Synthesis of doped carbon nanotubes by CVD using NiB catalysts

We have proposed a new method for in-situ doping of multiwall carbon nanotubes (MWCNTs) by catalytic CVD using nickel boron (NiB) as the catalyst. Raman spectrum measurements were carried out to determine the effects of doping using NiB catalysts with different B-concentrations at different CVD temperatures. The characteristic shifts in the Raman spectra which indicate carrier doping were demonstrated for the NiB catalyst with 18 atomic % B at the CVD temperature of 900°C. The CNT crystallinity was improved by a new catalyst structure with a B-capping layer over the NiB catalyst.