1.02 Carbon Nanotubes: Electronic Structure

alperpendicular to the tube axis, while along the tube axis the elementary excitations are fully delocalized Bloch states. The semiconducting behavior of the nanotubes derives from this quantization and can be considered a new property with respect to graphene having zero gap. devices, for example, the single-tube field effect tran-sistor (FET) devices, which challenge the ultimate limit in miniaturizing. In these FET devices, the photoconductivity of single nanotubes has been stu-died, showing excitonic characteristics [3], an