Electronic properties of C-substituted boron nanotubes: a first principles study

The pseudopotential calculations have been performed to study the effect of carbon impurity on the electronic nature of hexagonal ultrathin boron nanotubes. The structural stability and electronic properties of C-substituted BNTs have been evaluated by first principles calculations. Three conformations of BNTs viz. armchair (3,3), zigzag (5,0), and chiral (4,2), have been considered for examining the effects of carbon substitution. It is observed that carbon substituted hexagonal ultrathin BNTs become energetically more stable in contrast to pristine ones. It is revealed that all the C-substituted hexagonal BNTs are metallic and independent of chirality & impurity concentration. Thus, the chirality of C-substituted BNTs is controlled to a certain extent. These findings are also compared with available experimental and theoretical results. These metallic nanotubes are promising candidate as interconnects for nanodevices as well as field emission devices.