Scaling of exciton binding energy with external dielectric function in carbon nanotubes
Files
Final author draft
Date
2008-05-01
Authors
Walsh, Andrew G.
Vamivakas, A. Nickolas
Yin, Yan
Cronin, Stephen B.
Unlu, M. Selim
Goldberg, Bennett B.
Swan, Anna K.
Version
OA Version
Citation
A.G. Walsh, A.N. Vamivakas, Y. Yin, S.B. Cronin, M.S. Unlu, B.B. Goldberg, A.K. Swan. 2008. "Scaling of exciton binding energy with external dielectric function in carbon nanotubes." PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES, Volume 40, Issue 7, pp. 2375 - 2379. https://doi.org/10.1016/j.physe.2007.07.007
Abstract
We develop a scaling relationship between the exciton binding energy and the external dielectric function in carbon nanotubes. We show that the electron–electron and electron–hole interaction energies are strongly affected by screening yet largely counteract each other, resulting in much smaller changes in the optical transition energy. The model indicates that the relevant particle interaction energies are reduced by as much as 50% upon screening by water and that the unscreened electron–electron interaction energy is larger than the unscreened electron–hole interaction energy, in agreement with explanations of the “ratio problem.” We apply the model to measurements of the changes in the optical transition energies in single, suspended carbon nanotubes as the external dielectric environment is altered.