Electronic properties of electrochemically modified single-walled carbon nanotubes

The functionalization of carbon nanotubes is a research topic with applications in a wide range of fields, from carbon nanotube based electronic sensor development to improving the electrical properties of carbon nanotubes for use as interconnects between larger circuit elements. This dissertation examines the impact of point-functionalizations on the conductance of single carbon nanotube devices. Due to their reduced size and dimensionality, carbon nanotubes act as an ideal system to electronically probe the characteristics of single functionalizations. Point-functionalizations can easily be introduced into carbon nanotube sidewalls using an electrochemical technique, which allows the experimenter to have total control over the rate of functionalization. The presence of point-functionalizations dominates the electronic properties of carbon nanotube devices. In this work, these sites are shown to be more chemically reactive, allowing metal nanoparticles to be selectively nucleated and grown on functionalized sites. Additionally, the presence of a single functionalized site coupled to a single palladium nanoparticle can be used to make a single carbon nanotube hydrogen sensor, with sensitivity down to the part per million level. Finally, cyclic voltammetry experiments show that point-functionalizations have much faster electron transfer rates than pristine carbon nanotubes alone