Photophysics of individual single-walled carbon nanotubes

COLL 53

Todd D. Krauss, krauss@chem.rochester.edu1, Lisa J. Carlson, lcarlso2@mail.rochester.edu1, and Libai Huang, huang-stevenson@anl.gov2. (1) Department of Chemistry, University of Rochester, Rochester, NY 14627, (2) Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439
Single-walled carbon nanotubes (SWNTs) are tubular graphitic molecules with exceptional and unusual mechanical, electrical, and optical characteristics. For instance, nanotubes can be either metallic or semiconducting depending on their particular molecular structure. Regarding their potential as novel materials for solar energy conversion, the optical properties of SWNTs are particularly important. For example, semiconductor nanotubes are efficient light absorbers in the near infrared, and thus have the potential to generate multiple charge carriers per photon absorbed. Combining this feature with their macroscopic lengths that allow for efficient charge transport, SWNTs have intriguing potential as materials for future solar cells. In this context, we will present several aspects of the photophysics of carbon nanotubes: their fundamental optical excitations (which are one-dimensional bound electron–hole pairs), their robust and unexpectedly unwavering single molecule fluorescence, and their excited state dynamics on ultrafast time scales, including the quantized annihilation of electron–hole pairs.