Quantitative analysis of isolated single-wall carbon nanotubes with their molar absorbance coefficients

Abstract

The molar absorbance coefficients of metallic, semiconducting, and (6,5) chirality enriched single-wall carbon nanotubes were evaluated by a spray technique combined with atomic force microscopy. Single-wall carbon nanotubes with isolated and a single predominant electronic type were obtained by using the density-gradient ultracentrifugation technique. In the visible region, all coefficients had similar values around 2-5 × 109/mL mol-1cm-1, independent of their diameter distribution and the electronic types of single-wall carbon nanotubes, and the εS22/εM11 and εS11/εM11 were estimated to be 1.0 and 4.0, respectively.The coefficient strongly depends on the length of single-wall carbon nanotubes, independent of their electronic types and chirality.