Comparison of carbon nanotube forest growth using AlSi, TiSiN, and TiN as conductive catalyst supports

We evaluate carbon nanotube growth by employing AlSi, TiSiN and TiN as conductive catalyst supports. Using a wide range of chemical vapour deposition conditions, we find that only AlSi and TiSiN yield homogeneously-sized nanoparticles, which are stable throughout both catalyst preparation and nanotube synthesis processes. This favours the growth of forests with area densities of the order of 10¹² nanotubes cm^-2. TiN, in contrast, yield lower density forests in a very narrow window process. The forests and the three screened catalyst supports show ohmic conductivity. TiSiN, however, is the only conductor that leads to the very robust growth process. This suggests TiSiN is useful for applications requiring forest growth on conductors and thus warrants further assessment for reducing nanotube diameter and improving area density of the forests.