Subscribe free to our newsletters via your
. 24/7 Space News .




CARBON WORLDS
New method of growing high-quality graphene promising for next-gen technology
by Staff Writers
Santa Barbara CA (SPX) Oct 26, 2011


UCSB researchers have successfully controlled the growth of a high-quality bilayer graphene on a copper substrate using a method called chemical vapor deposition (CVD), which breaks down molecules of methane gas to build graphene sheets with carbon atoms. Credit: Peter Allen.

Making waves as the material that will revolutionize electronics, graphene - composed of a single layer of Carbon atoms - has nonetheless been challenging to produce in a way that will be practical for innovative electronics applications. Researchers at UC Santa Barbara have discovered a method to synthesize high quality graphene in a controlled manner that may pave the way for next-generation electronics application.

Kaustav Banerjee, a professor with the Electrical and Computer Engineering department and Director of the Nanoelectronics Research Lab at UCSB that has been studying carbon nanomaterials for more than seven years, led the research team to perfect methods of growing sheets of graphene, as detailed in a study to be published in the November 2011 issue of the journal Carbon.

"Our process has certain unique advantages that give rise to high quality graphene," says Banerjee. "For the electronics industry to effectively use graphene, it must first be grown selectively and in larger sheets. We have developed a synthesis technique that yields high- quality and high-uniformity graphene that can be translated into a scalable process for industry applications."

Using adhesive tape to lift flakes of graphene from graphite, University of Manchester researchers Geim and Novoselov were awarded the 2010 Nobel Prize in Physics for their pioneering isolation and characterization of the material. To launch graphene into futuristic applications, however, researchers have been seeking a controlled and efficient way to grow a higher quality of this single-atom-thick material in larger areas.

The discovery by UCSB researchers turns graphene production into an industry-friendly process by improving the quality and uniformity of graphene using efficient and reproducible methods. They were able to control the number of graphene layers produced - from mono-layer to bi-layer graphene - an important distinction for future applications in electronics and other technology.

"Intel has a keen interest in graphene due to many possibilities it holds for the next generation of energy- efficient computing, but there are many roadblocks along the way," added Intel Fellow, Shekhar Borkar. "The scalable synthesis technique developed by Professor Banerjee's group at UCSB is an important step forward."

As a material, graphene is the thinnest and strongest in the world - more than 100 times stronger than diamond - and is capable of acting as an ultimate conductor at room temperature. If it can be produced effectively, graphene's properties make it ideal for advancements in green electronics, super strong materials, and medical technology.

Graphene could be used to make flexible screens and electronic devices, computers with 1,000 GHz processors that run on virtually no energy, and ultra-efficient solar power cells.

Key to the UCSB team's discovery is their understanding of graphene growth kinetics under the influence of the substrate. Their approach uses a method called low pressure chemical vapor deposition (LPCVD) and involves disintegrating the hydrocarbon gas methane at a specific high temperature to build uniform layers of carbon (as graphene) on a pretreated copper substrate.

Banerjee's research group established a set of techniques that optimized the uniformity and quality of graphene, while controlling the number of graphene layers they grew on their substrate.

According to Dr. Wei Liu, a post-doctoral researcher and co-author of the study, "Graphene growth is strongly affected by imperfection sites on the copper substrate. By proper treatment of the copper surface and precise selection of the growth parameters, the quality and uniformity of graphene are significantly improved and the number of graphene layers can be controlled."

Professor Banerjee and credited authors Wei Liu, Hong Li, Chuan Xu and Yasin Khatami are not the first research team to make graphene using the CVD method, but they are the first to successfully refine critical methods to grow a high quality of graphene. In the past, a key challenge for the CVD method has been that it yields a lower quality of graphene in terms of carrier mobility - or how well it conducts electrons.

"Our graphene exhibits the highest reported field-effect mobility to date for CVD graphene, having an average value of 4000 cm2/V.s with the highest peak value at 5500 cm2/V.s.

This is an extremely high value compared with the mobility of silicon." added Hong Li, a Ph.D. candidate in Banerjee's research group.

"Kaustav Banerjee's group is leading graphene nanoelectronics research efforts at UCSB, from material synthesis to device design and circuit exploration. His work has provided our campus with unique and very powerful capabilities," added David Awschalom, Professor of Physics, Electrical and Computer Engineering, and Director of the California NanoSystems Institute (CNSI) at UCSB where Banerjee's laboratory is located.

"This new facility has also boosted our opportunities for collaborations across various science and engineering disciplines."

"There is no doubt graphene is a superior material. Intrinsically it is amazing," says Banerjee. "It is up to us, the scientists and engineers, to show how we can use graphene and harness its capabilities. There are challenges in how to grow it, how to transfer or not to transfer and pattern it, and how to tailor its properties for specific applications. But these challenges are fertile grounds for exciting research in the future."

.


Related Links
University of California - Santa Barbara
Carbon Worlds - where graphite, diamond, amorphous, fullerenes meet






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





CARBON WORLDS
Giant flakes make graphene oxide gel
Houston TX (SPX) Oct 24, 2011
Giant flakes of graphene oxide in water aggregate like a stack of pancakes, but infinitely thinner, and in the process gain characteristics that materials scientists may find delicious. A new paper by scientists at Rice University and the University of Colorado details how slices of graphene, the single-atom form of carbon, in a solution arrange themselves to form a nematic liquid crystal ... read more


CARBON WORLDS
Lunar Probe to search for water on Moon

Subtly Shaded Map of Moon Reveals Titanium Treasure Troves

NASA's Moon Twins Going Their Own Way

Titanium treasure found on Moon

CARBON WORLDS
Opportunity Past 21 Miles of Driving! Will Spend Winter at Cape York

Scientists develope new way to determine when water was present on Mars and Earth

Mars Rover Carries Device for Underground Scouting

Mars Landing-Site Specialist

CARBON WORLDS
NASA evacuates astronauts from deep-sea training

Is Your Space Elevator Going Up

Space tourism gaining momentum

NASA Veteran Alan Stern to Lead Florida Space Institute

CARBON WORLDS
China plans space lab docking

Living on Tiangong

Thousands of dreams to fly on Shenzhou 8

China's first space lab module in good condition

CARBON WORLDS
Russian Space Agency names next crew to ISS

ISS orbit readjusted by 3 km

Expedition 30 to ISS could be launched on Dec 21

ISS could be used for satellite assembly until 2028

CARBON WORLDS
Weather Favorable for NPP Launch

Vega arrives at French Guiana in preparation for its January 26 inaugural launch

SpaceX Completes Key Milestone to Fly Astronauts to International Space Station

ILS Proton Launches ViaSat-1 for ViaSat

CARBON WORLDS
Herschel Finds Oceans of Water in Disk of Nearby Star

UH Astronomer Finds Planet in the Process of Forming

Nearby planet-forming disk holds water for thousands of oceans

Herschel discovers tip of cosmic iceberg around nearby young star

CARBON WORLDS
RIM stock suffers on new tablet software stall

Wearable depth-sensing projection system makes any surface capable of multitouch interaction

ROSAT re-entered atmosphere over Bay of Bengal

The eyes have it: Computer-inspired creativity




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement