{"171751":{"#nid":"171751","#data":{"type":"news","title":"Fabrication on Patterned Silicon Carbide Produces Bandgap for Graphene-Based Electronics","body":[{"value":"\u003Cp\u003EBy fabricating graphene structures atop nanometer-scale \u201csteps\u201d etched into silicon carbide, researchers have for the first time created a substantial electronic bandgap in the material suitable for room-temperature electronics. Use of nanoscale topography to control the properties of graphene could facilitate fabrication of transistors and other devices, potentially opening the door for developing all-carbon integrated circuits.\u003C\/p\u003E\u003Cp\u003EResearchers have measured a bandgap of approximately 0.5 electron-volts in 1.4-nanometer bent sections of graphene nanoribbons. The development could provide new direction to the field of graphene electronics, which has struggled with the challenge of creating bandgap necessary for operation of electronic devices.\u003C\/p\u003E\u003Cp\u003E\u201cThis is a new way of thinking about how to make high-speed graphene electronics,\u201d said Edward Conrad, a professor in the School of Physics at the Georgia Institute of Technology. \u201cWe can now look seriously at making fast transistors from graphene. And because our process is scalable, if we can make one transistor, we can potentially make millions of them.\u201d\u003C\/p\u003E\u003Cp\u003EThe findings were reported November 18 in the journal \u003Cem\u003ENature Physics\u003C\/em\u003E. The research, done at the Georgia Institute of Technology in Atlanta and at SOLEIL, the French national synchrotron facility, has been supported by the National Science Foundation Materials Research Science and Engineering Center (MRSEC) at Georgia Tech, the W.M. Keck Foundation and the Partner University Fund from the Embassy of France.\u003C\/p\u003E\u003Cp\u003EResearchers don\u2019t yet understand why graphene nanoribbons become semiconducting as they bend to enter tiny steps \u2013 about 20 nanometers deep \u2013 that are cut into the silicon carbide wafers. But the researchers believe that strain induced as the carbon lattice bends, along with the confinement of electrons, may be factors creating the bandgap. The nanoribbons are composed of two layers of graphene.\u003C\/p\u003E\u003Cp\u003EProduction of the semiconducting graphene structures begins with the use of e-beams to cut \u201ctrenches\u201d into silicon carbide wafers, which are normally polished to create a flat surface for the growth of epitaxial graphene. Using a high-temperature furnace, tens of thousands of graphene ribbons are then grown across the steps, using photolithography.\u003C\/p\u003E\u003Cp\u003EDuring the growth, the sharp edges of trenches become smoother as the material attempts to regain its flat surface. The growth time must therefore be carefully controlled to prevent the narrow silicon carbide features from melting too much.\u003C\/p\u003E\u003Cp\u003EThe graphene fabrication also must be controlled along a specific direction so that the carbon atom lattice grows into the steps along the material\u2019s \u201carmchair\u201d direction. \u201cIt\u2019s like trying to bend a length of chain-link fence,\u201d Conrad explained. \u201cIt only wants to bend one way.\u201d\u003C\/p\u003E\u003Cp\u003EThe new technique permits not only the creation of a bandgap in the material, but potentially also the fabrication of entire integrated circuits from graphene without the need for interfaces that introduce resistance. On either side of the semiconducting section of the graphene, the nanoribbons retain their metallic properties.\u003C\/p\u003E\u003Cp\u003E\u201cWe can make thousands of these trenches, and we can make them anywhere we want on the wafer,\u201d said Conrad. \u201cThis is more than just semiconducting graphene. The material at the bends is semiconducting, and it\u2019s attached to graphene continuously on both sides. It\u2019s basically a Shottky barrier junction.\u201d\u003C\/p\u003E\u003Cp\u003EBy growing the graphene down one edge of the trench and then up the other side, the researchers could in theory produce two connected Shottky barriers \u2013 a fundamental component of semiconductor devices. Conrad and his colleagues are now working to fabricate transistors based on their discovery.\u003C\/p\u003E\u003Cp\u003EConfirmation of the bandgap came from angle-resolved photoemission spectroscopy measurements made at the Synchrotron CNRS in France. There, the researchers fired powerful photon beams into arrays of the graphene nanoribbons and measured the electrons emitted.\u003C\/p\u003E\u003Cp\u003E\u201cYou can measure the energy of the electrons that come out, and you can measure the direction from which they come out,\u201d said Conrad. \u201cFrom that information, you can work backward to get information about the electronic structure of the nanoribbons.\u201d\u003C\/p\u003E\u003Cp\u003ETheorists had predicted that bending graphene would create a bandgap in the material. But the bandgap measured by the research team was larger than what had been predicted.\u003C\/p\u003E\u003Cp\u003EBeyond building transistors and other devices, in future work the researchers will attempt to learn more about what creates the bandgap \u2013 and how to control it. The property may be controlled by the angle of the bend in the graphene nanoribbon, which can be controlled by altering the depth of the step.\u003C\/p\u003E\u003Cp\u003E\u201cIf you try to lay a carpet over a small imperfection in the floor, the carpet will go over it and you may not even know the imperfection is there,\u201d Conrad explained. \u201cBut if you go over a step, you can tell. There are probably a range of heights in which we can affect the bend.\u201d\u003C\/p\u003E\u003Cp\u003EHe predicts that the discovery will create new activity as other graphene researchers attempt to utilize the results.\u003C\/p\u003E\u003Cp\u003E\u201cIf you can demonstrate a fast device, a lot of people will be interested in this,\u201d Conrad said. \u201cIf this works on a large scale, it could launch a niche market for high-speed, high-powered electronic devices.\u201d\u003C\/p\u003E\u003Cp\u003EIn addition to Conrad, the research team included J. Hicks, M.S. Nevius, F. Wang, K. Shepperd, J. Palmer, J. Kunc, W.A. De Heer and C. Berger, all from Georgia Tech; A. Tejeda from the Institut Jean Lamour, CNES \u2013 Univ. de Nancy and the Synchrotron SOLEIL; A. Taleb-Ibrahimi from the CNRS\/Synchrotron SOLEIL, and F. Bertran and P. Le Fevre from Synchrotron SOLEIL.\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThis research was supported by the National Science Foundation Materials Research Science and Engineering Center (MRSEC) at Georgia Tech under Grants DMR-0820382 and DMR-1005880, the W.M. Keck Foundation, and the Partner University Fund from the Embassy of France. The content of the article is the responsibility of the authors and does not necessarily represent the views of the National Science Foundation.\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECITATION\u003C\/strong\u003E: Hicks, J., A wide-bandgap metal-semiconductor-metal nanostructure made entirely from graphene, Nature Physics (2012). \u003Ca href=\u0022http:\/\/dx.doi.org\/10.1038\/NPHYS2487\u0022 title=\u0022http:\/\/dx.doi.org\/10.1038\/NPHYS2487\u0022\u003Ehttp:\/\/dx.doi.org\/10.1038\/NPHYS2487\u003C\/a\u003E.\u003Cbr \/\u003E\u003Cbr \/\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003EGeorgia Institute of Technology\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003E177 North Avenue\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003EAtlanta, Georgia\u0026nbsp; 30332-0181\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cbr \/\u003E\u003Cstrong\u003EMedia Relations Contact\u003C\/strong\u003E: John Toon (404-894-6986)(\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E)\u003Cbr \/\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: John Toon\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EBy fabricating graphene structures atop nanometer-scale \u201csteps\u201d etched into silicon carbide, researchers have for the first time created a substantial electronic bandgap in the material suitable for room-temperature electronics. Use of nanoscale topography to control the properties of graphene could facilitate fabrication of transistors and other devices, potentially opening the door for developing all-carbon integrated circuits.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Researchers have created a substantial electronic bandgap in graphene suitable for room-temperature electronics."}],"uid":"27303","created_gmt":"2012-11-16 18:31:03","changed_gmt":"2016-10-08 03:13:14","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2012-11-18T00:00:00-05:00","iso_date":"2012-11-18T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"hg_media":{"171721":{"id":"171721","type":"image","title":"Graphene bandgap","body":null,"created":"1449178999","gmt_created":"2015-12-03 21:43:19","changed":"1475894811","gmt_changed":"2016-10-08 02:46:51","alt":"Graphene bandgap","file":{"fid":"195736","name":"graphene-bandgap.jpg","image_path":"\/sites\/default\/files\/images\/graphene-bandgap_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/graphene-bandgap_0.jpg","mime":"image\/jpeg","size":178253,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/graphene-bandgap_0.jpg?itok=xxsj8w34"}},"171731":{"id":"171731","type":"image","title":"Graphene bandgap2","body":null,"created":"1449178999","gmt_created":"2015-12-03 21:43:19","changed":"1475894811","gmt_changed":"2016-10-08 02:46:51","alt":"Graphene bandgap2","file":{"fid":"195737","name":"graphene-bandgap2.jpg","image_path":"\/sites\/default\/files\/images\/graphene-bandgap2_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/graphene-bandgap2_0.jpg","mime":"image\/jpeg","size":205398,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/graphene-bandgap2_0.jpg?itok=z6QTpK_1"}},"171741":{"id":"171741","type":"image","title":"Graphene bandgap3","body":null,"created":"1449178999","gmt_created":"2015-12-03 21:43:19","changed":"1475894811","gmt_changed":"2016-10-08 02:46:51","alt":"Graphene bandgap3","file":{"fid":"195738","name":"graphene-bandgap3.jpg","image_path":"\/sites\/default\/files\/images\/graphene-bandgap3_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/graphene-bandgap3_0.jpg","mime":"image\/jpeg","size":144655,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/graphene-bandgap3_0.jpg?itok=voS-G2G3"}}},"media_ids":["171721","171731","171741"],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"50751","name":"bandgap"},{"id":"50761","name":"Ed Conrad"},{"id":"9116","name":"epitaxial graphene"},{"id":"429","name":"graphene"},{"id":"432","name":"nanoribbon"},{"id":"166937","name":"School of Physics"},{"id":"169534","name":"silicon carbide"}],"core_research_areas":[{"id":"39451","name":"Electronics and Nanotechnology"},{"id":"39471","name":"Materials"}],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EJohn Toon\u003C\/p\u003E\u003Cp\u003EResearch News \u0026amp; Publications Office\u003C\/p\u003E\u003Cp\u003E(404) 894-6986\u003C\/p\u003E\u003Cp\u003E\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}},"70182":{"#nid":"70182","#data":{"type":"news","title":"Controlling Silicon Evaporation Improves Quality of Graphene","body":[{"value":"\u003Cp\u003EScientists from the Georgia Institute of Technology have for the first time provided details of their \u0022confinement controlled sublimation\u0022 technique for growing high-quality layers of epitaxial graphene on silicon carbide wafers.  The technique relies on controlling the vapor pressure of gas-phase silicon in the high-temperature furnace used for fabricating the material.\u003C\/p\u003E\n\u003Cp\u003EThe basic principle for growing thin layers of graphene on silicon carbide requires heating the material to about 1,500 degrees Celsius under high vacuum.  The heat drives off the silicon, leaving behind one or more layers of graphene.  But uncontrolled evaporation of silicon can produce poor quality material useless to designers of electronic devices.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022For growing high-quality graphene on silicon carbide, controlling the evaporation of silicon at just the right temperature is essential,\u0022 said Walt de Heer, a professor who pioneered the technique in the Georgia Tech School of Physics.  \u0022By precisely controlling the rate at which silicon comes off the wafer, we can control the rate at which graphene is produced.  That allows us to produce very nice layers of epitaxial graphene.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EDe Heer and his team begin by placing a silicon carbide wafer into an enclosure made of graphite.  A small hole in the container controls the escape of silicon atoms as the one-square-centimeter wafer is heated, maintaining the rate of silicon evaporation and condensation near its thermal equilibrium.  The growth of epitaxial graphene can be done in a vacuum or in the presence of an inert gas such as argon, and can be used to produce both single layers and multiple layers of the material.  \n\u003C\/p\u003E\n\u003Cp\u003E\u0022This technique seems to be completely in line with what people might one day do in fabrication facilities,\u0022 de Heer said. \u0022We believe this is quite significant in allowing us to rationally and reproducibly grow graphene on silicon carbide. We feel we now understand the process, and believe it could be scaled up for electronics manufacturing.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EThe technique for growing large-area layers of epitaxial graphene was described this week in the Early Edition of the journal \u003Cem\u003EProceedings of the National Academy of Sciences\u003C\/em\u003E.  The research has been supported by the National Science Foundation through the Georgia Tech Materials Research Science and Engineering Center (MRSEC), the Air Force Office of Scientific Research, and the W.M. Keck Foundation.\n\u003C\/p\u003E\n\u003Cp\u003EThe paper also describes a technique for growing narrow graphene ribbons, a process de Heer\u0027s group has called \u0022templated growth.\u0022  That technique, which could be useful for making graphene interconnects, was first described in October 2010 in the journal \u003Cem\u003ENature Nanotechnology\u003C\/em\u003E.\n\u003C\/p\u003E\n\u003Cp\u003EThe templated growth technique involves etching patterns into silicon carbide surfaces using conventional nanolithography processes.  The patterns serve as templates directing the growth of graphene structures on portions of the patterned surfaces.  The technique forms nanoribbons of specific widths without the use of electron beams or other destructive cutting techniques.  Graphene nanoribbons produced with these templates have smooth edges that avoid problems with electron scattering.\n\u003C\/p\u003E\n\u003Cp\u003ETogether, the two techniques provide researchers with the flexibility to produce graphene in forms appropriate to different needs, de Heer noted.  