembly methods. The group specializes in Electric Force Microscopy and Laser Optical Microscopy for observation of single nano-objects. In the last several years, the group has developed interests in metallic SWNT carbon nanotubes, and in Ag nanocrystals as microscopic antennas for local electromagnetic field enhancement.
Prof Brus is a Member of the US National Academy of Sciences (NAS) and the Norwegian Academy of Science and Letters. He is also a Fellow of the American Academy of Arts and Sciences and the American Physical Society. He received numerous prestigious awards including the NAS Award in Chemical Sciences in 2010 and the Inaugural Kavli Prize for nanoscience in 2008.
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