These objects have physical characteristics that are derived from the bulk material, but also are strong functions of its size and shape. Thus, nanometer scale materials have properties that can be easily controlled and manipulated. This size dependence gives nanomaterials the potential for numerous applications ranging from novel non-linear optical devices to biological markers. Currently, our investigations are focused on carbon nanotubes and semiconductor nanocrystals, and the integration of these materials into novel photonic devices. These studies are highly interdisciplinary, and lie at the interface between chemistry, physics, applied physics, and materials science.
Carbon nanotubes consist of a hexagonal network of carbon atoms rolled up into a cylinder.
The length of these cylinders is typically a few microns, while the diameter is usually a few nanometers. The confinement of electrons in the radial direction of the cylinder results in unexpected electronic properties. For example, these molecules surprisingly can be either metallic or semiconducting, depending on the diameter and helicity of the carbon lattice. We are concerned with determining the fundamental electronic and optical characteristics of individual carbon nanotubes. These investigations are carried out using atomic force microscopic in conjunction with optical spectroscopic methods.