A Piece of Writing of Graphene - Essay Example

?A piece of writing of Graphene What is Graphene? It was Hanns-Peter Boehm who first introduced the term ‘graphene’. This term was created by adding a suffix ‘ene’ to the modified version of the word ‘graphite’. The traits of graphene can very much attractive to the researchers in the field of science, particularly in the field of physics. The term ‘graphene’ has attracted huge attention of people in the field of science and engineering as the Noble Prize in Physics was given to the two scientists of the University of Manchester for their extensive research on Graphene. (Geim; 2009). Graphene is actually a one-atom-thick sheet of the atoms of carbon. The interesting thing about graphene is that it has huge power along with adequate electrical conductivity and elasticity. Graphene is actually a significantly huge aromatic molecule. Graphite can get its crystalline form by combining a number of sheets of graphene together. Graphene is regarded as the most fundamental structural component of a few carbon allotropes. For example, graphene lays the basis of graphite, fullerenes, charcoal, etc. The discovery of graphene has immense significance as various new possibilities of research in the area of physics have opened up. Researches in graphene have also helped in opening up huge scopes of its application in high-tech fields. Graphene is considered to be one of the most potential and adaptable components that have ever discovered in the area of physics. (Geim; 2009; Sakamoto 2009). The production of Graphene: Graphene can be separated from graphite as an isolated plane of carbon atoms. People now know that a minute portion of graphene sheet can be produced by abrading graphite. For example, one can get a tiny piece of graphene sheet when one draws a line on paper with a pencil. (Geim; 2009). During the year of 2008, the production of graphene used to be done by exfoliation. This graphene produced through such exfoliation was considered to be one of the most costly components in this world as this component which so small that can be placed on a tiny portion of the cross section of human hair did costs around as much as $1000 in 2008. Since, 2008, the process of exfoliation has been increased and various companies are now selling graphene in huge amount. Researchers have also discovered cheaper version of graphene (Segal, 2009). For example, Korean researchers have produced cheap graphene through the process of transfer of nickel. Graphene can, in fact, be produced by employing different types of methods. Some of the production processes of graphene are listed below: Producing Graphene through Drawing Method: The drawing method is actually a modified version of exfoliation method. Earlier, in this method, a solid tape was used to repetitively divide crystals of graphite into more thin prices to form graphene. The extremely thin flakes of Graphene then used to be dissolved in liquid acetone and after a few steps they were to be sedimented. Over time, the technique of drawing graphene from graphite has been simplified. Particularly, major modification has been done in the step of disposition. Instead of making graphene floating in acetone, the scientists have started to use the method of dry disposition of flakes. (Geim and Novoselov, 2007) Production through heating silicon carbide: Another popular process of producing graphene is heating silicon carbide at a high temperature in order to reduce it to graphene. In this process silicon carbide is heated at more that 1100 degree centigrade. In this method, the dimension of the graphene produced depends on the dimension of the silicon wafer. The face of the silicon wafer which is utilized for the formation of graphene, has significant capacity to influence the density and the level of mobility of graphene. If graphene is produced using this method, then a number of properties of graphene can clearly be visualized. For example, in the graphene produced through heating silicon carbide a kind of feeble anti-localization of the component can be observed, an electronic band-structure can be identified, a high level of mobility independent of temperature can be visualized. Graphene produced through heating silicon carbide is generally known to be as SiC Epitaxial graphene. (Meyer, 2007) Epitaxial graphene produced through metal substrate Under this procedure, an atomic flake of a metal wafer is used to start the process of growth of the epitaxial growth of graphene. The graphene layers produced through this method do not show uniform thickness throughout the layers. In this case, the properties of the upper layers are affected by the type of bonding between the lowest graphene layer and the metal wafer. Generally, the thickness of the layers vary significantly is graphene is produced on the wafer of ruthenium. On the other hand, graphene layers produced on the substrate of iridium are of uniform thickness and do reveal a kind of weak bond. A very interesting thing can be found out at the time of producing graphene layers on copper substrate. In this case, the production of graphene gets automatically stopped after the formation of a single layer of graphene and this single layer can be used to create significantly large films of graphene. (Sutter, 2009). Production of graphene through reduction of graphite oxide: It is considered to be the first method that was applied to produce graphene in the history of graphene. In this case, exfoliation of graphite oxide can be done