Large-area sheets of graphene may be grown on both the carbon-terminated and silicon-terminated sides of a silicon carbide wafer, while the narrow ribbons may be grown on the silicon-terminated side.  Because of different processing techniques, only one side of a particular wafer can be used.  \n\u003C\/p\u003E\n\u003Cp\u003EThe Georgia Tech research team -- which includes Claire Berger, Ming Ruan, Mike Sprinkle, Xuebin Li, Yike Hu, Baiqian Zhang, John Hankinson and Edward Conrad -- has so far fabricated structures as narrow as 10 nanometers using the templated growth technique.  These nanowires exhibit interesting quantum transport properties.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022We can make very good quantum wires using the templated growth technique,\u0022 de Heer said. \u0022We can make large structures and devices that demonstrate the Quantum Hall Effect, which is important for many applications.  We have demonstrated that templated growth can go all the way down to the nanoscale, and that the properties get even better there.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EDevelopment of the sublimation technique arose from efforts to protect the growing graphene from oxygen and other contaminants in the furnace.  To address the quality concerns, the research team tried enclosing the wafer in a graphite container from which some silicon gas was permitted to leak out.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022We soon realized that graphene grown in the container was much better than what we had been producing,\u0022 de Heer recalled. \u0022Originally, we thought it was because we were protecting it from contaminants.  Later, we realized it was because we were controlling the evaporation of silicon.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EEpitaxial graphene may be the basis for a new generation of high-performance devices that will take advantage of the material\u0027s unique properties in applications where higher costs can be justified.  Silicon, today\u0027s electronic material of choice, will continue to be used in applications where high-performance is not required, de Heer said.\n\u003C\/p\u003E\n\u003Cp\u003EThough researchers are still struggling to design nanometer-scale epitaxial graphene devices that take advantage of the material\u0027s unique properties, de Heer is confident that will ultimately be done.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022These techniques allow us to make accurate nanostructures and seem to be very promising for making the nanoscale devices that we need,\u0022 he said. \u0022While there are serious challenges ahead for using graphene in electronics, we have overcome roadblocks before.\u0022\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\nGeorgia Institute of Technology\u003Cbr \/\u003E\n75 Fifth Street, N.W., Suite 314\u003Cbr \/\u003E\nAtlanta, Georgia  30308  USA\n\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003E\n\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts\u003C\/strong\u003E: John Toon (404-894-6986)(\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E) or Abby Robinson (404-385-3364)(\u003Ca href=\u0022mailto:abby@innovate.gatech.edu\u0022\u003Eabby@innovate.gatech.edu\u003C\/a\u003E).\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: John Toon\n\u003C\/p\u003E\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EGeorgia Tech scientists have for the first time provided details of their \u0022confinement controlled sublimation\u0022 technique for growing high-quality layers of epitaxial graphene on silicon carbide wafers.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Scientists reveal details of their graphene fabrication process."}],"uid":"27303","created_gmt":"2011-09-22 00:00:00","changed_gmt":"2016-10-08 03:10:14","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2011-09-22T00:00:00-04:00","iso_date":"2011-09-22T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"70183":{"id":"70183","type":"image","title":"Researchers with graphene furnace","body":null,"created":"1449177304","gmt_created":"2015-12-03 21:15:04","changed":"1475894616","gmt_changed":"2016-10-08 02:43:36"},"70184":{"id":"70184","type":"image","title":"Graphene furnace","body":null,"created":"1449177304","gmt_created":"2015-12-03 21:15:04","changed":"1475894616","gmt_changed":"2016-10-08 02:43:36"}},"media_ids":["70183","70184"],"related_links":[{"url":"http:\/\/www.physics.gatech.edu\/","title":"Georgia Tech School of Physics"},{"url":"http:\/\/www.mrsec.gatech.edu\/","title":"Materials Research Science and Engineering Center"},{"url":"http:\/\/www.graphene.gatech.edu\/","title":"Epitaxial Graphene Lab"},{"url":"https:\/\/www.physics.gatech.edu\/user\/walter-de-heer","title":"Walt de Heer"}],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"145","name":"Engineering"},{"id":"149","name":"Nanotechnology and Nanoscience"},{"id":"135","name":"Research"},{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"10880","name":"epitaxial"},{"id":"14402","name":"furnace"},{"id":"429","name":"graphene"},{"id":"960","name":"physics"},{"id":"169534","name":"silicon carbide"},{"id":"12422","name":"Walt de Heer"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EJohn Toon\u003C\/strong\u003E\u003Cbr \/\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=jt7\u0022\u003EContact John Toon\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-6986\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}},"66351":{"#nid":"66351","#data":{"type":"news","title":"Flower-Like Defects May Help Graphene Respond to Stress","body":[{"value":"\u003Cp\u003EBeyond its ability to conduct electrons almost without resistance, the nanomaterial graphene also has amazing mechanical properties, including high strength that could one day make it useful in lightweight, robust structures.  But this material is not without flaws -- including a family of flower-like defects that could detract from its electronic and mechanical properties. \u003C\/p\u003E\n\u003Cp\u003EIn a paper published in the journal \u003Cem\u003EPhysical Review B\u003C\/em\u003E, researchers at the Georgia Institute of Technology and the National Institute of Standards and Technology (NIST) have described a family of seven potential defect structures that may appear in sheets of graphene and imaged examples of the lowest-energy defect in the family. \n\u003C\/p\u003E\n\u003Cp\u003EThe defects may arise to help relieve mechanical stress in graphene\u0027s carbon-atom honeycomb structure by allowing atoms to spread out and occupy slightly more space.  Such stress may arise during the growth of graphene or by stretching the graphene sheet.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022For an engineer interested in the mechanical properties of graphene to create atom-thick membranes, for instance, it would be very important to understand these kinds of properties, which could give rise to plastic deformation of the material,\u0022 said Phillip First, one of the paper\u0027s co-authors and a professor in the Georgia Tech School of Physics.  \u0022For instance, it may be that these defects are just one part of the kinetic pathway to failure for a strained sheet of graphene.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EFor electronic applications, the defects could deflect electrons and cause backscattering that would increase the resistance of the material -- like a rock in a stream slows the flow of water.\u003Cbr \/\u003E\nHowever, First says improved growth techniques developed since the defect study began may eliminate that concern.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022With the growth techniques that have now been developed using silicon carbide, we typically do not see these defects,\u0022 he noted.  \u0022The defects occur on material that we know to be of a lower quality because of the growth conditions or substrate preparation.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EDefects can appear due to the movement of carbon atoms at high temperatures, explained NIST Fellow Joseph Stroscio.  Rearrangements of graphene that require the least amount of energy involve switching from the standard six-member carbon rings to structures containing either five or seven atoms.  The NIST researchers have discovered that stringing five- and seven-member rings together in closed loops creates a new type of defect or grain boundary loop in the honeycomb lattice.\n\u003C\/p\u003E\n\u003Cp\u003EAccording to NIST researcher Eric Cockayne, the fabrication process plays a big role in creating the defects.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022As the graphene forms under high heat, sections of the lattice can come loose and rotate,\u0022 he said.  \u0022As the graphene cools, these rotated sections link back up with the lattice, but in an irregular way.  It\u0027s almost as if patches of the graphene were cut out with scissors, turned clockwise, and made to fit back into the same place.  Only it really doesn\u0027t fit, which is why we get these flowers.\u0022\n\u003C\/p\u003E\n\u003Cp\u003ESo far, only the flower defect, which is composed of six pairs of five- and seven-atom rings, has been observed.  Modeling of graphene\u0027s atomic structure by the NIST team suggests there might be a veritable bouquet of flower-like configurations.  These configurations -- seven in all -- would each possess its own unique mechanical and electrical properties, Cockayne said.\n\u003C\/p\u003E\n\u003Cp\u003EFirst hopes the team can continue studying the defects, both to learn whether their formation can be controlled and to clarify the role of defects in the material\u0027s mechanical properties.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022Graphene is strong and light, so the mechanical properties are of great interest,\u0022 he noted.  \u0022Understanding just how it rips apart is an interesting question that has important implications.  But even with these defects, graphene is still spectacularly strong.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EGeorgia Tech contributions to this work were funded by the Semiconductor Research Corporation (NRI-INDEX) and by the National Science Foundation through the Georgia Tech Materials Research Science and Engineering Center (MRSEC) under grants DMR-0804908 and DMR-0820382.\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cem\u003EMark Esser of NIST also contributed to this article.\u003C\/em\u003E\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\nGeorgia Institute of Technology\u003Cbr \/\u003E\n75 Fifth Street, N.W., Suite 314\u003Cbr \/\u003E\nAtlanta, Georgia  30308  USA\n\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003E\n\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts\u003C\/strong\u003E: John Toon (404-894-6986)(\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E) or Abby Robinson (404-385-3364)(\u003Ca href=\u0022mailto:abby@innovate.gatech.edu\u0022\u003Eabby@innovate.gatech.edu\u003C\/a\u003E).\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: John Toon\n\u003C\/p\u003E\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EIn a new study, researchers at the Georgia Institute of Technology and the National Institute of Standards and Technology (NIST) have described a family of seven potential defect structures that may appear in sheets of graphene.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Researchers describe family of defects in graphene."}],"uid":"27303","created_gmt":"2011-06-01 00:00:00","changed_gmt":"2016-10-08 03:08:49","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2011-06-01T00:00:00-04:00","iso_date":"2011-06-01T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"66352":{"id":"66352","type":"image","title":"Graphene defect structures","body":null,"created":"1449176931","gmt_created":"2015-12-03 21:08:51","changed":"1475894589","gmt_changed":"2016-10-08 02:43:09"}},"media_ids":["66352"],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"149","name":"Nanotechnology and Nanoscience"},{"id":"135","name":"Research"},{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"2504","name":"conductance"},{"id":"531","name":"defect"},{"id":"429","name":"graphene"},{"id":"9115","name":"MRSEC"},{"id":"13305","name":"Phillip First"},{"id":"960","name":"physics"},{"id":"167229","name":"stress"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EJohn Toon\u003C\/strong\u003E\u003Cbr \/\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=jt7\u0022\u003EContact John Toon\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-6986\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}},"65044":{"#nid":"65044","#data":{"type":"news","title":"Technique Produces Graphene Nanoribbons with Metallic Properties","body":[{"value":"\u003Cp\u003EA new \u0022templated growth\u0022 technique for fabricating nanoribbons of epitaxial graphene has produced structures just 15 to 40 nanometers wide that conduct current with almost no resistance.  These structures could address the challenge of connecting graphene devices made with conventional architectures -- and set the stage for a new generation of devices that take advantage of the quantum properties of electrons.\u003C\/p\u003E\n\u003Cp\u003E\u0022We can now make very narrow, conductive nanoribbons that have quantum ballistic properties,\u0022 said Walt de Heer, a professor in the School of Physics at the Georgia Institute of Technology.  \u0022These narrow ribbons become almost like a perfect metal.  Electrons can move through them without scattering, just like they do in carbon nanotubes.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EDe Heer discussed recent results of this graphene growth process March 21st at the American Physical Society\u2019s March 2011 Meeting in Dallas.  The research was sponsored by the National Science Foundation-supported Materials Research Science and Engineering Center (MRSEC).\n\u003C\/p\u003E\n\u003Cp\u003EFirst reported Oct. 3 in the advance online edition of the journal \u003Cem\u003ENature Nanotechnology\u003C\/em\u003E, the new fabrication technique allows production of epitaxial graphene structures with smooth edges.  Earlier fabrication techniques that used electron beams to cut graphene sheets produced nanoribbon structures with rough edges that scattered electrons, causing interference.  The resulting nanoribbons had properties more like insulators than conductors.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022In our templated growth approach, we have essentially eliminated the edges that take away from the desirable properties of graphene,\u0022 de Heer explained.  \u0022The edges of the epitaxial graphene merge into the silicon carbide, producing properties that are really quite interesting.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EThe templated growth technique begins with etching patterns into the silicon carbide surfaces on which epitaxial graphene is grown.  The patterns serve as templates directing the growth of graphene structures, allowing the formation of nanoribbons and other structures of specific widths and shapes without the use of cutting techniques that produce the rough edges.