|Type of Publication:||Article|
|Journal:||Physica Status Solidi B-Basic Solid State Physics||Volume:||243|
PT: J; CT: 8th International Workshop on Nonlinear Optics and Excitation Kinetics In Semiconductors (NOEKS 8); CY: FEB 20-24, 2006; CL: Munster, GERMANY; TC: 1; UT: WOS:000239932300037
We compare experimental one- and two-photon luminescence excitation spectra of single-walled carbon nanotubes at room temperature to ab initio calculations. The experimental spectra reveal a Rydberg-like series of excitonic states. The energy splitting between these states is a clear fingerprint of excitonic correlations in carbon nanotubes. From those spectra, we derive exciton binding energies of 0.3-0.4 eV for nanotubes with diameters between 6.8 angstrom and 9.0 angstrom. These energies are in quantitative agreement with our nanotubes with diameters between 6.8 angstrom and 9.0 angstrom. These energies are in quantitative agreement with our theoretical calculations, which predict the symmetries of the relevant excitonic wave functions and indicate that a low-lying optically dark excitonic state may be responsible for the low luminescence quantum yields in nanotubes. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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