Ni-catalysed carbon nanotubes and nanofibers assemblies grown on TiN/Si(1 0 0) substrates using hot-filaments combined with d.c. plasma CVD

Different carbon nanotubes or nanofibers (CNTs or CNFs) assemblies were obtained using Ni catalyst deposited by Pulsed Laser Deposition (PLD) on TiN/Si(1 0 0) substrate from a H2/C2H2 mixture using plasma emerging from triode configured electrodes with two pairs of intercalated incandescent filaments at 1 kPa and 700 °C. In the presence of a relative intense plasma (54 W power), a dense CNT carpet was grown. The TEM images revealed the presence of elongated yet contorted 10–15 nm diameter CNTs with encapsulated Ni particles at their tips. Using a low plasma power (8 W) in similar conditions and from the same catalyst, a different morphology resulted: few self-sustained long fibrils (diameter around 1 μm) which are curved under the action of their own weight containing compacted CNTs/CNFs and (only in the confined zones near the lateral edges) 50–200  nm thick filaments presenting buds-like structures and Y-shape junctions.

► Dense CNTs carpet was grown by HFdcPECVD on TiN/Si(1 0 0) using Ni catalyst.
► Resulted thin MWCNTs are aligned yet distorted, with Ni nanocatalyst at their tips.
► In the weak plasma, only few micron-size, self-sustained compact fibrils emerges.
► Entangled CNTs/CNFs with Y-junctions emerged in confined zones at the edges.