Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > UT Austin researchers grow large graphene crystals that have exceptional electrical properties

Yufeng Hao, postdoctoral fellow at The University of Texas at Austin, demonstrates large, single graphene crystals grown on copper.

Credit: The Cockrell School of Engineering at The University of Texas at Austin
Yufeng Hao, postdoctoral fellow at The University of Texas at Austin, demonstrates large, single graphene crystals grown on copper.

Credit: The Cockrell School of Engineering at The University of Texas at Austin

Abstract:
When it comes to the growth of graphene an ultrathin, ultrastrong, all-carbon material it is survival of the fittest, according to researchers at The University of Texas at Austin.

UT Austin researchers grow large graphene crystals that have exceptional electrical properties

Austin, TX | Posted on November 14th, 2013

The team used surface oxygen to grow centimeter-size single graphene crystals on copper. The crystals were about 10,000 times as large as the largest crystals from only four years ago. Very large single crystals have exceptional electrical properties.

"The game we play is that we want nucleation (the growth of tiny 'crystal seeds') to occur, but we also want to harness and control how many of these tiny nuclei there are, and which will grow larger," said Rodney S. Ruoff, professor in the Cockrell School of Engineering. "Oxygen at the right surface concentration means only a few nuclei grow, and winners can grow into very large crystals."

The team led by postdoctoral fellow Yufeng Hao and Ruoff of the Department of Mechanical Engineering and the Materials Science and Engineering Program, along with Luigi Colombo, a material scientist with Texas Instruments worked for three years on the graphene growth method. The team's paper, "The Role of Surface Oxygen in the Growth of Large Single-Crystal Graphene on Copper," is featured on the cover of the Nov. 8, 2013, issue of Science.

One of the world's strongest materials, graphene is flexible and has high electrical and thermal conductivity that makes it a promising material for flexible electronics, solar cells, batteries and high-speed transistors. The team's understanding of how graphene growth is influenced by differing amounts of surface oxygen is a major step toward improved high-quality graphene films at industrial scale.

The team's method "is a fundamental breakthrough, which will lead to growth of high-quality and large area graphene film," said Sanjay Banerjee, who heads the Cockrell School's South West Academy of Nanoelectronics (SWAN). "By increasing the single-crystal domain sizes, the electronic transport properties will be dramatically improved and lead to new applications in flexible electronics."

Graphene has always been grown in a polycrystalline form, that is, it is composed of many crystals that are joined together with irregular chemical bonding at the boundaries between crystals ("grain boundaries"), something like a patch-work quilt. Large single-crystal graphene is of great interest because the grain boundaries in polycrystalline material have defects, and eliminating such defects makes for a better material.

By controlling the concentration of surface oxygen, the researchers could increase the crystal size from a millimeter to a centimeter. Rather than hexagon-shaped and smaller crystals, the addition of the right amount of surface oxygen produced much larger single crystals with multibranched edges, similar to a snowflake.

"In the long run it might be possible to achieve meter-length single crystals," Ruoff said. "This has been possible with other materials, such as silicon and quartz. Even a centimeter crystal size if the grain boundaries are not too defective is extremely significant."

"We can start to think of this material's potential use in airplanes and in other structural applications if it proves to be exceptionally strong at length scales like parts of an airplane wing, and so on," he said.

Another major finding by the team was that the "carrier mobility" of electrons (how fast the electrons move) in graphene films grown in the presence of surface oxygen is exceptionally high. This is important because the speed at which the charge carriers move is important for many electronic devices the higher the speed, the faster the device can perform.

Yufeng Hao says he thinks the knowledge gained in this study could prove useful to industry.

"The high quality of the graphene grown by our method will likely be developed further by industry, and that will eventually allow devices to be faster and more efficient," Hao said.

Single-crystal films can also be used for the evaluation and development of new types of devices that call for a larger scale than could be achieved before, added Colombo.

"At this time, there are no other reported techniques that can provide high quality transferrable films," Colombo said. "The material we were able to grow will be much more uniform in its properties than a polycrystalline film."

###

This study was funded at UT Austin by the W.M. Keck Foundation, the Office of Naval Research and the Southwest Area Nanotechnology Center (SWAN), which is supported by the Nanoelectronics Research Initiative (NRI). The paper's co-authors are from the Cockrell School of Engineering and the Department of Physics. Other co-authors are from Columbia University, A*STAR (in Singapore), Sandia National Laboratories-Livermore, Rice University and Texas Instruments.

Disclosure:

The University of Texas at Austin is committed to transparency and disclosure of all potential conflicts of interest of its researchers. Ruoff has received funding for graphene research from various public and private entities, including the Office of Naval Research and the W.M. Keck Foundation. He is a member of the American Chemical Society, the American Physical Society and the Materials Research Society. He serves as an editor for NANO, Composites Science and Technology, IEEE Transactions on Nanotechnology and the Journal of Nanoengineering and Nanosystems.

