Electronic and structural properties of oxygen-doped BN nanotubes

The structural and electronic properties of oxygen substitutional doping in a (10,0) BN nanotube were obtained using ab initio calculation based on the density functional theory. For the oxygen replacing a boron atom in the tube (O-B), the structure is locally deformed. In the case of nitrogen substitution (O-N), however, the tube structure remains practically the same with negligible deformation observed around the oxygen atom. The electronic band structure for O-B nanotubes is modified by the appearance of three strongly localized states, two of then as gap states. In the case Of O-N nanotubes the Fermi level is shifted into the conduction band inducing a metallic character to the doped tube. The analysis of the formation energies shows that the O-N substitution is more favorable, particularly in the case of a boron-rich environment.