| Carbon nanotubes are highly promising for building electronic devices because of their quasi-unidimensional nanometer-sized geometry, and their mechanical and electronic properties, including their remarkable electrical conductance. Their functionalized derivatives, in which the nanotube sidewall is chemically modified, are also interesting for their better processability and for creating a chemically active interface between the nanotube and the environment, which is essential for applications such as nanosensors or biosensors. In this thesis, we study the mechanisms governing electrical transport in carbon nanotubes and their functional derivatives. Our experimental work was performed on electronic devices made of individual single-walled or double-walled carbon nanotubes, with or without functional adducts. In the first part, we focus on the effect of reduced dimensionality on the physics of charge injection at electrical contacts. In the second part, we study the effect of covalent functionalization on carbon nanotubes electrical transport properties. We show that the impact of chemical addition is strongly dependent on graft valence, and that it is possible to produce covalently functionalized carbon nanotube devices with excellent electrical conductance. In the third part, we explore current saturation and electrical breakdown phenomena occurring at high bias. Finally, the impact of our results on the global understanding of electrical transport in highly confined systems is discussed, along with fundamental and technological perspectives unveiled by our work. |
