  Nitrogen doped single wall carbon nanotubes have many functional benefits.
Doping opens the possibility to control the electronic energy levels, surface
energy, surface reactivity and charge carrier density. The additional electron
in the outer shell changes the electronic properties of the nanotubes when
introduced into the carbon lattice. Here we present the latest findings in the
in-situ doping during synthesis of single wall carbon nanotubes using caffeine
as a precursor of both carbon and nitrogen. A special furnace with two heating
elements allowed us to sublimate and decompose the solid precursor. Caffeine
allowed us to reach a high doping percentage with high quality nanotubes
directly in a one-step synthesis procedure.