\n\u003C\/p\u003E\n\u003Cp\u003EIn creating these graphene nanostructures, de Heer and his research team first use conventional microelectronics techniques to etch tiny \u0022steps\u0022  -- or contours -- into a silicon carbide wafer whose surface has been made extremely flat.  They then heat the contoured wafer to approximately 1,500 degrees Celsius, which initiates melting that polishes any rough edges left by the etching process.\n\u003C\/p\u003E\n\u003Cp\u003EEstablished techniques are then used for growing graphene from silicon carbide by driving the silicon atoms from the surface.  Instead of producing a consistent layer of graphene across the entire surface of the wafer, however, the researchers limit the heating time so that graphene grows only on portions of the contours.\n\u003C\/p\u003E\n\u003Cp\u003EThe width of the resulting nanoribbons is proportional to the depth of the contours, providing a mechanism for precisely controlling the nanoribbon structures.  To form complex structures, multiple etching steps can be carried out to create complex templates.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022This technique allows us to avoid the complicated e-beam lithography steps that people have been using to create structures in epitaxial graphene,\u0022 de Heer noted.  \u0022We are seeing very good properties that show these structures can be used for real electronic applications.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003ESince publication of the \u003Cem\u003ENature Nanotechnology\u003C\/em\u003E paper, de Heer\u0027s team has been refining its technique.  \u0022We have taken this to an extreme -- the cleanest and narrowest ribbons we can make,\u0022 he said.  \u0022We expect to be able to do everything we need with the size ribbons that we are able to make right now, though we probably could reduce the width to 10 nanometers or less.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EWhile the Georgia Tech team is continuing to develop high-frequency transistors -- perhaps even at the terahertz range -- its primary effort now focuses on developing quantum devices, de Heer said.  Such devices were envisioned in the patents Georgia Tech holds on various epitaxial graphene processes.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022This means that the way we will be doing graphene electronics will be different,\u0022 he explained.  \u0022We will not be following the model of using standard field-effect transistors (FETs), but will pursue devices that use ballistic conductors and quantum interference. We are headed straight into using the electron wave effects in graphene.\u0022\n\u003C\/p\u003E\n\u003Cp\u003ETaking advantage of the wave properties will allow electrons to be manipulated with techniques similar to those used by optical engineers.  For instance, switching may be carried out using interference effects -- separating beams of electrons and then recombining them in opposite phases to extinguish the signals.\n\u003C\/p\u003E\n\u003Cp\u003EQuantum devices would be smaller than conventional transistors and operate at lower power.  Because of its ability to transport electrons with virtually no resistance, epitaxial graphene may be the ideal material for such devices, de Heer said.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022Using the quantum properties of electrons rather than the standard charged-particle properties means opening up new ways of looking at electronics,\u0022 he predicted.  \u0022This is probably the way that electronics will evolve, and it appears that graphene is the ideal material for making this transition.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EDe Heer\u0027s research team hopes to demonstrate a rudimentary switch operating on the quantum interference principle within a year.  \n\u003C\/p\u003E\n\u003Cp\u003EEpitaxial graphene may be the basis for a new generation of high-performance devices that will take advantage of the material\u0027s unique properties in applications where higher costs can be justified.  Silicon, today\u0027s electronic material of choice, will continue to be used in applications where high-performance is not required, de Heer said.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022This is an important step in the process,\u0022 he added.  \u0022There are going to be a lot of surprises as we move into these quantum devices and find out how they work.  We have good reason to believe that this can be the basis for a new generation of transistors based on quantum interference.\u0022\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\nGeorgia Institute of Technology\u003Cbr \/\u003E\n75 Fifth Street, N.W., Suite 314\u003Cbr \/\u003E\nAtlanta, Georgia 30308 USA\n\u003C\/strong\u003E\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts\u003C\/strong\u003E: John Toon (404-894-6986)(\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E) or Abby Robinson (404-385-3364)(\u003Ca href=\u0022mailto:abby@innovate.gatech.edu\u0022\u003Eabby@innovate.gatech.edu\u003C\/a\u003E).\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: John Toon\n\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EA new \u0022templated growth\u0022 technique for fabricating nanoribbons of epitaxial graphene has produced structures just 15 to 40 nanometers wide that conduct current with almost no resistance.  These structures could address the challenge of connecting graphene devices.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Researchers have made graphene nanoribbons with metallic properties."}],"uid":"27303","created_gmt":"2011-03-21 00:00:00","changed_gmt":"2016-10-08 03:08:26","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2011-03-21T00:00:00-04:00","iso_date":"2011-03-21T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"65045":{"id":"65045","type":"image","title":"Growing epitaxial graphene","body":null,"created":"1449176783","gmt_created":"2015-12-03 21:06:23","changed":"1475894574","gmt_changed":"2016-10-08 02:42:54","alt":"Growing epitaxial graphene","file":{"fid":"192147","name":"tis35461.jpg","image_path":"\/sites\/default\/files\/images\/tis35461_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/tis35461_0.jpg","mime":"image\/jpeg","size":1731501,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/tis35461_0.jpg?itok=Q2grkYwo"}},"65046":{"id":"65046","type":"image","title":"Prof. Walt de Heer","body":null,"created":"1449176783","gmt_created":"2015-12-03 21:06:23","changed":"1475894574","gmt_changed":"2016-10-08 02:42:54","alt":"Prof. Walt de Heer","file":{"fid":"192148","name":"toh35777.jpg","image_path":"\/sites\/default\/files\/images\/toh35777_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/toh35777_0.jpg","mime":"image\/jpeg","size":1603740,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/toh35777_0.jpg?itok=GCENVzgL"}},"65047":{"id":"65047","type":"image","title":"Growing expitaxial graphene","body":null,"created":"1449176783","gmt_created":"2015-12-03 21:06:23","changed":"1475894574","gmt_changed":"2016-10-08 02:42:54","alt":"Growing expitaxial graphene","file":{"fid":"192149","name":"tfu35461.jpg","image_path":"\/sites\/default\/files\/images\/tfu35461_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/tfu35461_0.jpg","mime":"image\/jpeg","size":65166,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/tfu35461_0.jpg?itok=4hcNTgqa"}}},"media_ids":["65045","65046","65047"],"related_links":[{"url":"http:\/\/www.physics.gatech.edu\/","title":"Georgia Tech School of Physics"},{"url":"http:\/\/www.mrsec.gatech.edu\/","title":"Materials Research Science and Engineering Center"},{"url":"https:\/\/www.physics.gatech.edu\/user\/walter-de-heer","title":"Walt de Heer"}],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"141","name":"Chemistry and Chemical Engineering"},{"id":"145","name":"Engineering"},{"id":"149","name":"Nanotechnology and Nanoscience"},{"id":"135","name":"Research"},{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"10890","name":"conductor"},{"id":"9116","name":"epitaxial graphene"},{"id":"429","name":"graphene"},{"id":"12423","name":"nanoribbons"},{"id":"4827","name":"resistance"},{"id":"12422","name":"Walt de Heer"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EJohn Toon\u003C\/strong\u003E\u003Cbr \/\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=jt7\u0022\u003EContact John Toon\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-6986\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}},"63409":{"#nid":"63409","#data":{"type":"news","title":"Expitaxial Graphene Shows Promise for Replacing Silicon in Electronics","body":[{"value":"\u003Cp\u003EMove over silicon.  There\u0027s a new electronic material in town, and it goes fast.\n\u003C\/p\u003E\n\u003Cp\u003EThat material, the focus of the 2010 Nobel Prize in physics, is graphene -- a fancy name for extremely thin layers of ordinary carbon atoms arranged in a \u0022chicken-wire\u0022 lattice. These layers, sometimes just a single atom thick, conduct electricity with virtually no resistance, very little heat generation -- and less power consumption than silicon.\n\u003C\/p\u003E\n\u003Cp\u003EWith silicon device fabrication approaching its physical limits, many researchers believe graphene can provide a new platform material that would allow the semiconductor industry to continue its march toward ever-smaller and faster electronic devices -- progress described in Moore\u0027s Law. Though graphene will likely never replace silicon for everyday electronic applications, it could take over as the material of choice for high-performance devices. \n\u003C\/p\u003E\n\u003Cp\u003EAnd graphene could ultimately spawn a new generation of devices designed to take advantage of its unique properties. \n\u003C\/p\u003E\n\u003Cp\u003ESince 2001, Georgia Tech has become a world leader in developing epitaxial graphene, a specific type of graphene that can be grown on large wafers and patterned for use in electronics manufacturing. In a recent paper published in the journal \u003Cem\u003ENature Nanotechnology\u003C\/em\u003E, Georgia Tech researchers reported fabricating an array of 10,000 top-gated transistors on a 0.24 square centimeter chip, an achievement believed to be the highest density reported so far in graphene devices. \n\u003C\/p\u003E\n\u003Cp\u003EIn creating that array, they also demonstrated a clever new approach for growing complex graphene patterns on templates etched into silicon carbide. The new technique offered the solution to one of the most difficult issues that had been facing graphene electronics. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022This is a significant step toward electronics manufacturing with graphene,\u0022 said Walt de Heer, a professor in Georgia Tech\u0027s School of Physics who pioneered the development of graphene for high-performance electronics. \u0022This is another step showing that our method of working with epitaxial graphene grown on silicon carbide is the right approach and the one that will probably be used for making graphene electronics.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EUnrolled Carbon Nanotubes\u003C\/strong\u003E \n\u003C\/p\u003E\n\u003Cp\u003EFor de Heer, the story of graphene begins with carbon nanotubes, tiny cylindrical structures considered miraculous when they first began to be studied by scientists in 1991. De Heer was among the researchers excited about the properties of nanotubes, whose unique arrangement of carbon atoms gave them physical and electronic properties that scientists believed could be the foundation for a new generation of electronic devices. \n\u003C\/p\u003E\n\u003Cp\u003ECarbon nanotubes still have attractive properties, but the ability to grow them consistently -- and to incorporate them in high-volume electronics applications -- has so far eluded researchers. De Heer realized before others that carbon nanotubes would probably never be used for high-volume electronic devices. \n\u003C\/p\u003E\n\u003Cp\u003EBut he also realized that the key to the attractive electronic properties of the nanotubes was the lattice created by the carbon atoms. Why not simply grow that lattice on a flat surface, and use fabrication techniques proven in the microelectronics industry to create devices in much the same way as silicon integrated circuits? \n\u003C\/p\u003E\n\u003Cp\u003EBy heating silicon carbide -- a widely-used electronic material -- de Heer and his colleagues were able to drive silicon atoms from the surface, leaving just the carbon lattice in thin layers of graphene large enough to grow the kinds of electronic devices familiar to a generation of electronics designers.\n\u003C\/p\u003E\n\u003Cp\u003EThat process was the basis for a patent filed in 2003, and for initial research support from chip-maker Intel. Since then, de Heer\u0027s group has published dozens of papers and helped spawn other research groups also using epitaxial graphene for electronic devices. Though scientists are still learning about the material, companies such as IBM have launched research programs based on epitaxial graphene, and agencies such as the National Science Foundation (NSF) and Defense Advanced Research Projects Agency (DARPA) have invested in developing the material for future electronics applications. \n\u003C\/p\u003E\n\u003Cp\u003EGeorgia Tech\u0027s work on developing epitaxial graphene for manufacturing electronic devices was recognized in the background paper produced by the Royal Swedish Academy of Sciences as part of the Nobel Prize documentation. \n\u003C\/p\u003E\n\u003Cp\u003EThe race to find commercial applications for graphene is intense, with researchers from the United States, Europe, Japan and Singapore engaged in well-funded efforts. Since awarding of the Nobel to a group from the United Kingdom, the flood of news releases about graphene developments has grown. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022Our epitaxial graphene is now used around the world by many research laboratories,\u0022 de Heer noted. \u0022We are probably at the stage where silicon was in the 1950s. This is the beginning of something that is going to be very large and important.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003ESilicon \u0022Running Out of Gas\u0022\u003C\/strong\u003E \n\u003C\/p\u003E\n\u003Cp\u003EA new electronics material is needed because silicon is running out of miniaturization room. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022Primarily, we\u0027ve gotten the speed increases from silicon by continually shrinking feature sizes and improving interconnect technology,\u0022 said Dennis Hess, director of the National Science Foundation-sponsored Materials Research Science and Engineering Center (MRSEC) established at Georgia Tech to study future electronic materials, starting with epitaxial graphene. \u0022We are at the point where in less than 10 years, we won\u0027t be able to shrink feature sizes any farther because of the physics of the device operation. That means we will either have to change the type of device we make, or change the electronic material we use.