Potassium-intercalated single-wall carbon nanotube bundles: Archetypes for semiconductor/metal hybrid systems

The electronic properties of matter are on the nanometer scale strongly influenced by its local environment. The site-dependent electronic properties in composites of semiconducting and metallic matter are at the heart of establishing molecular electronics. Our combined theoretical and experimental investigations comprise first-principles calculations, resonant x-ray absorption as well as core-level and valence-band photoemission on pristine and potassium intercalated bundles of mixtures of semiconducting and metallic single-wall carbon nanotubes. We present a coherent picture of the archetypical changes in the site selective electronic properties of this tunable semiconductor/metal hybrid system.