Density control of carbon nanotubes for field emission display by control of catalytic layer diffusion

In this report, we have controlled the growth of multiwalled carbon nanotubes (MWNT) in terms of the populations and diameters by introducing a buffer layer between catalytic layer and amorphous silicon coated substrates. The carbon nanotubes growth with the chemical vapor deposition technique might produce interaction of the metallic catalyst with silicon layer, which could interrupt the catalytic effect. We will show how control of diffusion layer between the amorphous silicon and metal catalyst effectively control the formation of the silicide phase and consequently optimize the carbon nanotubes growth. It is performed on amorphous silicon coated glass by infrared radiation heated thermal chemical vapor deposition(CVD), using a gas mixture of carbon mono-oxide and hydrogen and Fe-Ni-Co alloy catalyst at temperatures as low as 480∼580°C.