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003EIt\u0027s a matter of physics. At the very small size scales needed to create ever more dense device arrays, silicon generates too much resistance to electron flow, creating more heat than can be dissipated and consuming too much power. \n\u003C\/p\u003E\n\u003Cp\u003EGraphene has no such restrictions, and in fact, can provide electron mobility as much as 100 times better than silicon. De Heer believes his group has developed the roadmap for the future of high-performance electronics -- and that it is paved with epitaxial graphene. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022We have basically developed a whole scheme for making electronics out of graphene,\u0022 he said. \u0022We have set down what we believe will be the ground rules for how that will work, and we have the key patents in place.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003ESilicon, of course, has matured over many generations through constant research and improvement. De Heer and Hess agree that silicon will always be around, useful for low-cost consumer products such as iPods, toasters, personal computers and the like. \n\u003C\/p\u003E\n\u003Cp\u003EDe Heer expects graphene to find its niche doing things that couldn\u0027t otherwise be done. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022We\u0027re not trying to do something cheaper or better; we\u0027re going to do things that can\u0027t be done at all with silicon,\u0022 he said. \u0022Making electronic devices as small as a molecule, for instance, cannot be done with silicon, but in principle could be done with graphene. The key question is how to extend Moore\u0027s Law in a post-CMOS world.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003EUnlike the carbon nanotubes he studied in the 1990s, de Heer sees no major problems ahead for the development of epitaxial graphene. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022That graphene is going to be a major player in the electronics of the future is no longer in doubt,\u0022 he said. \u0022We don\u0027t see any real roadblocks ahead. There are no flashing red lights or other signs that seem to say that this won\u0027t work. All of the issues we see relate to improving technical issues, and we know how to do that.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EMaking the Best Graphene\u003C\/strong\u003E \n\u003C\/p\u003E\n\u003Cp\u003ESince beginning the exploration of graphene in 2001, de Heer and his research team have made continuous improvements in the quality of the material they produce, and those improvements have allowed them to demonstrate a number of physical properties -- such as the Quantum Hall Effect -- that verify the unique properties of the material.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022The properties that we see in our epitaxial graphene are similar to what we have calculated for an ideal theoretical sheet of graphene suspended in the air,\u0022 said Claire Berger, a research scientist in the Georgia Tech School of Physics who also has a faculty appointment at the Centre National de la Recherche Scientifique in France. \u0022We see these properties in the electron transport and we see these properties in all kinds of spectroscopy. Everything that is supposed to be occurring in a single sheet of graphene we are seeing in our systems.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003EKey to the material\u0027s future, of course, is the ability to make electronic devices that work consistently. The researchers believe they have almost reached that point. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022All of the properties that epitaxial graphene needs to make it viable for electronic devices have been proven in this material,\u0022 said Ed Conrad, a professor in Georgia Tech\u0027s School of Physics who is also a MRSEC member. \u0022We have shown that we can make macroscopic amounts of this material, and with the devices that are scalable, we have the groundwork that could really make graphene take off.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003EReaching higher and higher device density is also important, along with the ability to control the number of layers of graphene produced. The group has demonstrated that in their multilayer graphene, each layer retains the desired properties. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022Multilayer graphene has different stacking than graphite, the material found in pencils,\u0022 Conrad noted. \u0022In graphite, every layer is rotated 60 degrees and that\u0027s the only way that nature can do it. When we grow graphene on silicon carbide, the layers are rotated 30 degrees. When that happens, the symmetry of the system changes to make the material behave the way we want it to.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EEpitaxial Versus Exfoliated\u003C\/strong\u003E\n\u003C\/p\u003E\n\u003Cp\u003EMuch of the world\u0027s graphene research -- including work leading to the Nobel -- involved the study of exfoliated graphene: layers of the material removed from a block of graphite, originally with tape. While that technique produces high-quality graphene, it\u0027s not clear how that could be scaled up for industrial production. \n\u003C\/p\u003E\n\u003Cp\u003EWhile agreeing that the exfoliated material has produced useful information about graphene properties, de Heer dismisses it as \u0022a science project\u0022 unlikely to have industrial electronics application. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022Electronics companies are not interested in graphene flakes,\u0022 he said. \u0022They need industrial graphene, a material that can be scaled up for high-volume manufacturing. Industry is now getting more and more interested in what we are doing.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003EDe Heer says Georgia Tech\u0027s place in the new graphene world is to focus on electronic applications. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022We are not really trying to compete with these other groups,\u0022 he said. \u0022We are really trying to create a practical electronic material. To do that, we will have to do many things right, including fabricating a scalable material that can be made as large as a wafer. It will have to be uniform and able to be processed using industrial methods.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EResolving Technical Issues\u003C\/strong\u003E \n\u003C\/p\u003E\n\u003Cp\u003EAmong the significant technical issues facing graphene devices has been electron scattering that occurs at the boundaries of nanoribbons. If the edges aren\u0027t perfectly smooth -- as usually happens when the material is cut with electron beams -- the roughness bounces electrons around, creating resistance and interference. \n\u003C\/p\u003E\n\u003Cp\u003ETo address that problem, de Heer and his team recently developed a new \u0022templated growth\u0022 technique for fabricating nanometer-scale graphene devices. The technique involves etching patterns into the silicon carbide surfaces on which epitaxial graphene is grown. The patterns serve as templates directing the growth of graphene structures, allowing the formation of nanoribbons of specific widths without the use of e-beams or other destructive cutting techniques. Graphene nanoribbons produced with these templates have smooth edges that avoid electron-scattering problems. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022Using this approach, we can make very narrow ribbons of interconnected graphene without the rough edges,\u0022 said de Heer. \u0022Anything that can be done to make small structures without having to cut them is going to be useful to the development of graphene electronics because if the edges are too rough, electrons passing through the ribbons scatter against the edges and reduce the desirable properties of graphene.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003EIn nanometer-scale graphene ribbons, quantum confinement makes the material behave as a semiconductor suitable for creation of electronic devices. But in ribbons a micron or so wide, the material acts as a conductor. Controlling the depth of the silicon carbide template allows the researchers to create these different structures simultaneously, using the same growth process. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022The same material can be either a conductor or a semiconductor depending on its shape,\u0022 noted de Heer. \u0022One of the major advantages of graphene electronics is to make the device leads and the semiconducting ribbons from the same material. That\u0027s important to avoid electrical resistance that builds up at junctions between different materials.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003EAfter formation of the nanoribbons, the researchers apply a dielectric material and metal gate to construct field-effect transistors. While successful fabrication of high-quality transistors demonstrates graphene\u0027s viability as an electronic material, de Heer sees them as only the first step in what could be done with the material. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022When we manage to make devices well on the nanoscale, we can then move on to make much smaller and finer structures that will go beyond conventional transistors to open up the possibility for more sophisticated devices that use electrons more like light than particles,\u0022 he said. \u0022If we can factor quantum mechanical features into electronics, that is going to open up a lot of new possibilities.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003ECollaborations with Other Groups\u003C\/strong\u003E \n\u003C\/p\u003E\n\u003Cp\u003EBefore engineers can use epitaxial graphene for the next generation of electronic devices, they will have to understand its unique properties. As part of that process, Georgia Tech researchers are collaborating with scientists at the National Institute of Standards and Technology (NIST). The collaboration has produced new insights into how electrons behave in graphene. \n\u003C\/p\u003E\n\u003Cp\u003EIn a recent paper published in the journal \u003Cem\u003ENature Physics\u003C\/em\u003E, the Georgia Tech-NIST team described for the first time how the orbits of electrons are distributed spatially by magnetic fields applied to layers of epitaxial graphene. They also found that these electron orbits can interact with the substrate on which the graphene is grown, creating energy gaps that affect how electron waves move through the multilayer material. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022The regular pattern of magnetically-induced energy gaps in the graphene surface creates regions where electron transport is not allowed,\u0022 said Phillip N. First, a professor in the Georgia Tech School of Physics and MRSEC member. \u0022Electron waves would have to go around these regions, requiring new patterns of electron wave interference. Understanding this interference would be important for some bi-layer graphene devices that have been proposed.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003EEarlier NIST collaborations led to improved understanding of graphene electron states, and the way in which low temperature and high magnetic fields can affect energy levels. The researchers also demonstrated that atomic-scale moir\u00e9 patterns, an interference pattern that appears when two or more graphene layers are overlaid, can be used to measure how sheets of graphene are stacked. \n\u003C\/p\u003E\n\u003Cp\u003EIn a collaboration with the U.S. Naval Research Laboratory and University of Illinois at Urbana-Champaign, a group of Georgia Tech professors developed a simple and quick one-step process for creating nanowires on graphene oxide. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022We\u0027ve shown that by locally heating insulating graphene oxide, both the flakes and the epitaxial varieties, with an atomic force microscope tip, we can write nanowires with dimensions down to 12 nanometers,\u0022 said Elisa Riedo, an associate professor in the Georgia Tech School of Physics and a MRSEC member. \u0022And we can tune their electronic properties to be up to four orders of magnitude more conductive.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EA New Industrial Revolution?\u003C\/strong\u003E \n\u003C\/p\u003E\n\u003Cp\u003EThough graphene can be grown and fabricated using processes similar to those of silicon, it is not easily compatible with silicon. That means companies adopting it will also have to build new fabrication facilities -- an expensive investment. Consequently, de Heer believes industry will be cautious about moving into a new graphene world. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022Silicon technology is completely entrenched and well developed,\u0022 he admitted. \u0022We can adopt many of the processes of silicon, but we can\u0027t easily integrate ourselves into silicon. Because of that, we really need a major paradigm shift. But for the massive electronics industry, that will not happen easily or gently.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003EHe draws an analogy to steamships and passenger trains at the dawn of the aviation age. At some point, it became apparent that airliners were going to replace both ocean liners and trains in providing first-class passenger service. Though the cost of air travel was higher, passengers were willing to pay a premium for greater speed. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022We are going to see a coexistence of technologies for a while, and how the hybridization of graphene and silicon electronics is going to happen remains up in the air,\u0022 de Heer predicted. \u0022That is going to take decades, though in the next ten years we are probably going to see real commercial devices that involve graphene.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cem\u003E\u003Cstrong\u003EThis article originally appeared in Research Horizons, Georgia Tech\u0027s research magazine.\u003C\/strong\u003E\u003C\/em\u003E\u003Cstrong\u003E\u003C\/strong\u003E\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\nGeorgia Institute of Technology\u003Cbr \/\u003E\n75 Fifth Street, N.W., Suite 314\u003Cbr \/\u003E\nAtlanta, Georgia  30308  USA\n\u003C\/strong\u003E\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts\u003C\/strong\u003E: John Toon (404-894-6986)(\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E) or Abby Vogel Robinson (404-385-3364)(\u003Ca href=\u0022mailto:abby@innovate.gatech.edu\u0022\u003Eabby@innovate.gatech.edu\u003C\/a\u003E).\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: John Toon\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EGeorgia Tech has become a leader in developing epitaxial graphene, a material that can be grown on large wafers and patterned for use in electronics manufacturing. In a recent paper, Georgia Tech researchers reported fabricating an array of 10,000 top-gated transistors on a 0.24 square centimeter chip.