Influence of the Electrical Conductivity of the Silicon Substrate on the Growth of Multi-walled Carbon Nanotubes

We introduce the electrical conductivity (σ) of the substrate as a new variable to control the growth of multi-walled carbon nanotubes (MWNTs) fabricated by using thermal chemical vapor deposition (CVD). P-type silicon (100) substrates with three different electrical conductivities were used to evaluate the growth mode of the MWNTs. We found that a strong correlation existed between the morphology, diameter, length, and density, of the MWNTs and the electrical conductivity of the silicon substrate. As σ of the substrate increased, the catalytic iron-particle density was observed to decrease and the average particle size to increase. Based on our experimental results, we suggest that the electrical conductivity of the substrate could be used as a control parameter for the growth of MWNTs by using thermal CVD without altering other growth parameters. We introduce the electrical conductivity (σ) of the substrate as a new variable to control the growth of multi-walled carbon nanotubes (MWNTs) fabricated by using thermal chemical vapor deposition (CVD). P-type silicon (100) substrates with three different electrical conductivities were used to evaluate the growth mode of the MWNTs. We found that a strong correlation existed between the morphology, diameter, length, and density, of the MWNTs and the electrical conductivity of the silicon substrate. As σ of the substrate increased, the catalytic iron-particle density was observed to decrease and the average particle size to increase. Based on our experimental results, we suggest that the electrical conductivity of the substrate could be used as a control parameter for the growth of MWNTs by using thermal CVD without altering other growth parameters. KCI Citation Count: 2