Limited Number of Possible Mean Diameters in the Evaporation Synthesis of Single-Walled Carbon Nanotubes

Abstract

Diameter dependencies for the pulsed laser evaporation synthesis of single‐walled carbon nanotubes (SWCNT’s) have been studied by optical absorption spectroscopy. Nanotube diameter changes found in our experiments are always very small and depend on a limited number of physical parameters of the synthesis environment and on the catalyst composition. This is in strong contrast to SWCNT synthesized by the decomposition of organic precursors (CVD). From extensive synthesis experiments we find a window for the mean nanotube diameter for the evaporation synthesis that opens at roughly 0.95 nm and closes at roughly 1.55 nm. Possibilities to increase this nanotube diameter window are discussed.