Abstract
We report on electrical resistance measurements of single multiwalled carbon nanotubes (MWNTs) in different environments (ambient air, H2, O2 and the electrolytes LiClO4, KCl, KMnO4 and H3PO3). The gate dependence is studied using back-gating, electrochemical gating and gates evaporated directly onto the nanotubes (NTs). MWNTs at room temperature are p-doped. Upon changing the environment a change of the doping state of the MWNTs is inferred from the linear resistance. The effect of the environment on the contacts is negligible in our experiments. The p-doping is proposed to originate from the specific adsorption of an oriented dipole layer of water on the nanotube, which is affected by the kind of ions.
Export citation and abstract BibTeX RIS