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 (ON), 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