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Georgia Tech has become a world leader in epitaxial graphene."}],"uid":"27303","created_gmt":"2011-01-06 01:00:00","changed_gmt":"2016-10-08 03:07:57","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2011-01-06T00:00:00-05:00","iso_date":"2011-01-06T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"hg_media":{"63410":{"id":"63410","type":"image","title":"Producing epitaxial graphene","body":null,"created":"1449176690","gmt_created":"2015-12-03 21:04:50","changed":"1475894557","gmt_changed":"2016-10-08 02:42:37","alt":"Producing epitaxial graphene","file":{"fid":"191816","name":"tbs48688.jpg","image_path":"\/sites\/default\/files\/images\/tbs48688_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/tbs48688_0.jpg","mime":"image\/jpeg","size":1202030,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/tbs48688_0.jpg?itok=V_zWpccS"}},"63411":{"id":"63411","type":"image","title":"Professor Walt de Heer","body":null,"created":"1449176690","gmt_created":"2015-12-03 21:04:50","changed":"1475894557","gmt_changed":"2016-10-08 02:42:37","alt":"Professor Walt de Heer","file":{"fid":"191817","name":"tic48688.jpg","image_path":"\/sites\/default\/files\/images\/tic48688_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/tic48688_0.jpg","mime":"image\/jpeg","size":1245665,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/tic48688_0.jpg?itok=ZOUqWETF"}},"63412":{"id":"63412","type":"image","title":"Researcher Claire Berger","body":null,"created":"1449176690","gmt_created":"2015-12-03 21:04:50","changed":"1475894557","gmt_changed":"2016-10-08 02:42:37","alt":"Researcher Claire Berger","file":{"fid":"191818","name":"tcs48688.jpg","image_path":"\/sites\/default\/files\/images\/tcs48688_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/tcs48688_0.jpg","mime":"image\/jpeg","size":1118539,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/tcs48688_0.jpg?itok=26pfw7Do"}}},"media_ids":["63410","63411","63412"],"related_links":[{"url":"http:\/\/www.mrsec.gatech.edu\/","title":"Materials Research Science and Engineering Center"},{"url":"http:\/\/www.physics.gatech.edu\/","title":"Georgia Tech School of Physics"},{"url":"https:\/\/www.physics.gatech.edu\/user\/walter-de-heer","title":"Walt de Heer"}],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"153","name":"Computer Science\/Information Technology and Security"},{"id":"145","name":"Engineering"},{"id":"149","name":"Nanotechnology and Nanoscience"},{"id":"135","name":"Research"},{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"9826","name":"de Heer"},{"id":"9116","name":"epitaxial graphene"},{"id":"429","name":"graphene"},{"id":"9115","name":"MRSEC"},{"id":"960","name":"physics"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EJohn Toon\u003C\/strong\u003E\u003Cbr \/\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=jt7\u0022\u003EContact John Toon\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-6986\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}},"63213":{"#nid":"63213","#data":{"type":"external_news","title":"Epitaxial Graphene: Designing a New Electronic Material","body":[{"value":"\u003Cp\u003E2010 Industrial Physics Forum presentation at AIP by Walter de Heer, \nGeorgia Tech\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":"","uid":"27387","created_gmt":"2010-12-16 16:03:29","changed_gmt":"2016-10-08 02:24:15","author":"Brian Danin","boilerplate_text":"","field_publication":"","publication":"sfs minor","field_article_url":"","publication_url":"http:\/\/www.aip.org\/industry\/ipf\/2010\/deheer.html","dateline":{"date":"2010-12-16T00:00:00-05:00","iso_date":"2010-12-16T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"groups":[{"id":"60783","name":"MRSEC"}],"categories":[],"keywords":[{"id":"429","name":"graphene"},{"id":"11482","name":"Walt DeHeer"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}},"63022":{"#nid":"63022","#data":{"type":"news","title":"Georgia Tech\u2019s Walt de Heer Awarded Materials Research Society Medal","body":[{"value":"\u003Cp\u003EThe Materials Research Society awarded Walter A. de Heer,\nprofessor of physics at the Georgia Institute of Technology, the MRS Medal at\nits annual fall meeting in Boston today. De Heer was cited by the society for\nhis \u201cpioneering contributions to the science and technology of epitaxial\ngraphene.\u201d The MRS Medal recognizes an exceptional achievement in materials\nresearch in the past ten years. The MRS Medal is awarded for a\nspecific outstanding recent discovery or advancement that has a major impact on\nthe progress of a materials-related field.\u003C\/p\u003E\n\n\n\n\u003Cp\u003E\u201cI am very pleased and encouraged that our research to\ndevelop epi-graphene for electronics is recognized already in this early stage.\nThis will certainly stimulate others to join us in this important endeavor,\u201d\nsaid de Heer. \u003C\/p\u003E\n\n\n\n\u003Cp\u003EDe Heer and his lab at Georgia Tech are known worldwide as\nthe first to conceptualize the use of graphene for electronics, back in 2001.\nCurrently de Heer\u2019s lab is working on developing epitaxial graphene as a\nreplacement for silicon in electronics.\u003C\/p\u003E\n\n\n\n\u003Cp\u003E\u201cBecause epi-graphene may be able to surpass the speed\nlimitations of silicon, while also allowing for less heat to be generated in a\nsmaller chip, we believe that graphene shows great promise in being able to\nreplace silicon in electronics for applications such as ultra-high frequency\nelectronics, where these attributes will be needed most,\u201d said de Heer. \u003C\/p\u003E\n\n\n\n\u003Cp\u003E\u201cWalt de Heer is a\nglobal\u0026nbsp;leader in graphene research, and we congratulate him on this latest\nrecognition of his important work,\u201d said Georgia Tech President G.P. \u201cBud\u201d Peterson.\n\u0026nbsp;\u0026nbsp;\u201cThe interdisciplinary research that he and his colleagues are\ndoing at Georgia Tech has the potential to dramatically change the electronics\nindustry by enabling the use of this promising material in future generations\nof high-performance electronic devices.\u201d\u003C\/p\u003E\n\n\n\n\u003Cp\u003EDe Heer\nearned a doctoral degree in physics from the University of California - Berkeley\nin 1986. He worked at the \u00c9cole Polytechnique F\u00e9d\u00e9rale de Lausanne in\nSwitzerland from 1987-1997.\u003C\/p\u003E\n\n\n\n\u003Cp\u003ECurrently a\nRegents\u0027 Professor of Physics at the Tech, de Heer directs the \u003Ca href=\u0022http:\/\/www.physics.gatech.edu\/npeg\/\u0022\u003EEpitaxial\nGraphene Laboratory\u003C\/a\u003E in the School of Physics and leads the Epitaxial Graphene\nInterdisciplinary Research Group at the Georgia Tech \u003Ca href=\u0022http:\/\/www.mrsec.gatech.edu\/\u0022\u003EMaterials Research Science\nand Engineering Center\u003C\/a\u003E.\u003C\/p\u003E\n\n\n\n\u003Cp\u003EDe Heer and\nhis research groups have made significant contributions to several areas in\nnanoscopic physics. In 1995, de Heer\u2019s research turned to carbon nanotubes,\nshowing that they are excellent field emitters with potential application to\nflat panel displays. In 1998, he discovered that carbon nanotubes are ballistic\nconductors, which is a key property for graphene-based electronics. \u003C\/p\u003E\n\n\n\n\u003Cp\u003EIn 2001, his\nwork on nanopatterned epi-graphene electronics led to the development of\ngraphene-based electronics. This project was funded by Intel Corporation in 2003\nand by the National Science Foundation (NSF) in 2004. His paper, \u003Cem\u003EUltrathin\nEpitaxial Graphite: Two-Dimensional Electron Gas Properties and a Route Towards\nGraphene-Based Electronics\u003C\/em\u003E, published in the Journal of Physical Chemistry,\nlaid the experimental and conceptual foundation for graphene-based electronics.\nDe Heer holds the first patent for graphene-based electronics that was\nprovisionally filed in June 2003.\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":[{"value":"De Heer cited for pioneering contributions to the science and technology of epitaxial graphene."}],"field_summary":[{"value":"\u003Cp\u003EWalt de Heer awarded Materials Research Society Medal for \u201cpioneering contributions to the science and technology of epitaxial graphene.\u201d\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"De Heer cited for pioneering contributions to the science and technology of epitaxial graphene."}],"uid":"27310","created_gmt":"2010-12-02 09:10:14","changed_gmt":"2016-10-08 03:07:50","author":"David Terraso","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2010-12-02T00:00:00-05:00","iso_date":"2010-12-02T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"hg_media":{"63023":{"id":"63023","type":"image","title":"Walt de Heer","body":null,"created":"1449176409","gmt_created":"2015-12-03 21:00:09","changed":"1475894549","gmt_changed":"2016-10-08 02:42:29","alt":"Walt de Heer","file":{"fid":"191703","name":"11C3031-P3-026.jpg","image_path":"\/sites\/default\/files\/images\/11C3031-P3-026.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/11C3031-P3-026.jpg","mime":"image\/jpeg","size":2600142,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/11C3031-P3-026.jpg?itok=6Lh_fwww"}}},"media_ids":["63023"],"related_links":[{"url":"http:\/\/www.physics.gatech.edu\/","title":"Georgia Tech School of Physics"},{"url":"http:\/\/www.physics.gatech.edu\/npeg\/","title":"Epitaxial Graphene Lab"},{"url":"http:\/\/www.mrsec.gatech.edu\/","title":"Materials Research Science and Engineering Center"}],"groups":[{"id":"1183","name":"Home"}],"categories":[{"id":"149","name":"Nanotechnology and Nanoscience"},{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"9826","name":"de Heer"},{"id":"10880","name":"epitaxial"},{"id":"429","name":"graphene"},{"id":"11375","name":"materials research society"},{"id":"1693","name":"MRS"},{"id":"11374","name":"walt"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EGeorgia Tech Media Relations\u003C\/strong\u003E\u003Cbr \/\u003ELaura Diamond\u003Cbr \/\u003E\u003Ca href=\u0022mailto:laura.diamond@comm.gatech.edu\u0022\u003Elaura.diamond@comm.gatech.edu\u003C\/a\u003E\u003Cbr \/\u003E404-894-6016\u003Cbr \/\u003EJason Maderer\u003Cbr \/\u003E\u003Ca href=\u0022mailto:maderer@gatech.edu\u0022\u003Emaderer@gatech.edu\u003C\/a\u003E\u003Cbr \/\u003E404-660-2926\u003C\/p\u003E","format":"limited_html"}],"email":["david.terraso@comm.gatech.edu"],"slides":[],"orientation":[],"userdata":""}},"61514":{"#nid":"61514","#data":{"type":"news","title":"Researchers Develop Techniques for Using Material Recognized in Nobel Prize","body":[{"value":"\u003Cp\u003EGeorgia Institute of Technology researchers have pioneered the fabrication techniques expected to be used for manufacturing high-performance electronic devices from the material that has been recognized in this year\u0027s Nobel Prize in physics. \u003C\/p\u003E\u003Cp\u003EThe 2010 physics prize was awarded for producing, isolating, identifying and characterizing graphene, a single atomic layer of carbon whose unique properties make the material attractive for electronic applications. Scientists at the University of Manchester were recognized for their work on graphene sheets peeled from blocks of graphite. \u003C\/p\u003E\u003Cp\u003EThe work of the Georgia Tech group, headed by Professor Walt de Heer in the Georgia Tech School of Physics, was recognized by the Royal Swedish Academy of Sciences in its scientific background document on the physics prize. De Heer\u0027s group pioneered epitaxial techniques for growing large-scale graphene sheets by heating wafers of silicon carbide to drive off the silicon, leaving a thin layer of graphene. \u003C\/p\u003E\u003Cp\u003EThe technique, which is now being used by research groups at companies such as IBM, has practical applications in large-scale production of electronic devices. On Oct. 3, the group published a paper in the journal \u003Cem\u003ENature Nanotechnology\u003C\/em\u003E describing a new technique used to produce an array of 10,000 graphene transistors. \u003C\/p\u003E\u003Cp\u003E\u0022We believe that our technique, or one very much like it, will ultimately be used to manufacture future generations of graphene-based electronic devices,\u0022 said de Heer. \u0022Using techniques that are suitable for scaling up for mass production, we can grow graphene in the patterns that we need for electronic devices.\u0022 \u003C\/p\u003E\u003Cp\u003EThe Georgia Tech group holds a patent, filed in 2003, on fabricating electronic devices from these graphene layers. \u003C\/p\u003E\u003Cp\u003EGeorgia Tech is home to a Materials Research Science and Engineering Center (MRSEC), funded by the National Science Foundation (NSF) and including collaborators from the University of California-Berkeley, University of California-Riverside and University of Michigan. The foundation focus of the center is research and development of epitaxial graphene. \u003C\/p\u003E\u003Cp\u003E\u0022The unique properties of graphene portend considerable promise for future electronic and optical devices,\u0022 said Dennis Hess, the center\u0027s director. \u0022If graphene is to serve as a viable successor to silicon-based microelectronic devices and circuits, large scale production on a suitable substrate is required. Proof of concept of this approach has already been demonstrated by the fabrication of a 10,000 epitaxial graphene transistor array by Walt de Heer and his collaborators. This achievement is a significant advance toward realizing carbon-based electronics for the 21st century.\u0022 \u003C\/p\u003E\u003Cp\u003EThe Georgia Tech team also collaborates with researchers at the National Institute of Standards and Technology (NIST) on characterizing the unique properties of graphene. That work has led to several recent important papers, in journals such as \u003Cem\u003EScience\u003C\/em\u003E and \u003Cem\u003ENature Physics\u003C\/em\u003E. The latter described for the first time how the orbits of electrons are distributed spatially by magnetic fields applied to layers of epitaxial graphene. \u003C\/p\u003E\u003Cp\u003EOn Oct. 3 in the advance online publication of the journal \u003Cem\u003ENature Nanotechnology\u003C\/em\u003E, de Heer and collaborators described the development of a new \u0022templated growth\u0022 technique for fabricating nanometer-scale graphene devices. The method addresses what had been a significant obstacle to the use of this promising material in future generations of high-performance electronic devices. \u003C\/p\u003E\u003Cp\u003EThe technique involves etching patterns into the silicon carbide surfaces on which epitaxial graphene is grown. The patterns serve as templates directing the growth of graphene structures, allowing the formation of nanoribbons of specific widths without the use of e-beams or other destructive cutting techniques. Templated nanoribbon growth addresses the edge roughness that causes electron scattering. \u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003EGeorgia Institute of Technology\u003Cbr \/\u003E75 Fifth Street, N.W., Suite 314\u003Cbr \/\u003EAtlanta, Georgia 30308 USA\u003C\/strong\u003E \u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts\u003C\/strong\u003E: John Toon (404-894-6986)(\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E) or Abby Vogel Robinson (404-385-3364)(\u003Ca href=\u0022mailto:abby@innovate.gatech.edu\u0022\u003Eabby@innovate.gatech.edu\u003C\/a\u003E). \u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: John Toon \u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EGeorgia Institute of Technology researchers have pioneered the fabrication techniques expected to be used for manufacturing high-performance electronic devices from the material that has been recognized in this year\u0027s Nobel Prize in physics.