Sheath-dependent orientation control of carbon nanofibres and carbon nanotubes during plasma-enhanced chemical vapour deposition

The aligned growth of carbon nanofibres (CNFs) and carbon nanotubes (CNTs) via a simple sheath-dependent technique for orientation control Is demonstrated. Significant difference in the alignment behaviour of CNFs/CNTs, involving the transition of sheath-dependent electric fields, is found to depend on the relation between the sheath width and the sample dimension. The electric field within the plasma sheath contributes to the aligned growth of CNFs/CNTs with an absolule orientation, and can be used to direct the assembly of CNFs/CNTs in a predetermined manner relative to the substrate by tilting the sample in a sheath region. The consequent application for synthesis of kinked carbon nanostructures by altering the alignment angle to the substrate during growth is also achieved.