through fast heating that in turn results in the production of largely dispersed power of carbon with relatively lower percentage of flakes of graphene. (Meyer, 2007) Growth of graphene using melts of metal-carbon: Under this procedure, atoms of carbon are dissolved in a metal melt transition using a particular temperature. Thereafter, the dissolved carbon is used to participate in the formation of a single graphene layer at a lower temperature. In this process, the metal is first gone through the melting process by making a contact to a source of carbon. This carbon source can be power of graphite or chunk of graphite, etc. placing the melted metal in contact with a carbon source at a specific temperature helps in the process of saturation of the atoms of carbon. Then, at a lower temperature, the solubility of the saturated carbon atoms gets decreased and the excess carbon atom will be observed at the top of the metal melt. On the floating layer of melt, different morphologies of graphene are formed, like FLG (Few Layer Graphene), SLG (Single Layer Graphene), etc. (Amini et al. 2010; Gall et al.1997) Application of Graphene: The researchers and engineers have already discovered several uses of graphene. Some of the well recognized and popular applications of graphene are as follows: Data storage: Grahene has been started to be used in super-dense storage of data. A team of researchers of Rice University has invested in 2008 a completely new kind of storage memory that is graphene-based. This kind of graphene-based storage technology is more intense than the existing technologies of storage. (Carmody, 2010). Storage of energy: The use of graphene in the process of energy storage has also become popular. Graphene Energy of Taxas uses of graphene for creating ultra store house of energy that is capable of transmitting electrical power. A number of engineering firms which are presently using nanotubes of carbon to generate wearable electronic devices, are increasingly switching to graphene based storage system of energy as graphene is less thick and less costly to produce. (Carmody, 2010). Production of Optical devices like solar cells: Graphene are strong, adaptable, and sensitive to light. All these properties of graphene has made it capable of improving the competence of solar cells and LEDs. The graphene is also useful in the production of next-level high-tech electronic devices like stretchy touchscreens, superfast laser, etc. (Carmody, 2010). Graphene transistors: Graphene has a high level of electronic quality and because of that scientists and researchers have become attracted to it and started to use it an interesting and efficient way of designing ballistic transistors. Graphene also reveals a desired property of being an ideal element of integrated circuits. Graphene possesses a high level of mobility along with lower noise quality that allows it to be utilized as a desirable channel in a field-effect transistors. Since it is quite a difficult task to produce single layer graphite using a proper metal substrate, the technologists are trying to find out different methods of transferring a single layered sheet of graphene produced by some kind of exfoliation on the top of a target metal wafer. (Berger, 2004; Moon, 2009).). Production of graphene nanaoribbons: Graphene nanaoribbons that is commonly known as GNR is nothing but a single layer of graphene that is cut into a specific shape for providing it with some crucial electrical features. The graphene nanaoribbons possess two-dimensional structure. Their two-dimensional structure along with high thermal and electrical conductivity and capability of producing low noise have made GNRs a potential substitute to copper for interconnects in integrated circuits. In order to increase the capacity of GNRs, the researchers are trying to reduce the energy gaps along the ribbon by changing the width of the ribbons. (Jiao et al. 2009) References: 1. Amini,S., Garay, J., Liu, G., Balandin, A. A. and Abbaschian, R. (2010). "Growth of Large-Area Graphene Films from Metal-Carbon Melts". Journal of Applied Physics 108 (9): 094321. 2. Jiao, L., Zhang, L., Wang, X., Diankov, G. & Hongjie Dai (2009). "Narrow graphene nanoribbons from carbon nanotubes". Nature 458 (7240): 877 3. Meyer, J. (2007). "The structure of suspended graphene sheets". Nature 446 (7131): 60–63 4. Sutter, P. (2009). "Epitaxial graphene: How silicon leaves the scene". Nature Materials 8 (3): 171. 5. Gall,N.R.; Rut’kov, E.V.; Tontegode, A.Y. (1997). "Two Dimensional Graphite Films on Metals and Their Intercalation". International Journal of Modern Physics B 11 (16): 1865–1911 6. Segal, M.(2009). "Selling graphene by the ton". Nature Nanotechnology 4 (10): 612. 7. Geim A. (2009). "Graphene: Status and Prospects". Science 324 (5934): 1530. 8. Sakamoto J. (2009). "Two-Dimensional Polymers: Just a Dream of Synthetic Chemists?". Angew. Chem. Int. Ed. 48 (6): 1030 9. Geim, A. K. and Novoselov, K. S. (2007). "The rise of graphene". Nature Materials 6 (3): 183–191. 10. Berger, C. (2004). "Ultrathin epitaxial graphite: 2D electron gas properties and a route toward graphene-based nanoelectronics". Journal of Physical Chemistry B 108 (52): 19912–19916 11. Carmody, T. (2010). Why Graphene Won Scientists the Nobel Prize. Available at: http://www.wired.com/gadgetlab/2010/10/graphene/ [accessed on 21st June, 2011]. 12. Moon, J.S. (2009). "Epitaxial-Graphene RF Field-Effect Transistors on Si-Face 6H-SiC Substrates". IEEE Electron Device Letters 30 (6): 650–652 Read More