The effects of process parameters on size, density, structure, and field emission properties of Pd-catalyzed carbon nanotubes synthesized by thermal chemical vapor deposition

In this study, various thicknesses of Pd catalytic films were deposited on Ti/Si substrates and pretreated with NH₃. The effects of catalyst deposition parameters and NH₃ pretreatment time (0, 1, and 10 minutes) on the size distribution of Pd catalytic particles, and subsequently, on the diameter and density of synthesized carbon nanotubes (CNTs) were investigated. The CNTs were synthesized by thermal CVD at 750°C using methane (CH₄) as the carbon source, and a mixture of Ar/H₂ (80 vol.%/20 vol.%) as the carrier gas.