Well-Aligned Carbon Nanotubes From Methane/Nitrogen Plasma

Well-aligned carbon nanotubes (CNTs) were grown by microwave plasma-enhanced chemical vapor deposition using N2 as the carrier gases and CH4 as the carbon source. Iron films with different thicknesses on silicon substrates acted as catalysts. The growth and field emission properties of the CNTs were studied as functions of the iron catalyst film thickness and the CH4:N2 ratio. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) were used to study morphologies of the CNT films and the relationship between the iron film thickness and size of the iron clusters formed after the plasma treatment.