Packing-induced electronic structure changes in bundled single-wall carbon nanotubes

The electronic structure of free-standing parallel and braided bundles of single-wall carbon nanotubes (∼1.2nm diameter) was probed by transmission electron microscopy and electron energy loss spectroscopy. The observed dramatic changes in the carbon K(1s) near-edge structures are attributed to the tubes’ structural packing in bundles which consequently alters their electronic structure. The π*- and the σ*-states are shown to be strongly affected by the way the tubes are packed in the bundles (i.e., parallel, braided, turned, or twisted).