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Georgia Tech researchers were cited by Nobel Prize committee."}],"uid":"27303","created_gmt":"2010-10-07 00:00:00","changed_gmt":"2016-10-08 03:07:34","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2010-10-07T00:00:00-04:00","iso_date":"2010-10-07T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"61515":{"id":"61515","type":"image","title":"Walt de Heer in laboratory","body":null,"created":"1449176337","gmt_created":"2015-12-03 20:58:57","changed":"1475894536","gmt_changed":"2016-10-08 02:42:16","alt":"Walt de Heer in laboratory","file":{"fid":"191374","name":"tty62482.jpg","image_path":"\/sites\/default\/files\/images\/tty62482_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/tty62482_0.jpg","mime":"image\/jpeg","size":1471812,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/tty62482_0.jpg?itok=oZs1YRmK"}}},"media_ids":["61515"],"related_links":[{"url":"http:\/\/www.physics.gatech.edu\/","title":"Georgia Tech School of Physics"},{"url":"http:\/\/www.physics.gatech.edu\/people\/faculty\/wdeheer.html","title":"Walt de Heer"},{"url":"http:\/\/mrsec.gatech.edu\/","title":"Materials Research Science and Engineering Center (MRSEC)"}],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"141","name":"Chemistry and Chemical Engineering"},{"id":"145","name":"Engineering"},{"id":"149","name":"Nanotechnology and Nanoscience"},{"id":"135","name":"Research"},{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"1928","name":"devices"},{"id":"609","name":"electronics"},{"id":"10880","name":"epitaxial"},{"id":"429","name":"graphene"},{"id":"7435","name":"material"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EJohn Toon\u003C\/strong\u003E\u003Cbr \/\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=jt7\u0022\u003EContact John Toon\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-6986\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}},"61435":{"#nid":"61435","#data":{"type":"news","title":"New Graphene Fabrication Method Uses Silicon Carbide Template","body":[{"value":"\u003Cp\u003EResearchers at the Georgia Institute of Technology have developed a new \u201ctemplated growth\u201d technique for fabricating nanometer-scale graphene devices.  The method addresses what had been a significant obstacle to the use of this promising material in future generations of high-performance electronic devices.\u003C\/p\u003E\n\u003Cp\u003EThe technique involves etching patterns into the silicon carbide surfaces on which epitaxial graphene is grown.  The patterns serve as templates directing the growth of graphene structures, allowing the formation of nanoribbons of specific widths without the use of e-beams or other destructive cutting techniques.  Graphene nanoribbons produced with these templates have smooth edges that avoid electron-scattering problems.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022Using this approach, we can make very narrow ribbons of interconnected graphene without the rough edges,\u0022 said Walt de Heer, a professor in the Georgia Tech School of Physics.  \u0022Anything that can be done to make small structures without having to cut them is going to be useful to the development of graphene electronics because if the edges are too rough, electrons passing through the ribbons scatter against the edges and reduce the desirable properties of graphene.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EThe new technique has been used to fabricate an array of 10,000 top-gated graphene transistors on a 0.24 square centimeter chip \u2013 believed to be the largest density of graphene devices reported so far.\n\u003C\/p\u003E\n\u003Cp\u003EThe research was reported Oct. 3 in the advance online edition of the journal \u003Cem\u003ENature Nanotechnology\u003C\/em\u003E.  The work was supported by the National Science Foundation, the W.M. Keck Foundation and the Nanoelectronics Research Initiative Institute for Nanoelectronics Discovery and Exploration (INDEX).\n\u003C\/p\u003E\n\u003Cp\u003EIn creating their graphene nanostructures, De Heer and his research team first use conventional microelectronics techniques to etch tiny \u0022steps\u0022 \u2013 or contours \u2013 into a silicon carbide wafer.  They then heat the contoured wafer to approximately 1,500 degrees Celsius, which initiates melting that polishes any rough edges left by the etching process.\n\u003C\/p\u003E\n\u003Cp\u003EThey then use established techniques for growing graphene from silicon carbide by driving off the silicon atoms from the surface.  Instead of producing a consistent layer of graphene one atom thick across the surface of the wafer, however, the researchers limit the heating time so that graphene grows only on the edges of the contours.\n\u003C\/p\u003E\n\u003Cp\u003ETo do this, they take advantage of the fact that graphene grows more rapidly on certain facets of the silicon carbide crystal than on others.  The width of the resulting nanoribbons is proportional to the depth of the contour, providing a mechanism for precisely controlling the nanoribbons.  To form complex graphene structures, multiple etching steps can be carried out to create a complex template, de Heer explained.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022By using the silicon carbide to provide the template, we can grow graphene in exactly the sizes and shapes that we want,\u0022 he said. \u0022Cutting steps of various depths allows us to create graphene structures that are interconnected in the way we want them to be.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EIn nanometer-scale graphene ribbons, quantum confinement makes the material behave as a semiconductor suitable for creation of electronic devices.  But in ribbons a micron or more wide, the material acts as a conductor.  Controlling the depth of the silicon carbide template allows the researchers to create these different structures simultaneously, using the same growth process.  \n\u003C\/p\u003E\n\u003Cp\u003E\u0022The same material can be either a conductor or a semiconductor depending on its shape,\u0022 noted de Heer, who is also a faculty member in Georgia Tech\u2019s National Science Foundation-supported Materials Research Science and Engineering Center (MRSEC).  \u0022One of the major advantages of graphene electronics is to make the device leads and the semiconducting ribbons from the same material.  That\u0027s important to avoid electrical resistance that builds up at junctions between different materials.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EAfter formation of the nanoribbons \u2013 which can be as narrow as 40 nanometers \u2013 the researchers apply a dielectric material and metal gate to construct field-effect transistors.  While successful fabrication of high-quality transistors demonstrates graphene\u0027s viability as an electronic material, de Heer sees them as only the first step in what could be done with the material.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022When we manage to make devices well on the nanoscale, we can then move on to make much smaller and finer structures that will go beyond conventional transistors to open up the possibility for more sophisticated devices that use electrons more like light than particles,\u0022 he said.  \u0022If we can factor quantum mechanical features into electronics, that is going to open up a lot of new possibilities.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EDe Heer and his research team are now working to create smaller structures, and to integrate the graphene devices with silicon.  The researchers are also working to improve the field-effect transistors with thinner dielectric materials.\n\u003C\/p\u003E\n\u003Cp\u003EUltimately, graphene may be the basis for a generation of high-performance devices that will take advantage of the material\u0027s unique properties in applications where the higher cost can be justified.  Silicon will continue to be used in applications that don\u0027t require such high performance, de Heer said.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022This is another step showing that our method of working with epitaxial graphene on silicon carbide is the right approach and the one that will probably be used for making graphene electronics,\u0022 he added.  \u0022This is a significant new step toward electronics manufacturing with graphene.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EIn addition to those already mentioned, the research has involved M. Sprinkle, M. Ruan, Y Hu, J. Hankinson, M. Rubio-Roy, B. Zhang, X. Wu and C. Berger.\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\nGeorgia Institute of Technology\u003Cbr \/\u003E\n75 Fifth Street, N.W., Suite 314\u003Cbr \/\u003E\nAtlanta, Georgia  30308  USA\u003C\/strong\u003E\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts\u003C\/strong\u003E: John Toon (404-894-6986)(\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E) or Abby Vogel Robinson (404-385-3364)(\u003Ca href=\u0022mailto:abby@innovate.gatech.edu\u0022\u003Eabby@innovate.gatech.edu\u003C\/a\u003E).\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: John Toon\n\u003C\/p\u003E\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EGeorgia Tech researchers have developed a new \u0022templated growth\u0022 technique for fabricating nanometer-scale graphene devices.  The method addresses what had been a significant obstacle to the use of this promising material in future generations of high-performance electronic devices.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"A new template approach is being used to fabricate graphene devi"}],"uid":"27303","created_gmt":"2010-10-05 00:00:00","changed_gmt":"2016-10-08 03:07:34","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2010-10-05T00:00:00-04:00","iso_date":"2010-10-05T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"61436":{"id":"61436","type":"image","title":"Graphene transistors","body":null,"created":"1449176337","gmt_created":"2015-12-03 20:58:57","changed":"1475894536","gmt_changed":"2016-10-08 02:42:16","alt":"Graphene transistors","file":{"fid":"191358","name":"tcv90049.jpg","image_path":"\/sites\/default\/files\/images\/tcv90049_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/tcv90049_0.jpg","mime":"image\/jpeg","size":535060,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/tcv90049_0.jpg?itok=IZZUcHgA"}},"61437":{"id":"61437","type":"image","title":"Graphene nanoribbon","body":null,"created":"1449176337","gmt_created":"2015-12-03 20:58:57","changed":"1475894536","gmt_changed":"2016-10-08 02:42:16","alt":"Graphene nanoribbon","file":{"fid":"191359","name":"trf90049.jpg","image_path":"\/sites\/default\/files\/images\/trf90049_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/trf90049_0.jpg","mime":"image\/jpeg","size":609209,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/trf90049_0.jpg?itok=I30e2Uoy"}}},"media_ids":["61436","61437"],"related_links":[{"url":"http:\/\/www.physics.gatech.edu\/","title":"Georgia Tech School of Physics"},{"url":"http:\/\/www.physics.gatech.edu\/people\/faculty\/wdeheer.html","title":"Walt de Heer"},{"url":"http:\/\/mrsec.gatech.edu\/","title":"Materials Research Science and Engineering Center (MRSEC)"}],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"141","name":"Chemistry and Chemical Engineering"},{"id":"145","name":"Engineering"},{"id":"149","name":"Nanotechnology and Nanoscience"},{"id":"135","name":"Research"},{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"1928","name":"devices"},{"id":"4264","name":"fabrication"},{"id":"429","name":"graphene"},{"id":"10851","name":"template"},{"id":"7528","name":"transistors"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EJohn Toon\u003C\/strong\u003E\u003Cbr \/\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=jt7\u0022\u003EContact John Toon\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-6986\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}},"60861":{"#nid":"60861","#data":{"type":"news","title":"Instrument Reveals Quartet of Graphene Electron States","body":[{"value":"\u003Cp\u003EUsing a one-of-a-kind instrument designed and built at the National Institute of Standards and Technology (NIST), researchers have \u0022unveiled\u0022 a quartet of graphene\u0027s electron states and discovered that electrons in graphene can split up into an unexpected and tantalizing set of energy levels when exposed to extremely low temperatures and extremely high magnetic fields. \u003C\/p\u003E\u003Cp\u003EReported Sept. 9 in the journal \u003Cem\u003ENature\u003C\/em\u003E, the new research raises several intriguing questions about the fundamental physics of this exciting material and reveals new effects that may make graphene even more powerful than previously expected for practical applications. \u003C\/p\u003E\u003Cp\u003ELed by NIST Fellow Joseph Stroscio, the research team included scientists from the Georgia Institute of Technology, the University of Maryland, Seoul National University, and the University of Texas at Austin. \u003C\/p\u003E\u003Cp\u003EGraphene is one of the simplest materials -- a single-atom-thick sheet of carbon atoms arranged in a honeycomb-like lattice -- yet it has many remarkable and surprisingly complex properties. Measuring and understanding how electrons carry current through the sheet is a key to achieving its technological promise in wide-ranging applications, including high speed electronics and sensors. \u003C\/p\u003E\u003Cp\u003EFor example, the electrons in graphene act as if they have no mass and are almost 100 times more mobile than in silicon. Moreover, the speed with which electrons move through graphene is not related to their energy, unlike materials such as silicon where more voltage must be applied to increase their speed, which creates heat that is detrimental to most applications. \u003C\/p\u003E\u003Cp\u003ETo fully understand the behavior of graphene\u0027s electrons, scientists must study the material under an extreme environment of ultra-high vacuum, ultra-low temperatures, and large magnetic fields. Under these conditions, the graphene sheet remains pristine for weeks. \u003C\/p\u003E\u003Cp\u003ENIST has recently constructed the world\u2019s most powerful and stable scanning-probe microscope, with an unprecedented combination of low temperature (as low as 10 millikelvin, or 10 thousandths of a degree above absolute zero), ultra-high vacuum, and high magnetic field. In the first measurements made with this instrument, the international team has used its power to resolve the finest differences in the electron energies in graphene, atom-by-atom. \u003C\/p\u003E\u003Cp\u003E\u0022Going to this resolution allows you to see new physics,\u0022 said Young Jae Song, a postdoctoral researcher who helped develop the instrument at NIST and make these first measurements. \u003C\/p\u003E\u003Cp\u003EAnd the new physics the team saw raises a few more questions about how the electrons behave in graphene than it answers. \u003C\/p\u003E\u003Cp\u003EBecause of the geometry and electromagnetic properties of graphene\u0027s structure, an electron in any given energy level populates four possible sublevels, called a \u0022quartet.