Rayleigh Scattering Spectroscopy

Single-wall carbon nanotubes can be probed optically by elastic light scattering. This effect forms the basis of a technique, termed Rayleigh scattering spectroscopy, for the study of individual nanotubes. Spectroscopic information on the electronic transitions of both semiconducting and metallic nanotubes is obtained by measuring the elastic scattering cross section as a function of photon energy. In this contribution, we describe the basic principles of the Rayleigh scattering method and its experimental implementation for the rapid and precise measurement of nanotube electronic spectra. The capabilities of the technique are illustrated with several examples of its application. The method offers a natural approach to investigate polarization effects and the persistence of the chiral structure of an individual nanotube, as well as a means to probe nanotube–nanotube interactions. Rayleigh scattering spectroscopy is also well suited for combination with other experimental techniques for the characterization of individual nanotubes. This possibility is illustrated by measurements of the Rayleigh spectra of individual nanotubes with chiral indices independently determined by electron-diffraction measurements.