Broadband Absolute Absorption Cross-Section of
Individual Free-Standing Single-Wall Carbon Nanotubes

Jean-Christophe Blancona*, Matthieu Pailletb, Huy Nam Tranb, Dimitry Levshovb, Xuan Tinh Thanb, Samuel Aberra Guebroua, Anthony Ayaria, Alfonso San Miguela, Ahmed Azmi Zahabb, Jean-Louis Sauvajolb, Natalia Del Fattia, Fabrice Valléea

aInstitut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, Villeurbanne, France.
b
Laboratoire Charles Coulomb UMR 5221, Université Montpellier 2-CNRS, Montpellier, France.

The unique optical properties of single-wall carbon nanotubes (SWNTs) are appealing for the development of novel applications in optoelectronic and biology. Despite the large amount of data collected with photoluminescence, Raman spectroscopy and Rayleigh scattering, direct access to the intrinsic absorption characteristics of these nano-objects is still challenging. The understanding of absorption processes occurring in carbon nanotubes is crucial, and more precisely this comprehension should occur at the individual nanotube level. Values of absorption cross-section were reported using photoluminescence [1], photo-thermal spectroscopy [2], and Rayleigh scattering [3], but are indirect measurements requiring hypotheses on the absorption processes taking place in carbon nanotubes.

Here we present direct measurements of the absolute absorption cross-section of individual carbon nanotubes using the spatial modulation spectroscopy technique developed in our lab [4,5]. We obtained the first broadband polarized absorption spectra of individual free-standing SWNTs identified with Raman spectroscopy. These results are compared with measurements performed on carbon nanotubes either deposited on a substrate or assembled in bundle. Clear modifications of the light-matter interactions are observed depending on the nanotubes environment, as shown through energy shifts and broadenings of the excitonic resonance peaks as well as weakening of antenna effects.

References

[1] S. Berciaud, L. Cognet, B. Lounis, et al., Physical Review Letters 101(7) (2008) 077402.
[2] S. Berciaud, L. Cognet, P. Poulin, et al., Nano Letters 7(5) (2007) 1203.
[3] D. Y. Joh, J. Kinder, L. H. Herman, et al., Nature Nanotechnology 6(1) (2011).  51
[4] A. Arbouet, D. Christofilos, N. Del Fatti, et al., Physical Review Letters 93 (2004) 127401.
[5] D. Christofilos, J.-C. Blancon, J. Arvanitidis, et al., Journal of Physical Chemistry Letters 3 (2012) 1176.