CVD Synthesis of Small-Diameter Single Walled Carbon Nanotubes on   Silicon
  A simple process for chemical vapor deposition of ultra SD single wall carbon nanotubes has been developed. In this process, an iron nitrate nonahydrate solution in isopropyl alcohol with a concentration of 400 ug/mlit was used to catalyze nanoparticles formation on an oxidized silicon wafer. The oxide on the substrate was made of a thick layer of wet oxide sandwiched between tow thin layers of dry oxide. The process results in semiconducting single-walled carbon nanotubes (SWNTs) with diameter of less than 0.7nm and more than 1ev band gap energy, which are amongst the smallest diameters of SWNTs ever reported. 
Nima Arjmandi, Pejhman Sasanpour, Bijan Rashidian
cond-mat.mes-hall cond-mat.mtrl-sci