Spectroscopical investigation of carbon nanostructures

Carbon is the only element in the IV column to have both the sp2 and the sp3 bonding, and this allows it to have an allotropic form. Different carbon nanostructures with a different number of carbon atoms and geometrical shape can obtained.These imply different electronic properties according to the geometrical structures. They are smaller, longer, cleaner, and more chemically manipulable than the semiconducting or metallic counterparts up to now used. Novel photoemission spectroscopy investigations by a synchrotron radiation source have been performed on carbon nanostructures. Core level and valence band of single wall, multiwall, carbon onions have studied. Intercalation by potassium have been performed to observe how the electronic structures can be modified and in detail the Fermi edge. Our data show how a Luttinger liquid behaviour can be observed in the single wall carbon nanotubes,while for the multiwall carbon nanotubes a Fermi liquid behaviour can be assigned. A shift to higher binding energy and broadening of the core level upon the potassium intercalation has been observed as temperature of decomposition of singlewall.