Band structure of boron doped carbon nanotubes

We present ab initio and self‐consistent tight‐binding calculations on the band structure of single wall semiconducting carbon nanotubes with high degrees (up to 25 %) of boron substitution. Besides a lowering of the Fermi energy into the valence band, a regular, periodic distribution of the p‐dopants leads to the formation of a dispersive “acceptor”‐like band in the band gap of the undoped tube. This comes from the superposition of acceptor levels at the boron atoms with the delocalized carbon π‐orbitals. Irregular (random) boron‐doping leads to a high concentration of hybrids of acceptor and unoccupied carbon states above the Fermi edge.