Ultrafast exciton dynamics in semiconducting single-walled carbon nanotubes¶

¶We dedicate this paper to our friend and colleague Bob Harris, whose insights and capacity for wonder are a source of inspiration.

Abstract

To define the origin of the electronic excited states of single-walled carbon nanotubes, femtosecond fluorescence up-conversion and frequency-resolved transient absorption measurements were used for selective excitation/probing of particular nanotubes in a micelle-dispersed preparation enriched with individual nanotubes. Analysis of the temporal and intensity profiles of the transient signals enable one to unambiguously identify the excitonic nature of elementary excitations in semiconducting nanotubes, and the predominant dynamical process as a remarkable manifestation of exciton–exciton annihilation. These studies convincingly support the conclusion that the longest wavelength electronic excitations are of excitonic origin. In addition, evidence is shown for bi-exciton formation in single walled nanotubes.

¶We dedicate this paper to our friend and colleague Bob Harris, whose insights and capacity for wonder are a source of inspiration.

Acknowledgements

The work was supported by the NSF. L. V. was supported by a Fulbright scholarship during his time in Berkeley. We thank J. Stenger and J. Zimmermann for their contributions to the experiments, and S. M. Bachilo and R. E. Smalley for providing the HiPco SWNT materials.

Notes

‡Permanent address: Institute of Physics, Savanoriu Ave. 231, 02300 Vilnius, Lithuania and Theoretical Physics Department, Faculty of Physics of Vilnius University, Sauletekio Ave. 9, build. 3, 10222 Vilnius, Lithuania.

§Permanent address: Department of Physics, Washington State University, Pullman, Washington 99164-2814.

¶We dedicate this paper to our friend and colleague Bob Harris, whose insights and capacity for wonder are a source of inspiration.

Additional information

Notes on contributors

L. Valkunas‡

‡Permanent address: Institute of Physics, Savanoriu Ave. 231, 02300 Vilnius, Lithuania and Theoretical Physics Department, Faculty of Physics of Vilnius University, Sauletekio Ave. 9, build. 3, 10222 Vilnius, Lithuania.

S. L. Dexheimer§

§Permanent address: Department of Physics, Washington State University, Pullman, Washington 99164-2814.