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