Carbon nanotubes films have been studied with SEM and TEM. The studied films were obtained using a two step method: PVD process and CVD process. Strongly defected and curled carbon nanotubes containing Ni nanoparticles formed the film with thickness of about 300–400 nm. Observed carbon nanotubes were of lengths from 100 nm to 300 nm and did not stick to each other.
Polytype instability of SiC epitaxial films was the main focus of attention in the experiment performed since this factor has a decisive influence on graphene growth, which was the second stage of the experiment. Layers deposited in various initial C/Si ratios were analyzed. Our observations indicate that the initial C/Si ratio in epitaxial growth is a crucial parameter determining which polytype will be grown, in particular for cubic (3C) or hexagonal (4H) polytypes. If the initial C/Si ratio was close to its final value, the dominant polytype was 4H. On the other hand, when the initial C/Si ratio was close to zero, 3C became the major polytype in spite of a non favourable growth temperature. The results for graphene growth on an epi-SiC layer and a bulk substrate, in which case the dominant polytype was 4H, are also presented. These results indicate that layers on epitaxial 4H-SiC are thicker, more relaxed and have better quality in comparison with samples on 4H-SiC substrates. Morphology and defects in SiC epilayers were analyzed using Nomarsky optical microscopy, scanning electron microscopy (SEM) and high resolution X-ray diffraction (XRD). Graphene quality was characterized by Raman spectroscopy.