Nanotube know how
1 min read
Research published by the University of Surrey has determined that knowing the structure of the surface layer of a multilayer carbon nanotube is not enough to predict its electronic properties. The team claim the contribution of inner layers is crucial and this has serious implications when it comes to fabricating electronic devices, such as transistors and molecular interconnects.
Cristina Giusca, the lead author of the paper said: “The work is of fundamental importance to the carbon community as it shows the first evidence for a direct correlation between the electronic properties of multiwall carbon nanotubes and the diameter and chiral indices (helicity) of the inner shells.”
Single wall carbon nanotubes can be regarded as single atom thick sheets of graphite which are wrapped up to form tubes. It is the diameter of the tube and the degree of helicity in this wrapping which determine the electronic properties. Different configurations can result in the tube behaving either as a metallic conductor or as a semiconductor and this theoretically predicted relationship between the structure and electronic properties has been confirmed using scanning tunnelling microscopy.
Surrey’s experiments used scanning tunnelling microscopy of double walled carbon nanotubes to demonstrate an explicit correlation between the helicity of the constituent tubes, their electronic coupling and the overall electronic structure.
