Exciton annihilation and dephasing dynamics in semiconducting single-walled carbon nanotubes

Matthew W. Graham, Ying Zhong Ma, Alexander A. Green, Mark C Hersam, Graham R. Fleming

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)

Abstract

Semiconducting single-walled carbon nanotubes (SWNTs) are one of the most intriguing nanomaterials due to their large aspect ratios, size tunable properties, and dominant many body interactions. While the dynamics of exciton population relaxation have been well characterized, optical dephasing processes have only been examined indirectly through steady-state measurements such as single-molecule spectroscopy that can yield highly variable estimates of the homogeneous linewidth. To bring clarity to these conflicting estimates, a time-domain measurement of exciton dephasing at an ensemble level is necessary. Using two-pulse photon echo (2PE) spectroscopy, comparatively long dephasing times approaching 200 fs are extracted for the (6,5) tube species at room temperature. In this contribution, we extend our previous study of 2PE and pump-probe spectroscopy to low temperatures to investigate inelastic exciton-exciton scattering. In contrast to the population kinetics observed upon excitation of the second transition-allowed excitonic state (E22), our one-color pump-probe data instead shows faster relaxation upon cooling to 60 K when the lowest transition-allowed state (E11) is directly excited for the (6,5) tube species. Analysis of the kinetics obtained suggests that the observed acceleration of kinetic decay at low temperature originates from an increasing rate of exciton-exciton annihilation. In order to directly probe exciton-exciton scattering processes, femtosecond 2PE signal is measured as a function of excitation fluence and temperature. Consistent with the observed enhancement of exciton-exciton scattering and annihilation at low temperatures, the dephasing rates show a correlated trend with the temperature dependence of the population lifetimes extracted from one-color pump-probe measurements.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
Volume7600
DOIs
Publication statusPublished - 2010
EventUltrafast Phenomena in Semiconductors and Nanostructure Materials XIV - San Francisco, CA, United States
Duration: Jan 24 2010Jan 27 2010

Other

OtherUltrafast Phenomena in Semiconductors and Nanostructure Materials XIV
CountryUnited States
CitySan Francisco, CA
Period1/24/101/27/10

Fingerprint

Single-walled Carbon Nanotubes
Exciton
Single-walled carbon nanotubes (SWCN)
Annihilation
Excitons
carbon nanotubes
excitons
Probe
Pump
Spectroscopy
probes
Kinetics
Scattering
Pumps
pumps
Temperature
Tube
kinetics
Photon Echo
Excitation

Keywords

  • Dephasing
  • Excitons
  • Population dynamics
  • Single-walled carbon nanotubes
  • Ultrafast nonlinear spectroscopy

ASJC Scopus subject areas

  • Applied Mathematics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Graham, M. W., Ma, Y. Z., Green, A. A., Hersam, M. C., & Fleming, G. R. (2010). Exciton annihilation and dephasing dynamics in semiconducting single-walled carbon nanotubes. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 7600). [76001F] https://doi.org/10.1117/12.841194

Exciton annihilation and dephasing dynamics in semiconducting single-walled carbon nanotubes. / Graham, Matthew W.; Ma, Ying Zhong; Green, Alexander A.; Hersam, Mark C; Fleming, Graham R.

Proceedings of SPIE - The International Society for Optical Engineering. Vol. 7600 2010. 76001F.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Graham, MW, Ma, YZ, Green, AA, Hersam, MC & Fleming, GR 2010, Exciton annihilation and dephasing dynamics in semiconducting single-walled carbon nanotubes. in Proceedings of SPIE - The International Society for Optical Engineering. vol. 7600, 76001F, Ultrafast Phenomena in Semiconductors and Nanostructure Materials XIV, San Francisco, CA, United States, 1/24/10. https://doi.org/10.1117/12.841194
Graham MW, Ma YZ, Green AA, Hersam MC, Fleming GR. Exciton annihilation and dephasing dynamics in semiconducting single-walled carbon nanotubes. In Proceedings of SPIE - The International Society for Optical Engineering. Vol. 7600. 2010. 76001F https://doi.org/10.1117/12.841194
Graham, Matthew W. ; Ma, Ying Zhong ; Green, Alexander A. ; Hersam, Mark C ; Fleming, Graham R. / Exciton annihilation and dephasing dynamics in semiconducting single-walled carbon nanotubes. Proceedings of SPIE - The International Society for Optical Engineering. Vol. 7600 2010.
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