\u0022 Theorists have predicted that this quartet of levels would split into different energies when immersed in a magnetic field, but until recently there had not been an instrument sensitive enough to resolve these differences. \u003C\/p\u003E\u003Cp\u003E\u0022When we increased the magnetic field at extreme low temperatures, we observed unexpectedly complex quantum behavior of the electrons,\u0022 said NIST Fellow Joseph Stroscio. \u003C\/p\u003E\u003Cp\u003EWhat is happening, according to Stroscio, appears to be a \u0022many-body effect\u0022 in which electrons interact strongly with one another in ways that affect their energy levels. \u003C\/p\u003E\u003Cp\u003EOne possible explanation for this behavior is that the electrons have formed a \u0022condensate\u0022 in which they cease moving independently of one another and act as a single coordinated unit. \u003C\/p\u003E\u003Cp\u003EThe new experiments also showed surprising stability in the quartet states, an issue that warrants further study, said Phillip First, a professor in Georgia Tech\u0027s School of Physics and one of the study\u0027s co-authors. \u003C\/p\u003E\u003Cp\u003E\u0022The experiment shows that these magnetic configurations become especially stable when any one of the quartet states is completely filled with electrons, which indicates the importance of many-body correlations,\u0022 he said. \u0022However, the most surprising thing is the observation of new stable states that occur when a quartet state is exactly half filled. That\u0027s pretty remarkable, and we still need an explanation.\u0022 \u003C\/p\u003E\u003Cp\u003EGraphene has attracted strong interest as a potential material for future electronic devices, and this new work reinforces that expectation. \u003C\/p\u003E\u003Cp\u003E\u0022If our hypothesis proves to be correct, it could point the way to the creation of smaller, very-low-heat producing, highly energy efficient electronic devices based upon graphene,\u0022 said Shaffique Adam, a postdoctoral researcher who assisted with theoretical analysis of the measurements. \u003C\/p\u003E\u003Cp\u003EIn addition to First, Georgia Tech researchers contributing to the paper included Walt de Heer, Yike Hu and David Torrance. The research was supported in part by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD)(KRF-2006-214-C00022), the National Science Foundation (DMR-0820382 [MRSEC], DMR-0804908, DMR-0606489), the Welch Foundation and the Semiconductor Research Corporation (NRI-INDEX program). \u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003EGeorgia Institute of Technology\u003Cbr \/\u003E75 Fifth Street, N.W., Suite 314\u003Cbr \/\u003EAtlanta, Georgia 30308 USA\u003C\/strong\u003E \u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts\u003C\/strong\u003E: Mark Esser, NIST, (301-975-8735)(\u003Ca href=\u0022mailto:mark.esser@nist.gov\u0022\u003Emark.esser@nist.gov\u003C\/a\u003E) or John Toon, Georgia Tech, (404-894-6986)(\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E). \u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: Mark Esser \u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EUsing a one-of-a-kind instrument designed and built at the National Institute of Standards and Technology (NIST), researchers have \u0022unveiled\u0022 a quartet of graphene\u0027s electron states and discovered that electrons in graphene can split up into an unexpected and tantalizing set of energy levels when exposed to extremely low temperatures and extremely high magnetic fields.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Research yields new information on graphene\u0027s electron states."}],"uid":"27303","created_gmt":"2010-09-07 00:00:00","changed_gmt":"2016-10-08 03:07:23","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2010-09-07T00:00:00-04:00","iso_date":"2010-09-07T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"60862":{"id":"60862","type":"image","title":"NIST scanning probe microscope","body":null,"created":"1449176296","gmt_created":"2015-12-03 20:58:16","changed":"1475894528","gmt_changed":"2016-10-08 02:42:08","alt":"NIST scanning probe microscope","file":{"fid":"191227","name":"trm09953.jpg","image_path":"\/sites\/default\/files\/images\/trm09953_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/trm09953_0.jpg","mime":"image\/jpeg","size":1261222,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/trm09953_0.jpg?itok=0h08uyMH"}}},"media_ids":["60862"],"related_links":[{"url":"http:\/\/www.mrsec.gatech.edu\/","title":"Materials Research Science and Engineering Center"},{"url":"http:\/\/www.physics.gatech.edu\/","title":"Georgia Tech School of Physics"}],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"145","name":"Engineering"},{"id":"149","name":"Nanotechnology and Nanoscience"},{"id":"135","name":"Research"},{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"10597","name":"electron state"},{"id":"10599","name":"energy level"},{"id":"429","name":"graphene"},{"id":"10598","name":"NIST"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EJohn Toon\u003C\/strong\u003E\u003Cbr \/\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=jt7\u0022\u003EContact John Toon\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-6986\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}},"60372":{"#nid":"60372","#data":{"type":"news","title":"Study of Electron Orbits in Multilayer Graphene Finds Energy Gaps","body":[{"value":"\u003Cp\u003EResearchers have taken one more step toward understanding the unique and often unexpected properties of graphene, a two-dimensional carbon material that has attracted interest because of its potential applications in future generations of electronic devices.\u003C\/p\u003E\u003Cp\u003EIn the Aug. 8 advance online edition of the journal \u003Cem\u003ENature Physics\u003C\/em\u003E, researchers from the Georgia Institute of Technology and the National Institute of Standards and Technology (NIST) describe for the first time how the orbits of electrons are distributed spatially by magnetic fields applied to layers of epitaxial graphene. \u003C\/p\u003E\u003Cp\u003EThe research team also found that these electron orbits can interact with the substrate on which the graphene is grown, creating energy gaps that affect how electron waves move through the multilayer material. These energy gaps could have implications for the designers of certain graphene-based electronic devices. \u003C\/p\u003E\u003Cp\u003E\u0022The regular pattern of energy gaps in the graphene surface creates regions where electron transport is not allowed,\u0022 said Phillip N. First, a professor in the Georgia Tech School of Physics and one of the paper\u2019s co-authors. \u0022Electron waves would have to go around these regions, requiring new patterns of electron wave interference. Understanding such interference will be important for bi-layer graphene devices that have been proposed, and may be important for other lattice-matched substrates used to support graphene and graphene devices.\u0022 \u003C\/p\u003E\u003Cp\u003EIn a magnetic field, an electron moves in a circular trajectory -- known as a cyclotron orbit -- whose radius depends on the size of the magnetic field and the energy of electron. For a constant magnetic field, that\u0027s a little like rolling a marble around in a large bowl, First said. \u003C\/p\u003E\u003Cp\u003E\u0022At high energy, the marble orbits high in the bowl, while for lower energies, the orbit size is smaller and lower in the bowl,\u0022 he explained. \u0022The cyclotron orbits in graphene also depend on the electron energy and the local electron potential -- corresponding to the bowl -- but until now, the orbits hadn\u2019t been imaged directly.\u0022 \u003C\/p\u003E\u003Cp\u003EPlaced in a magnetic field, these orbits normally drift along lines of nearly constant electric potential. But when a graphene sample has small fluctuations in the potential, these \u0022drift states\u0022 can become trapped at a hill or valley in the material that has closed constant potential contours. Such trapping of charge carriers is important for the quantum Hall effect, in which precisely quantized resistance results from charge conduction solely through the orbits that skip along the edges of the material. \u003C\/p\u003E\u003Cp\u003EThe study focused on one particular electron orbit: a zero-energy orbit that is unique to graphene. Because electrons are matter waves, interference within a material affects how their energy relates to the velocity of the wave -- and reflected waves added to an incoming wave can combine to produce a slower composite wave. Electrons moving through the unique \u0022chicken-wire\u0022 arrangement of carbon-carbon bonds in the graphene interfere in a way that leaves the wave velocity the same for all energy levels. \u003C\/p\u003E\u003Cp\u003EIn addition to finding that energy states follow contours of constant electric potential, the researchers discovered specific areas on the graphene surface where the orbital energy of the electrons changes from one atom to the next. That creates an energy gap within isolated patches on the surface. \u003C\/p\u003E\u003Cp\u003E\u0022By examining their distribution over the surface for different magnetic fields, we determined that the energy gap is due to a subtle interaction with the substrate, which consists of multilayer graphene grown on a silicon carbide wafer,\u0022 First explained. \u003C\/p\u003E\u003Cp\u003EIn multilayer epitaxial graphene, each layer\u0027s symmetrical sublattice is rotated slightly with respect to the next. In prior studies, researchers found that the rotations served to decouple the electronic properties of each graphene layer. \u003C\/p\u003E\u003Cp\u003E\u0022Our findings hold the first indications of a small position-dependent interaction between the layers,\u0022 said David L. Miller, the paper\u0027s first author and a graduate student in First\u0027s laboratory. \u0022This interaction occurs only when the size of a cyclotron orbit -- which shrinks as the magnetic field is increased -- becomes smaller than the size of the observed patches.\u0022 \u003C\/p\u003E\u003Cp\u003EThe origin of the position dependent interaction is believed to be the \u0022moir\u00e9 pattern\u0022 of atomic alignments between two adjacent layers of graphene. In some regions, atoms of one layer lie atop atoms of the layer below, while in other regions, none of the atoms align with the atoms in the layer below. In still other regions, half of the atoms have neighbors in the underlayer, an instance in which the symmetry of the carbon atoms is broken and the Landau level -- discrete energy level of the electrons -- splits into two different energies. \u003C\/p\u003E\u003Cp\u003EExperimentally, the researchers examined a sample of epitaxial graphene grown at Georgia Tech in the laboratory of Professor Walt de Heer, using techniques developed by his research team over the past several years. \u003C\/p\u003E\u003Cp\u003EThey used the tip of a custom-built scanning-tunneling microscope (STM) to probe the atomic-scale electronic structure of the graphene in a technique known as scanning tunneling spectroscopy. The tip was moved across the surface of a 100-square nanometer section of graphene, and spectroscopic data was acquired every 0.4 nanometers. \u003C\/p\u003E\u003Cp\u003EThe measurements were done at 4.3 degrees Kelvin to take advantage of the fact that energy resolution is proportional to the temperature. The scanning-tunneling microscope, designed and built by Joseph Stroscio at NIST\u0027s Center for Nanoscale Science and Technology, used a superconducting magnet to provide the magnetic fields needed to study the orbits. \u003C\/p\u003E\u003Cp\u003EAccording to First, the study raises a number of questions for future research, including how the energy gaps will affect electron transport properties, how the observed effects may impact proposed bi-layer graphene coherent devices -- and whether the new phenomenon can be controlled. \u003C\/p\u003E\u003Cp\u003E\u0022This study is really a stepping stone in long path to understanding the subtleties of graphene\u0027s interesting properties,\u0022 he said. \u0022This material is different from anything we have worked with before in electronics.\u0022 \u003C\/p\u003E\u003Cp\u003EIn addition to those already mentioned, the study also included Walt de Heer, Kevin D. Kubista, Ming Ruan, and Markus Kinderman from Georgia Tech and Gregory M. Rutter from NIST. The research was supported by the National Science Foundation, the Semiconductor Research Corporation and the W.M. Keck Foundation. Additional assistance was provided by Georgia Tech\u0027s Materials Research Science and Engineering Center (MRSEC). \u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003EGeorgia Institute of Technology\u003Cbr \/\u003E75 Fifth Street, N.W., Suite 314\u003Cbr \/\u003EAtlanta, Georgia 30308 USA\u003C\/strong\u003E \u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts\u003C\/strong\u003E: John Toon (404-894-6986)(\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E) or Abby Vogel Robinson (404-385-3364)(\u003Ca href=\u0022mailto:abby@innovate.gatech.edu\u0022\u003Eabby@innovate.gatech.edu\u003C\/a\u003E). \u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: John Toon \u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":[{"value":"Findings May Have Implications for Device Designers"}],"field_summary":[{"value":"\u003Cp\u003EResearchers have taken one more step toward understanding the unique and often unexpected properties of graphene, a two-dimensional carbon material that has attracted interest because of its potential applications in future generations of electronic devices.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Researchers take a new step to understanding graphene properties."