Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Layer upon layer: Method holds promise for making two- or three-tier graphene films that could be used for new electronic devices

When compounds of bromine or chlorine (represented in blue) are introduced into a block of graphite (shown in green), the atoms find their way into the structure in between every third sheet, thus increasing the spacing between those sheets and making it easier to split them apart.
Image: Chih-Jen Shih/Christine Daniloff
When compounds of bromine or chlorine (represented in blue) are introduced into a block of graphite (shown in green), the atoms find their way into the structure in between every third sheet, thus increasing the spacing between those sheets and making it easier to split them apart.
Image: Chih-Jen Shih/Christine Daniloff

Abstract:
Graphene, a form of pure carbon arranged in a lattice just one atom thick, has interested countless researchers with its unique strength and its electrical and thermal conductivity. But one key property it lacks which would make it suitable for a plethora of new uses is the ability to form a band gap, needed for devices such as transistors, computer chips and solar cells.

Layer upon layer: Method holds promise for making two- or three-tier graphene films that could be used for new electronic devices

Cambridge, MA | Posted on June 29th, 2011

Now, a team of MIT scientists has found a way to produce graphene in significant quantities in a two- or three-layer form. When the layers are arranged just right, these structures give graphene the much-desired band gap an energy range that falls between the bands, or energy levels, where electrons can exist in a given material.

"It's a breakthrough in graphene technology," says Michael Strano, the Charles and Hilda Roddey Associate Professor of Chemical Engineering at MIT. The new work is described in a paper published this week in the journal Nature Nanotechnology, co-authored by graduate student Chih-Jen Shih, Professor of Chemical Engineering Daniel Blankschtein, Strano and 10 other students and postdocs.

Graphene was first proven to exist in 2004 (a feat that led to the 2010 Nobel Prize in physics), but making it in quantities large enough for anything but small-scale laboratory research has been a challenge. The standard method remains using adhesive tape to pick up tiny flakes of graphene from a block of highly purified graphite (the material of pencil lead) a technique that does not lend itself to commercial-scale production.

The new method, however, can be carried out at a scale that opens up the possibility of real, practical applications, Strano says, and makes it possible to produce the precise arrangement of the layers called A-B stacked, with the atoms in one layer centered over the spaces between atoms in the next that yields desirable electronic properties.

"If you want a whole lot of bilayers that are A-B stacked, this is the only way to do it," he says.

The trick takes advantage of a technique originally developed as far back as the 1950s and '60s by MIT Institute Professor Mildred Dresselhaus, among others: Compounds of bromine or chlorine introduced into a block of graphite naturally find their way into the structure of the material, inserting themselves regularly between every other layer, or in some cases every third layer, and pushing the layers slightly farther apart in the process. Strano and his team found that when the graphite is dissolved, it naturally comes apart where the added atoms lie, forming graphene flakes two or three layers thick.

"Because this dispersion process can be very gentle, we end up with much larger flakes" than anyone has made using other methods, Strano says. "Graphene is a very fragile material, so it requires gentle processing."

Such formations are "one of the most promising candidates for post-silicon nanoelectronics," the authors say in their paper. The flakes produced by this method, as large as 50 square micrometers in area, are large enough to be useful for electronic applications, they say. To prove the point, they were able to manufacture some simple transistors on the material.

The material can now be used to explore the development of new kinds of electronic and optoelectronic devices, Strano says. And unlike the "Scotch tape" approach to making graphene, "our approach is industrially relevant," Strano says.

James Tour, a professor of chemistry and of mechanical engineering and materials science at Rice University, who was not involved in this research, says the work involved "brilliant experiments" that produced convincing statistics. He added that further work would be needed to improve the yield of usable graphene material in their solutions, now at about 35 to 40 percent, to more than 90 percent. But once that is achieved, he says, "this solution-phase method could dramatically lower the cost of these unique materials and speed the commercialization of them in applications such as optical electronics and conductive composites."

While it's hard to predict how long it will take to develop this method to the point of commercial applications, Strano says, "it's coming about at a breakneck pace." A similar solvent-based method for making single-layer graphene is already being used to manufacture some flat-screen television sets, and "this is definitely a big step" toward making bilayer or trilayer devices, he says.

The work was supported by grants from the U.S. Office of Naval Research through a multi-university initiative that includes Harvard University and Boston University along with MIT, as well as from the Dupont/MIT Alliance, a David H. Koch fellowship, and the Army Research Office through the Institute for Soldier Nanotechnologies at MIT.

