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−1 cm−1, independent of their diameter distribution and the electronic types of single-wall carbon nanotubes, and theεS22/εM11 andεS11/εM11were 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.