}],"uid":"27303","created_gmt":"2010-08-09 00:00:00","changed_gmt":"2016-10-08 03:07:15","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2010-08-09T00:00:00-04:00","iso_date":"2010-08-09T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"60373":{"id":"60373","type":"image","title":"Moire alignment of graphene","body":null,"created":"1449176267","gmt_created":"2015-12-03 20:57:47","changed":"1475894523","gmt_changed":"2016-10-08 02:42:03","alt":"Moire alignment of graphene","file":{"fid":"191110","name":"tpx85581.jpg","image_path":"\/sites\/default\/files\/images\/tpx85581_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/tpx85581_0.jpg","mime":"image\/jpeg","size":953599,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/tpx85581_0.jpg?itok=4b2fa4es"}},"60374":{"id":"60374","type":"image","title":"Graphene Electron Motion","body":null,"created":"1449176267","gmt_created":"2015-12-03 20:57:47","changed":"1475894523","gmt_changed":"2016-10-08 02:42:03","alt":"Graphene Electron Motion","file":{"fid":"191111","name":"tdc85581.jpg","image_path":"\/sites\/default\/files\/images\/tdc85581_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/tdc85581_0.jpg","mime":"image\/jpeg","size":192342,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/tdc85581_0.jpg?itok=TH4hzXiY"}}},"media_ids":["60373","60374"],"related_links":[{"url":"http:\/\/www.physics.gatech.edu\/","title":"Georgia Tech School of Physics"},{"url":"http:\/\/www.mrsec.gatech.edu\/","title":"Materials Research Science and Engineering Center"},{"url":"http:\/\/www.physics.gatech.edu\/people\/faculty\/pfirst.html","title":"Phillip First"}],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"149","name":"Nanotechnology and Nanoscience"},{"id":"135","name":"Research"},{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"6884","name":"electron"},{"id":"609","name":"electronics"},{"id":"429","name":"graphene"},{"id":"10361","name":"orbits"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EJohn Toon\u003C\/strong\u003E\u003Cbr \/\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=jt7\u0022\u003EContact John Toon\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-6986\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}},"55557":{"#nid":"55557","#data":{"type":"news","title":"Seeing Moire in Graphene","body":[{"value":"\u003Cp\u003EResearchers at the Georgia Institute of Technology and the National Institute of Standards and Technology (NIST) have demonstrated that atomic scale moir\u00e9 patterns, an interference pattern that appears when two or more grids are overlaid slightly askew, can be used to measure how sheets of graphene are stacked and reveal areas of strain. The ability to determine the rotational orientation of graphene sheets and map strain is useful for understanding the electronic and transport properties of multiple layers of graphene, a one-atom thick form of carbon with potentially revolutionary semiconducting properties. The research appears in the journal, Physical Review B, in volume 81, issue 12.\u003Cbr \/\u003E\u003Cbr \/\u003EIn digital photography, moir\u00e9 (pronounced mwar-ray) patterns occur because of errors in the rendering process, which causes grid patterns to look wavy or distorted. Materials scientists have been using microscopic moir\u00e9 patterns to detect stresses such as wrinkles or bulges in a variety of materials.\u003Cbr \/\u003E\u003Cbr \/\u003EResearchers created graphene on the surface of a silicon carbide substrate at the Georgia Institute of Technology by heating one side so that only carbon, in the form of multilayer sheets of graphene, was left. Using a custom-built scanning tunneling microscope at NIST, the researchers were able to peer through the topmost layers of graphene to the layers beneath. This process, which the group dubbed \u0022atomic moir\u00e9 interferometry,\u0022 enabled them to image the patterns created by the stacked graphene layers, which in turn allowed the group to model how the hexagonal lattices of the individual graphene layers were stacked in relation to one another.\u003Cbr \/\u003E\u003Cbr \/\u003EUnlike other materials that tend to stretch out when they cool, graphene bunches up like a wrinkled bed sheet. The researchers were able to map these stress fields by comparing the relative distortion of the hexagons of carbon atoms that comprise the individual graphene layers. Their technique is so sensitive that it is able to detect strains in the graphene layers causing as little as a 0.1 percent change in atom spacing.\u003Cbr \/\u003E\u003Cbr \/\u003E\u201cThere\u2019s an ideal atomic lattice spacing in graphene. Knowing the strain distribution can help us in our efforts to create graphene with good electronic properties,\u201d said Phillip N. First, professor in the School of Physics at Georgia Tech. \u201cSo far, it looks as if multi-layered graphene has excellent conduction properties and may be useful for electronic applications.\u201d\u003Cbr \/\u003E\u003Cbr \/\u003EThis collaboration between Georgia Tech and NIST is part of a series of experiments aimed at gaining a fundamental understanding of the properties of graphene. Other examples of the group\u0027s work can been seen at \u003Ca href=\u0022http:\/\/www.mrs.org\/s_mrs\/bin.asp?CID=8684\u0026amp;DID=320520\u0026amp;DOC=FILE.PDF\u0022 title=\u0022www.mrs.org\/s_mrs\/bin.asp?CID=8684\u0026amp;DID=320520\u0026amp;DOC=FILE.PDF\u0022\u003Ewww.mrs.org\/s_mrs\/bin.asp?CID=8684\u0026amp;DID=320520\u0026amp;DOC=FILE.PDF\u003C\/a\u003E and \u003Ca href=\u0022http:\/\/www.mrs.org\/s_mrs\/bin.asp?CID=26616\u0026amp;DID=320529\u0026amp;DOC=FILE.PDF\u0022 title=\u0022www.mrs.org\/s_mrs\/bin.asp?CID=26616\u0026amp;DID=320529\u0026amp;DOC=FILE.PDF\u0022\u003Ewww.mrs.org\/s_mrs\/bin.asp?CID=26616\u0026amp;DID=320529\u0026amp;DOC=FILE.PDF\u003C\/a\u003E.\u003Cbr \/\u003E\u003Cbr \/\u003ETheir article, \u0022Structural analysis of multilayer graphene via atomic moir\u00e9 interferometry\u0022 was selected as an Editor\u0027s Highlight in Physical Review B for the month of March, 2010.\u003Cbr \/\u003E\u003Cbr \/\u003EWriters: Mark Esser and David Terraso\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EResearchers at the Georgia Institute of Technology and the National Institute of Standards and Technology have demonstrated that atomic scale moir\u00e9 patterns, an interference pattern that appears when two or more grids are overlaid slightly askew, can be used to measure how sheets of graphene are stacked and reveal areas of strain. \u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Researchers show how moire patterns can be used to meausure the strain of graphene sheets."}],"uid":"27310","created_gmt":"2010-05-05 08:55:51","changed_gmt":"2016-10-08 03:05:53","author":"David Terraso","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2010-05-05T00:00:00-04:00","iso_date":"2010-05-05T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"55558":{"id":"55558","type":"image","title":"Atomic Moire Pattern of Graphene","body":null,"created":"1449175533","gmt_created":"2015-12-03 20:45:33","changed":"1475894491","gmt_changed":"2016-10-08 02:41:31","alt":"Atomic Moire Pattern of Graphene","file":{"fid":"190314","name":"21977_web.jpg","image_path":"\/sites\/default\/files\/images\/21977_web_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/21977_web_0.jpg","mime":"image\/jpeg","size":73860,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/21977_web_0.jpg?itok=Vc-GC1Je"}}},"media_ids":["55558"],"groups":[{"id":"1183","name":"Home"}],"categories":[{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"429","name":"graphene"},{"id":"9244","name":"moire"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EGeorgia Tech Media Relations\u003C\/strong\u003E\u003Cbr \/\u003ELaura Diamond\u003Cbr \/\u003E\u003Ca href=\u0022mailto:laura.diamond@comm.gatech.edu\u0022\u003Elaura.diamond@comm.gatech.edu\u003C\/a\u003E\u003Cbr \/\u003E404-894-6016\u003Cbr \/\u003EJason Maderer\u003Cbr \/\u003E\u003Ca href=\u0022mailto:maderer@gatech.edu\u0022\u003Emaderer@gatech.edu\u003C\/a\u003E\u003Cbr \/\u003E404-660-2926\u003C\/p\u003E","format":"limited_html"}],"email":["david.terraso@comm.gatech.edu"],"slides":[],"orientation":[],"userdata":""}},"62422":{"#nid":"62422","#data":{"type":"news","title":"Templates let graphene grow","body":[{"value":"\u003Cp\u003E\u003Ca title=\u0022Templates let graphene grow\u0022 href=\u0022http:\/\/www.futurity.org\/science-technology\/templates-let-graphene-grow\/\u0022\u003EWhile successful fabrication of high-quality transistors demonstrates graphene\u0027s viability as an electronic material, Walt de Heer sees them as only the first step in what could be done with the material. Pictured above is a graphene transistor.\u003C\/a\u003E\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":[{"value":"Templates let graphene grow"}],"field_summary":[{"value":"\u003Cp\u003E\u003Ca title=\u0022Templates let graphene grow\u0022 href=\u0022http:\/\/www.futurity.org\/science-technology\/templates-let-graphene-grow\/\u0022\u003EWhile successful fabrication of high-quality transistors demonstrates graphene\u0027s viability as an electronic material, Walt de Heer sees them as only the first step in what could be done with the material. Pictured above is a graphene transistor.\u003C\/a\u003E\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"While successful fabrication of high-quality transistors demonstrates graphene\u0027s viability as an electronic material, Walt de Heer sees them as only the first step in what could be done with the material. Pictured above is a graphene transistor."}],"uid":"27428","created_gmt":"2010-10-29 16:27:56","changed_gmt":"2016-10-08 03:07:42","author":"Gina Adams","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2010-10-29T00:00:00-04:00","iso_date":"2010-10-29T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"63027":{"id":"63027","type":"image","title":"Templates let graphene grow","body":null,"created":"1449176409","gmt_created":"2015-12-03 21:00:09","changed":"1475894549","gmt_changed":"2016-10-08 02:42:29","alt":"Templates let graphene grow","file":{"fid":"191705","name":"nnano_2010_192-f8.jpg","image_path":"\/sites\/default\/files\/images\/nnano_2010_192-f8_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/nnano_2010_192-f8_0.jpg","mime":"image\/jpeg","size":86735,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/nnano_2010_192-f8_0.jpg?itok=mB7c5mlX"}}},"media_ids":["63027"],"groups":[{"id":"60783","name":"MRSEC"}],"categories":[{"id":"149","name":"Nanotechnology and Nanoscience"}],"keywords":[{"id":"429","name":"graphene"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}},"60893":{"#nid":"60893","#data":{"type":"news","title":"Scientists Gather for Symposium on Epitaxial Graphene","body":[{"value":"\u003Cp\u003EScientists from around the world will gather next week to\ndiscuss the latest research findings at the second International\nSymposium on the Science and Technology of Epitaxial Graphene. The conference\nis sponsored by the Materials Research Science and Engineering Center at the\nGeorgia Institute of Technology. It will take place September 14-17, 2010, at\nthe Hampton Inn \u0026amp; Suites Amelia Island Historic Harbor Front Hotel in\nAmelia Island, Florida. \u003C\/p\u003E\n\n\n\n\u003Cp\u003E\u201cThe symposium brings together engineers and scientists from\naround the world to discuss recent progress and future trends in the rapidly\ndeveloping science and technology of epitaxial graphene,\u201d said Walt de Heer,\nRegents\u2019 Professor in Georgia Tech\u2019s School\nof Physics and a pioneer in graphene-based electronics. \u201cThe symposium will\ncover a broad range of epitaxial graphene on silicon carbide\ntopics,\u0026nbsp;including surface science and growth, transport, optical\nproperties, chemistry, devices and\ntheory.\u0026nbsp; The discussions during this symposium will help to establish the\nfuture directions of epitaxial graphene science and technology.\u201d\u003C\/p\u003E\n\n\n\n\u003Cp\u003EThe symposium was first held in 2009 and is expected to be a\nyearly gathering. This year 130 attendees are expected. In addition to scientists\nfrom Georgia Tech, researchers from institutions such as the University of\nCalifornia, the National Institute of Standards and Technology, \u0026nbsp;the French National Center for\nScientific Research (CNRS), the German Max Planck Institute, the Japanese NTT\nlabs\u0026nbsp; and\u0026nbsp; several representatives from industry will be in attendance.\n\u003C\/p\u003E\n\n\n\n\u003Cp\u003ESo far, the substance has shown great promise in being a\nmaterial that can conduct electricity with little resistance without many of\nthe problems that carbon nanotubes have exhibited, such as difficulties with\nplacing them and building them into wires. In addition, research suggests that\nepitaxial graphene may offer much greater speed and performance over silicon.\u003C\/p\u003E\n\n\u003Cp\u003EScientists at the symposium will discuss the recent results\nof their research and will likely plan future scientific endeavors in this\nfield. \u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EScientists from around the world will gather next week to\ndiscuss the latest research findings at the second International Symposium on\nthe Science and Technology of Epitaxial Graphene. The conference is sponsored by\nthe Materials Research Science and Engineering Center at the Georgia Institute\nof Technology. It will take place September 14-17, 2010, at the Hampton Inn\n\u0026amp; Suites Amelia Island Historic Harbor Front Hotel in Amelia Island,\nFlorida. \u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Symposium takes place at Amelia Island September 14-17."}],"uid":"27310","created_gmt":"2010-09-10 08:21:29","changed_gmt":"2016-10-08 03:07:23","author":"David Terraso","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2010-09-10T00:00:00-04:00","iso_date":"2010-09-10T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"61437":{"id":"61437","type":"image","title":"Graphene nanoribbon","body":null,"created":"1449176337","gmt_created":"2015-12-03 20:58:57","changed":"1475894536","gmt_changed":"2016-10-08 02:42:16","alt":"Graphene nanoribbon","file":{"fid":"191359","name":"trf90049.jpg","image_path":"\/sites\/default\/files\/images\/trf90049_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/trf90049_0.jpg","mime":"image\/jpeg","size":609209,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/trf90049_0.jpg?itok=I30e2Uoy"}}},"media_ids":["61437"],"groups":[{"id":"1183","name":"Home"}],"categories":[{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"10615","name":"deHeer"},{"id":"429","name":"graphene"},{"id":"960","name":"physics"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EGeorgia Tech Media Relations\u003C\/strong\u003E\u003Cbr \/\u003ELaura Diamond\u003Cbr \/\u003E\u003Ca href=\u0022mailto:laura.diamond@comm.gatech.edu\u0022\u003Elaura.diamond@comm.gatech.edu\u003C\/a\u003E\u003Cbr \/\u003E404-894-6016\u003Cbr \/\u003EJason Maderer\u003Cbr \/\u003E\u003Ca href=\u0022mailto:maderer@gatech.edu\u0022\u003Emaderer@gatech.edu\u003C\/a\u003E\u003Cbr \/\u003E404-660-2926\u003C\/p\u003E","format":"limited_html"}],"email":["david.terraso@comm.gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}