▎ 摘 要
Graphene and carbon nanotubes (CNT) can be produced by vacuum decomposition of Sic, but discrepancies and conflicting data in the literature limit the use of this method for CNT synthesis. A systematic study of the effects of Sic surface morphology and carbon transport through the gas phase leads to reproducible and controlled growth of arrays of small-diameter (1-4 walls) nanotubes, which show pronounced radial breathing modes in Raman spectra, on either carbon (000 (1) over bar) or silicon (0001) face of 6H Sic wafers at 1400-1900 degrees C. These nanotube arrays have a very high density and are catalyst-free with no internal closures. They show a higher oxidation resistance compared to CNTs produced by catalytic chemical vapor deposition (CVD). Their integration with graphite/graphene or silica layers on Sic wafers is possible in a simple 2-step process and opens new horizons in nanoscale device fabrication. (C) 2008 Elsevier Ltd. All rights reserved.