Chiral Structure Determination of Aligned Single-Walled Carbon Nanotubes on Graphite Surface

Chiral structure determination of single-walled carbon nanotube (SWNT), including its handedness and chiral index (<i>n</i>,<i>m</i>), has been regarded as an intractable issue for both fundamental research and practical application. For a given SWNT, the <i>n</i> and <i>m</i> values can be conveniently deduced if an arbitrary two of its three crucial structural parameters, that is, diameter <i>d</i>, chiral angle θ, and electron transition energy <i>E</i>_<i>ii</i>, are obtained. Here, we have demonstrated a novel approach to derive the (<i>n</i>,<i>m</i>) indices from the θ, <i>d</i>, and <i>E</i>_<i>ii</i> of SWNTs. Handedness and θ were quickly measured based on the chirality-dependent alignment of SWNTs on graphite surface. By combining their measured <i>d</i> and <i>E</i>_<i>ii</i>, (<i>n</i>,<i>m</i>) indices of SWNTs can be independently and uniquely identified from the (θ,<i>d</i>) or (θ,<i>E</i>_<i>ii</i>) plots, respectively. This approach offers intense practical merits of high-efficiency, low-cost, and simplicity