Article pubs.acs.org/JPCC
Transient Absorption Kinetics Associated with Higher Exciton States in Semiconducting Single-Walled Carbon Nanotubes: Relaxation of Excitons and Phonons Takeshi Koyama,*,† Shohei Yoshimitsu,† Yasumitsu Miyata,‡ Hisanori Shinohara,‡ Hideo Kishida,† and Arao Nakamura†,§ †
Department of Applied Physics, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan § Toyota Physical and Chemical Research Institute, Nagakute, Aichi 480-1192, Japan ‡
S Supporting Information *
ABSTRACT: We investigate the transient absorption kinetics due to excitons associated with the first and higher transition states in semiconducting single-walled carbon nanotubes at high excitation densities by means of femtosecond pump− probe spectroscopy. The time evolutions of absorption changes associated with the first, second, and third excitonic transition bands exhibit similar decay behavior; the decay is much longer than the exciton population decay observed by time-resolved luminescence measurements. From spectral shape analysis of the transient absorption spectra, it is found that the absorption change in the short time regime (