####

For more information, please click here

Contacts:
77 Massachusetts Avenue, Room 11-400
Cambridge, MA 02139-4307
617.253.2700
TTY 617.258.9344

Copyright © MIT

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

Proving nanoparticles in sunscreen products August 4th, 2015

Global Carbon Nanotubes Industry 2015: Acute Market Reports August 4th, 2015

Nanoparticles Give Antibacterial Properties to Machine-Woven Carpets August 4th, 2015

Diagnosis of Salmonella Bacterium-Caused Food Poisoning by Biosensors August 3rd, 2015

Thin films offer promise for ferroelectric devices: Researchers at Tokyo Institute of Technology demystify the ferroelectric properties observed in hafnium-oxide-based thin films, revealing a potentially useful device material August 3rd, 2015

Graphene

Better together: Graphene-nanotube hybrid switches August 3rd, 2015

This could replace your silicon computer chips: A new semiconductor material made from black phosphorus may be a candidate to replace silicon in future tech July 30th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Small tilt in magnets makes them viable memory chips August 3rd, 2015

Vaccine with virus-like nanoparticles effective treatment for RSV, study finds August 3rd, 2015

MIPT researchers clear the way for fast plasmonic chips August 3rd, 2015

Nanoparticles used to breach mucus barrier in lungs: Proof-of-concept study conducted in mice a key step toward better treatments for lung diseases August 3rd, 2015

Chip Technology

Small tilt in magnets makes them viable memory chips August 3rd, 2015

Better together: Graphene-nanotube hybrid switches August 3rd, 2015

MIPT researchers clear the way for fast plasmonic chips August 3rd, 2015

Thin films offer promise for ferroelectric devices: Researchers at Tokyo Institute of Technology demystify the ferroelectric properties observed in hafnium-oxide-based thin films, revealing a potentially useful device material August 3rd, 2015

Discoveries

Proving nanoparticles in sunscreen products August 4th, 2015

Nanoparticles Give Antibacterial Properties to Machine-Woven Carpets August 4th, 2015

Small tilt in magnets makes them viable memory chips August 3rd, 2015

Better together: Graphene-nanotube hybrid switches August 3rd, 2015

Announcements

Proving nanoparticles in sunscreen products August 4th, 2015

Global Carbon Nanotubes Industry 2015: Acute Market Reports August 4th, 2015

Nanoparticles Give Antibacterial Properties to Machine-Woven Carpets August 4th, 2015

Diagnosis of Salmonella Bacterium-Caused Food Poisoning by Biosensors August 3rd, 2015

Military

Self-assembling, biomimetic membranes may aid water filtration August 1st, 2015

Take a trip through the brain July 30th, 2015

Sol-gel capacitor dielectric offers record-high energy storage July 30th, 2015

Reshaping the solar spectrum to turn light to electricity: UC Riverside researchers find a way to use the infrared region of the sun's spectrum to make solar cells more efficient July 27th, 2015

Energy

Transparent, electrically conductive network of encapsulated silver nanowires: A novel electrode for optoelectronics August 1st, 2015

Springer and Tsinghua University Press present the second Nano Research Award: Paul Alivisatos of the University of California Berkeley receives the honor for outstanding contributions in nanoscience July 30th, 2015

Controlling Dynamic Behavior of Carbon Nanosheets in Structures Made Possible July 30th, 2015

March 2016; 6th Int'l Conference on Nanostructures in Iran July 29th, 2015

Grants/Awards/Scholarships/Gifts/Contests/Honors/Records

Heating and cooling with light leads to ultrafast DNA diagnostics July 31st, 2015

Springer and Tsinghua University Press present the second Nano Research Award: Paul Alivisatos of the University of California Berkeley receives the honor for outstanding contributions in nanoscience July 30th, 2015

European Technology Platform for Nanomedicine and ENATRANS European Consortium Launch the 2nd edition of the Nanomedicine Award: The Award to be presented at BIO-Europe conference in Munich, November 2015 July 30th, 2015

Publication on Atomic Force Microscopy based nanoscale IR Spectroscopy (AFM-IR) persists as a 2015 top downloaded paper July 29th, 2015

Research partnerships

University of Puerto Rico announces August 11th as the launch date for their NASA mission to look for life in space XEI reports August 3rd, 2015

Newly-Developed Polymers Control Size of Nanoparticles during Production Process July 30th, 2015

Meet the high-performance single-molecule diode: Major milestone in molecular electronics scored by Berkeley Lab and Columbia University team July 29th, 2015

Spintronics: Molecules stabilizing magnetism: Organic molecules fixing the magnetic orientation of a cobalt surface/ building block for a compact and low-cost storage technology/ publication in Nature Materials July 25th, 2015

Solar/Photovoltaic

Transparent, electrically conductive network of encapsulated silver nanowires: A novel electrode for optoelectronics August 1st, 2015

Springer and Tsinghua University Press present the second Nano Research Award: Paul Alivisatos of the University of California Berkeley receives the honor for outstanding contributions in nanoscience July 30th, 2015

Reshaping the solar spectrum to turn light to electricity: UC Riverside researchers find a way to use the infrared region of the sun's spectrum to make solar cells more efficient July 27th, 2015

Rice University finding could lead to cheap, efficient metal-based solar cells: Plasmonics study suggests how to maximize production of 'hot electrons' July 22nd, 2015

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project