Ruoff co-founded nCarbon Inc., which focuses on ultracapacitors. Previously he co-founded Graphene Materials LLC. (now defunct).

####

For more information, please click here

Contacts:
Sandra Zaragoza

512-471-2129

Copyright © University of Texas at Austin

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Switching with molecules: Molecular switch will facilitate the development of pioneering electro-optical devices May 25th, 2018

Tunable diamond string may hold key to quantum memory: A process similar to guitar tuning improves storage time of quantum memory May 24th, 2018

Remote control of transport through nanopores: New study outlines key factors affecting the transfer of molecules through biological channels May 24th, 2018

2018 Kavli Prizes in Astrophysics, Nanoscience, and Neuroscience to be Announced Live on May 31: Live announcement at the Norwegian Academy of Science and Letters to be streamed live at World Science Festival Event May 24th, 2018

Graphene/ Graphite

Columbia Researchers Squeeze Light into Nanoscale Devices and Circuits: Team is first to directly image propagation and dynamics of graphene plasmons at very low temperatures; findings could impact optical communications and signal processing May 23rd, 2018

Strain improves performance of atomically thin semiconductor material May 11th, 2018

Nanoscale measurements 100x more precise, thanks to improved two-photon technique May 8th, 2018

Hematene joins parade of new 2D materials: Rice University-led team extracts 3-atom-thick sheets from common iron oxide May 8th, 2018

Thin films

Organic solar cells reach record efficiency, benchmark for commercialization April 23rd, 2018

High efficiency solar power conversion allowed by a novel composite material: A composite thin film developed at INRS improves significantly solar cells' power conversion efficiency April 10th, 2018

Researchers develop nanoparticle films for high-density data storage: April 3rd, 2018

Monocrystalline silicon thin film for cost-cutting solar cells with 10-times faster growth rate fabricated: Controlling nano surface roughness of porous silicon March 20th, 2018

Govt.-Legislation/Regulation/Funding/Policy

Tunable diamond string may hold key to quantum memory: A process similar to guitar tuning improves storage time of quantum memory May 24th, 2018

Columbia Researchers Squeeze Light into Nanoscale Devices and Circuits: Team is first to directly image propagation and dynamics of graphene plasmons at very low temperatures; findings could impact optical communications and signal processing May 23rd, 2018

NIST Puts the Optical Microscope Under the Microscope to Achieve Atomic Accuracy May 22nd, 2018

Magnesium magnificent for plasmonic applications: Rice University, University of Cambridge synthesize and test nanoparticles of abundant material May 22nd, 2018

Discoveries

Switching with molecules: Molecular switch will facilitate the development of pioneering electro-optical devices May 25th, 2018

Tunable diamond string may hold key to quantum memory: A process similar to guitar tuning improves storage time of quantum memory May 24th, 2018

Remote control of transport through nanopores: New study outlines key factors affecting the transfer of molecules through biological channels May 24th, 2018

'Spooky action at a distance': Researchers develop module for quantum repeater May 23rd, 2018

Announcements

Switching with molecules: Molecular switch will facilitate the development of pioneering electro-optical devices May 25th, 2018

Tunable diamond string may hold key to quantum memory: A process similar to guitar tuning improves storage time of quantum memory May 24th, 2018

Remote control of transport through nanopores: New study outlines key factors affecting the transfer of molecules through biological channels May 24th, 2018

2018 Kavli Prizes in Astrophysics, Nanoscience, and Neuroscience to be Announced Live on May 31: Live announcement at the Norwegian Academy of Science and Letters to be streamed live at World Science Festival Event May 24th, 2018

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Switching with molecules: Molecular switch will facilitate the development of pioneering electro-optical devices May 25th, 2018

Tunable diamond string may hold key to quantum memory: A process similar to guitar tuning improves storage time of quantum memory May 24th, 2018

Remote control of transport through nanopores: New study outlines key factors affecting the transfer of molecules through biological channels May 24th, 2018

'Spooky action at a distance': Researchers develop module for quantum repeater May 23rd, 2018

Military

Tunable diamond string may hold key to quantum memory: A process similar to guitar tuning improves storage time of quantum memory May 24th, 2018

Columbia Researchers Squeeze Light into Nanoscale Devices and Circuits: Team is first to directly image propagation and dynamics of graphene plasmons at very low temperatures; findings could impact optical communications and signal processing May 23rd, 2018

Hematene joins parade of new 2D materials: Rice University-led team extracts 3-atom-thick sheets from common iron oxide May 8th, 2018

Engineered polymer membranes could be new option for water treatment May 6th, 2018

Research partnerships

Tunable diamond string may hold key to quantum memory: A process similar to guitar tuning improves storage time of quantum memory May 24th, 2018

NIST Puts the Optical Microscope Under the Microscope to Achieve Atomic Accuracy May 22nd, 2018

Deeper understanding of quantum chaos may be the key to quantum computers May 16th, 2018

Nanoscale measurements 100x more precise, thanks to improved two-photon technique May 8th, 2018

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project