Synthesis of carbon nanosheets and carbon nanotubes by radio frequency plasma enhanced chemical vapor deposition

Carbon nanosheets are a two-dimensional carbon nanostructure consisting of free-standing graphite sheets (similar to 1 nm thick) which we deposit using an inductively coupled RF PECVD method. Our previous reports have shown that carbon nanosheets can be grown on a variety of substrates, without catalyst, and under various growth conditions. In this work we describe process details and plasma control parameters to permit rapid changeover from nanotube to nanosheet deposition in the same system. We present a thorough characterization of the nanosheet layer that is produced under these circumstances. We also propose plausible mechanisms to account for the different mode of layer growth leading to the observed topography and conformation of the nanosheets. The experimental evidence suggests that a combination of high plasma electron density and large atomic hydrogen density of the inductively coupled plasma is the reason for nanosheet formation. (c) 2006 Elsevier B.V. All rights reserved.