Imaging and Spectroscopy of Carbon Nanotubes and Graphene using Photons and Electrons

The fundamental interactions of optical photons and electrons with multi-walled carbon nanotubes (MWCNTs) and graphene are investigated both theoretically and experimentally. Theoretical investigations have resulted in the discovery of a new type of angular momentum which emerges from the intrinsic geometric crystal structure of graphene. This new angular momentum is shown theoretically to be related to graphene's optical absorption. The angular dependent optical transmission of graphene is measured and compared to semi-classical and quantum models. A quantitative distinction between graphene and bilayer graphite crystal structures is calculated from first principles and measured using electron diffraction. Experimental investigations into the structural. thermal, and electronic properties of MWCNTs are conducted using transmission electron microscopy, optical pyrometry, and optical spectroscopy. MWCNTs are Joule heated to ∼ 2000 K to better understand their thermal emission properties. A model for the current-voltage relationship in MWCNTs is developed to understand the physics of these novel thermal emitters.