title: (n,m)-Specific Absorption Cross Sections of Single-Walled Carbon Nanotubes Measured by Variance Spectroscopy.
abstract: A new method based on variance spectroscopy has enabled the determination of absolute absorption cross sections for the first electronic transition of 12 (n,m) structural species of semiconducting single-walled carbon nanotubes (SWCNTs). Spectrally resolved measurements of fluorescence variance in dilute bulk samples provided particle number concentrations of specific SWCNT species. These values were converted to carbon concentrations and correlated with resonant components in the absorbance spectrum to deduce (n,m)-specific absorption cross sections (absorptivities) for nanotubes ranging in diameter from 0.69 to 1.03 nm. The measured cross sections per atom tend to vary inversely with nanotube diameter and are slightly greater for structures of mod 1 type than for mod 2. Directly measured and extrapolated values are now available to support quantitative analysis of SWCNT samples through absorption spectroscopy.
authors.affiliation: Department of Chemistry and the Smalley-Curl Institute and ‡Department of Materials Science and NanoEngineering, Rice University , 6100 Main Street, Houston, Texas 77005, United States.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Sanchez
authors.affiliation: Department of Chemistry and the Smalley-Curl Institute and ‡Department of Materials Science and NanoEngineering, Rice University , 6100 Main Street, Houston, Texas 77005, United States.
authors.forename: Sergei M
authors.initials: SM
authors.lastname: Bachilo
authors.affiliation: Department of Chemistry and the Smalley-Curl Institute and ‡Department of Materials Science and NanoEngineering, Rice University , 6100 Main Street, Houston, Texas 77005, United States.
authors.forename: Yara
authors.initials: Y
authors.lastname: Kadria-Vili
authors.affiliation: Department of Chemistry and the Smalley-Curl Institute and ‡Department of Materials Science and NanoEngineering, Rice University , 6100 Main Street, Houston, Texas 77005, United States.
authors.forename: Ching-Wei
authors.initials: CW
authors.lastname: Lin
authors.affiliation: Department of Chemistry and the Smalley-Curl Institute and ‡Department of Materials Science and NanoEngineering, Rice University , 6100 Main Street, Houston, Texas 77005, United States.
authors.forename: R Bruce
authors.initials: RB
authors.lastname: Weisman
keywords: SWCNT; SWIR spectroscopy; absorption cross section; fluctuation spectroscopy; molar absorptivity; quantitative analysis