Research output: Contribution to journal › Article › peer-review
Catalyst-free growth of nanocrystalline carbon films on silicon substrates under direct current glow discharge in a mixture of hydrogen and methane was studied by scanning and transmission electron microscopy, Raman spectroscopy, as well as X-ray photoelectron and near edge X-ray absorption fine structure spectroscopy (BESSY II, Berlin). The in-time development of the film structure on a carbided silicon substrate includes the formation of diamond-like particles, ultra-thin graphite flakes parallel to the surface, carbon nanowalls nucleated on the stacked flakes and their growth accompanied by a permanent decrease of the structural defect density, and finally nanotube nucleation at the nanowall edges. Based on the observation of the carbon nanotube/nanowall linear size variation in time and using the calculated binding energies and the diffusion thresholds obtained from the literature, we propose that direct attachment of the CH 3 radicals to the carbon nanowall edge is the predominant mechanism and the rate-limiting step of its growth, whereas carbon nanotube growth is controlled by radicals diffusing along its outer surface.
Original language | English |
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Pages (from-to) | 1477-1487 |
Number of pages | 11 |
Journal | Carbon |
Volume | 50 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2012 |
ID: 35364689