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Graphene was directly grown on r-plane (1-102), c-plane (0001), and a-plane (11-20) sapphires by low pressure chemical vapor deposition without the use of a metal catalyst. The growth temperature was systematically changed between 1090 and 1210 °C to investigate the effects of the crystal orientation of sapphire on the graphene growth. It was found that the growth rate of graphene on r-plane sapphire was very fast compared to that of the samples grown on other orientations. The surface catalytic effect of r-plane sapphire promotes the smooth and flat growth of single-layer graphene. The surface of the r-plane sapphire was kept smooth even at a high temperature of 1210 °C because a quick coverage of graphene protects the surface of the sapphire from thermal decomposition and roughening.

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Growth of single-walled carbon nanotubes (SWNTs) was carried out on SiO 2 /Si substrates at 700 C with Pt catalysts using an alcohol gas source method in a high vacuum. Scanning electron microscopy observations and Raman spectroscopy measurements showed the optimal ethanol pressure to be 1 × 10 −4 Pa, which was much smaller than that used in the SWNT growth with a Co catalyst. Raman spectra measured with various excitation wavelengths showed that the G/Si ratios of the SWNTs grown with the Pt catalyst at 1 × 10 −4 Pa was fairly larger than those grown with the Co catalyst at 1 × 10 −1 Pa, indicating that the SWNT yield of the former was higher than that of the latter, in spite of the lower ethanol pressure. These results indicate that by using the Pt catalyst, the optimal ethanol pressure was considerably reduced, compared to the conventional Co catalyst. The usefulness of Pt catalyst for SWNT growth under low pressure was demonstrated for the first time.