Graphene

Pieces of a graph given with a mechanical impact on Highly pyrolytic graphite or Kish-graphite. First, thin layers of graphite is placed between the adhesive tape and the rift that has been thin layers of graphite, has not received a thin layer of (among many other films may occur, and single-layer, which are of interest). After otshelushivaniya tape with thin films of graphite and graph presses to the oxidized silicon substrate. This film is difficult to obtain a certain size and shape of the fixed parts of the substrate (horizontal size of films is usually about 10 microns). Found by using an optical microscope (they are poorly visible with a dielectric thickness of 300 nm) film are preparing for the measurements. Using the atomic force microscope, which determines the actual thickness of a film of graphite (which can vary within the limits of 1 nm for a graph). Using e-lithograph and reactive plasma etching, the form of a film set for electrophysical measurements (Hall magnitotransportnyh bridge for measurements).

Pieces of a graph can also be prepared from graphite, using chemical methods. To begin with microcrystals of graphite exposed to a mixture of sulfuric and hydrochloric acids. Graphite is oxidized, and at the edges of the sample appear carboxyl group of the graph. They turned into chlorides using thionyl chloride. Then under the action oktadetsilamina solutions in tetrahydrofuran, carbon tetrachloride and dichlorethane they are moving in grafenovye layers of thickness 0.54 nm. This chemical method is not the only one, and by changing the organic solvents and chemicals can be obtained nanometer layers of graphite.

Articles described another method for obtaining chemical graph embedded in the polymer matrix. It is worth mentioning another two methods: radio frequency plasma-chemical deposition from the gas phase (eng. PECVD), growth at high pressure and temperature (eng. HPHT). Of these methods, only the latter can be used to obtain large area films.

If the crystal pyrolytic graphite substrate and placed between the electrodes, as shown in, it is possible to ensure that the pieces of graphite from the surface, which may be atomic film thickness under the action of an electric field can move on a substrate of oxidized silicon. To prevent the breakdown (between electrodes applied voltage from 1 to 13 kV) between the electrodes were placed as a thin plate of mica.

There are also several reports, on receipt of a graph, grown on substrates of silicon carbide SiC (0001). Graphite film is formed during thermal decomposition of the surface of the substrate SiC (this method of obtaining the graph is much closer to industrial production), and the quality of grown films depends on the stabilization of the crystal: C-Si-stabilized or stabilized surface - in the first case, higher quality films. In the same group of researchers has shown that, despite the fact that the thickness of the graphite is more than one monolayer, the conductance is involved, only one layer in close proximity to the substrate, since the border SiC-C due to work out the difference between the two materials is formed neskompensirovanny charge. Properties such film properties were equivalent to the graph.