[en] We report a detailed experimental and theoretical study on the electronic and optical properties of highly boron-substituted (up to 15 at.%) single-wall carbon nanotubes. Core-level electron energy-loss spectroscopy reveals that the boron incorporates into the lattice structure of the tubes, transferring similar to1/2 hole per boron atom into the carbon derived unoccupied density of states. The charge transfer and the calculated Fermi-energy shift in the doped nanotubes evidence that a simple rigid-band model can be ruled out and that additional effects such as charge localization and doping induced band-structure changes play an important role at this high doping levels. In optical absorption a new peak appears at 0.4 eV which is independent of the doping level. Compared to the results from a series of ab initio calculations our results support the selective doping of semiconducting nanotubes and the formation of BC3 nanotubes instead of a homogeneous random boron substitution.
Disciplines :
Physics
Author, co-author :
Fuentes, G. G.; Leibnitz-Institute für Festkörper- und Werkstoffforschung Dresden
Borowiak-Palen, E.; Leibnitz-Institute für Festkörper- und Werkstoffforschung Dresden
Knupfer, M.; Leibnitz-Institute für Festkörper- und Werkstoffforschung Dresden
Pichler, T.; Leibnitz-Institute für Festkörper- und Werkstoffforschung Dresden
Fink, J.
Wirtz, Ludger ; Department of Material Physics, University of the Basque Country, Centro Mixto CSIC-UPV, and Donostia International Physics Center
Rubio, A.; Department of Material Physics, University of the Basque Country, Centro Mixto CSIC-UPV, and Donostia International Physics Center
Language :
English
Title :
Formation and electronic properties of BC3 single-wall nanotubes upon boron substitution of carbon nanotubes