Free-standing subnanometer graphite sheets

Free-standing graphite sheets with thickness less than 1 nm, "carbon nanosheets," were synthesized on a variety of substrates by radio-frequency plasma-enhanced chemical vapor deposition without any catalyst or special substrate treatment. The nanosheets consist of one to three graphene layers with a large smooth surface topography, standing roughly vertical to the substrate. Due to the atomic thickness and corrugated nature of nanosheets, low-energy vibrational modes are present in the Raman spectra. The low turn-on field of 4.7 V/mum for electron field emission suggests that the carbon nanosheets could be used as a potential edge emitter. (C) 2004 American Institute of Physics.