Electronic and doping properties of BxCyNz nanotubes

Theoretical studies of the electronic and structural properties of BxCyNz nanotubes are presented. Nanotubes of BN, BC3 and BC2N are predicted to form and have very different properties from those of carbon. BN nanotubes are constant band-gap insulator with a novel free electron state as conduction band minimum and behave as non-interacting host for metal nanowires. The conductivity of this metal-tubules is through carriers located at the inner part of the tube. In contrast, C-nanotubes presents two types of interactions: charge-transfer (dominant for alkali atoms) and leads to strong: binding, and hybridization (for multivalence atoms) resulting in a smaller cohesion. New electronic properties related to the low-dimensionality of this nanowires are analyzed. For C-tubes we discuss the quantum finite-size and capping effects in the electronic properties.