Carbon nanotubes intercalated by metal atoms with impurity boron atoms as a basis for creating nanowires: theoretical research

Abstract

Carbon nanotubes are one of the currently sought after nanotechnology materials. But the issue of controlling their physicochemical properties, in particular, for creating nanowires by intercalating metal atoms in them, has not yet been fully studied. In this case, there is an effective way to control the electronic energy characteristics — the introduction of impurity atoms. Boron is the most effective among this class of substituting elements. Therefore, the purpose of this article is to study the possibility of internal filling of carbon nanotubes with impurity boron atoms with various metal atoms and to determine the role of its concentration on the phenomena occurring in this case. Using the density functional theory, a model experiment was carried out on the introduction into the cavity of a nanotube of aluminum atoms, as well as alkali metals - lithium, sodium and potassium. The model experiment showed that in all cases the formation of a stable adsorption complex takes place, which can be considered as a model of a nanowire with multiple filling with atoms between the nanotube and metal atoms. At the same time, it was found that during the formation of complex compounds “nanotube — metal atom”, the electron density is redistributed in the system, namely, it is shifted from the B atoms of the metals to the surface of the nanotube, which leads to the formation of additional charge carriers transferred from the donor. Also, an analysis of the electron-energy structure made it possible to establish that the band gap for BC3 nanotubes narrows during the intercalation of metal atoms. This conclusion is extremely important for the needs of nanoelectronics, since it makes it possible to predict the more efficient use of carbon nanotubes with a higher concentration of impurity boron atoms to create nanodevices due to the appearance in them of conducting properties that are different from pure nanostructures, which are expressed in the appearance of additional charge carriers.