NANOPHENSIM · COMPUTER SIMULATIONS OF OPTICAL AND TRANSPORT PHENOMENA IN CARBON NANOTUBES

The growing realisation of the immense potential for applications of the carbon nanotubes has attracted much attention of scientists. Presently, the nanotube research has become one of the most intensively developing areas of nanotechnology. The principal reason for the amazing electronic and vibrational properties of the nanotubes stems in their quasi-one-dimensionality. The initially existing principal obstacle of normally very large nanotube unit cells, which hindered most of the atomistic simulations on perfect nanotubes, has recently been overcome by using of the screw symmetry of the nanotubes. This allowed for large-scale calculations of phonon dispersion and electronic structure, as well as various optical, thermal, and mechanic properties, of any nanotube of practical interest. The principal objectives of this project are the extension of this symmetry-adapted approach to calculations of other properties and phenomena in nanotubes, which have not been addressed in detail so far. The major topics to be encompassed by the project are: 1) exciton effects, which are of major importance for the optical processes in nanotubes as evidenced by experiments and supported by theoretical arguments, 2) second-order Raman scattering, which can be a source of information for the electronic structure and phonon dispersion of nanotubes but has been described qualitatively only in several limited cases, 3) the phenomenon of photoluminescence, which provides direct information for the structural properties of carbon nanotubes and for the electron (or exciton) – phonon scattering processes, but has not received much attention by theorists, and finally, 4) thermal and electronic transport in nanotubes, which are basic phenomena with importance for building up nano-electronic devices.