Structural dependence of exciton in carbon nanotubes
Group of Computational Condensed Matter Physics, National Laboratory of Solid State Microstructures and Dept. of Physics, Nanjing University, Nanjing, 210093, P.R. China
Corresponding author: a email@example.com
Revised: 31 December 2007
Published online: 13 March 2008
The binding energies and sizes of excitons, and energy splitting of the bright-dark excitons in single-walled carbon nanotubes have been calculated using the nonorthogonal tight-binding model, supplemented by the long-range Coulomb interaction. It is found that the binding energies and the sizes of excitons not only depend on tube's diameter d, but also its chirality. However, the splitting of the bright-dark excitons mostly depends on 1/d2. Our obtained results show that the curvature effect is very important for the exciton excitations in the SWNTs, especially in the smaller diameter ones.
PACS: 78.67.Ch – Nanotubes / 73.22.-f – Electronic structure of nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals / 71.35.-y – Excitons and related phenomena
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008