BN domains included into carbon nanotubes: role of interface

TL;DR

This study uses density functional theory to explore how small BN domains embed into carbon nanotubes, revealing stable configurations, interface chemistry, and electronic effects such as band gap opening and potential n-doping.

Contribution

It introduces a detailed theoretical analysis of BN domain formation in carbon nanotubes, highlighting the role of N-C bonds and nitrogen termination in stabilization.

Findings

BN hexagons tend to form within CNT walls.

BN-C interfaces favor N-C bonds and nitrogen-terminated borders.

Inclusion of BN domains opens a band gap and introduces donor states.

Abstract

We present a density functional theory study on the shape and arrangement of small BN domains embedded into single-walled carbon nanotubes. We show a strong tendency for the BN hexagons formation at the simultaneous inclusion of B and N atoms within the walls of carbon nanotubes. The work emphasizes the importance of a correct description of the BN-C frontier. We suggest that BN-C interface will be formed preferentially with the participation of N-C bonds. Thus, we propose a new way of stabilizing the small BN inclusions through the formation of nitrogen terminated borders. The comparison between the obtained results and the available experimental data on formation of BN plackets within the single walled carbon nanotubes is presented. The mirror situation of inclusion of carbon plackets within single walled BN nanotubes is considered within the proposed formalism. Finally, we show that the inclusion of small BN plackets inside the CNTs strongly affects the electronic character of the initial systems, opening a band gap. The nitrogen excess in the BN plackets introduces donor states in the band gap and it might thus result in a promising way for n-doping single walled carbon nanotubes.