Eur. Phys. J. B (2013) 86: 45
https://doi.org/10.1140/epjb/e2012-30610-4

Regular Article

Intra- and inter-tube exciton relaxation dynamics in high purity semiconducting and metallic single-walled carbon nanotubes^*

¹ Department of Physics, Konan University, 658-8501 Kobe, Japan
² National Institute for Information and Communications Technology, 651-2492 Kobe, Japan
³ Department of Chemistry, Faculty of Science, Nagoya University, 464-8601 Nagoya, Japan
⁴ Department of Physics, Faculty of Science, Tokyo Metropolitan University, 192-0364 Tokyo, Japan
⁵ Nanotechnology Research Institute, Advanced Industrial Science and Technology, 305-8562 Tsukuba, Japan

^a e-mail: ichida@konan-u.ac.jp

Received: 16 July 2012
Received in final form: 7 November 2012
Published online: 11 February 2013

Abstract

We have measured the exciton and carrier dynamics in the high purity semiconducting (S-) and metallic (M-) single-walled carbon nanotubes (SWNTs) in the isolated and aggregated (bundled) forms. The exciton relaxation decay times are measured by using the pump-probe spectroscopy. For bundled samples, the relaxation time becomes shorter than that for isolated SWNTs sample, because of the existence of inter-tube relaxation. We estimate the relaxation rates from S-SWNT to S-SWNT and S-SWNT to M-SWNT using the decay times for isolated SWNTs, high purity S-SWNTs bundle, and doped S-SWNTs in high purity M-SWNTs bundle. For S-SWNTs, inter-tube relaxation plays an important role in the relaxation dynamics. However, for M-SWNTs, the inter-tube relaxation is not so important, and the transition energy and intensity of exciton in M-SWNTs is strongly affected by the photoexcited carriers which plays like as photo doping.