Diameter Dependence of the Dielectric Constant for the Excitonic Transition Energy of Single-Wall Carbon Nanotubes
The measured optical transition energies Eii of single-wall carbon nanotubes are compared with bright exciton energy calculations. The Eii differences between experiment and theory are minimized by considering a diameter-dependent dielectric constant κ, which comprises the screening from the tube an...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Physical Society
2010
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| Online Access: | http://hdl.handle.net/1721.1/51761 https://orcid.org/0000-0001-8492-2261 |
| Summary: | The measured optical transition energies Eii of single-wall carbon nanotubes are compared with bright exciton energy calculations. The Eii differences between experiment and theory are minimized by considering a diameter-dependent dielectric constant κ, which comprises the screening from the tube and from the environment. Different κ dependencies are obtained for (E[subscript 11]S, E[subscript 22]S, E[subscript 11]M) relative to (E[subscript 33]S, E[subscript 44]S). A changing environment changes the κ diameter dependence for (E[subscript 11]S, E[subscript 22]S, E[subscript 11]M), but for (E[subscript 33]S, E[subscript 44]S) the environmental effects are minimal. The resulting calculated exciton energies reproduce experimental Eii values within ±70 meV for a diameter range (0.7<dt<3.8 nm) and 1.2<Eii<2.7 eV, thus providing a theoretical justification for Eii, environmental effects and important insights on the dielectric screening in one-dimensional structures. |
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