Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > 'Tuning' Graphene Drums Might Turn Conductors to Semiconductors

NIST researchers showed that straining graphene membrane creates pseudomagnetic fields that confines the graphene's electrons and creates quantized quantum dot-like energy levels. The background is a false color image of the graphene drumheads made from a single layer of graphene over 1 micron-sized pits etched in a silicon dioxide substrate.
Credit: N. Klimov and T. Li, NIST/UMD
NIST researchers showed that straining graphene membrane creates pseudomagnetic fields that confines the graphene's electrons and creates quantized quantum dot-like energy levels. The background is a false color image of the graphene drumheads made from a single layer of graphene over 1 micron-sized pits etched in a silicon dioxide substrate.

Credit: N. Klimov and T. Li, NIST/UMD

Abstract:
Tightening or relaxing the tension on a drumhead will change the way the drum sounds. The same goes for drumheads made from graphene, only instead of changing the sound, stretching graphene dramatically alters the material's electrical properties. Researchers working at the National Institute of Standards and Technology (NIST) and the University of Maryland have shown* that subjecting graphene to mechanical strain can mimic the effects of magnetic fields and create a quantum dot, an exotic type of semiconductor with a wide range of potential uses in electronic devices.

'Tuning' Graphene Drums Might Turn Conductors to Semiconductors

Gaithersburg, MD | Posted on June 28th, 2012

Graphene is a single layer of carbon atoms arranged in a honeycomb lattice. Pure graphene is a phenomenal conductor, transmitting electricity with little resistance at room temperature. But microelectronic devices depend on semiconductors that can be turned "on" and "off" because they have an energetic threshold beneath which they won't conduct electricity. This new work demonstrates that mechanical strain can be used to make tiny regions of graphite act like a classic semiconductor.

The research team suspended a sheet of graphene over shallow holes in a substrate of silicon dioxide—essentially making a set of graphene drumheads. In probing the drumheads with a scanning probe microscope, they found that the graphene rose up to meet the tip of the microscope— a result of the van der Waals force, a weak electrical force that creates attraction between objects that are very close to each other. Calculations by the University of Maryland group showed that the graphene should stretch into a peak, like the top of a circus tent.

The researchers discovered that they could tune the strain in the drumhead using the conducting plate upon which the graphene and substrate were mounted to create a countervailing attraction and pull the drumhead down. In this way, they could pull the graphene into or out of the hole below it.

Their measurements showed that changing the degree of strain changed the material's electrical properties. When they pulled the graphene membrane into the tent-like shape, the region at the apex acted just like a quantum dot, a type of semiconductor in which electrons are confined to a small region of space.

"Normally, to make a graphene quantum dot, you would have to cut out a nanosize piece of graphene," says NIST fellow Joseph Stroscio. "Our work shows that you can achieve the same thing with strain-induced pseudomagnetic fields. It's a great result, and a significant step toward developing future graphene-based devices."

More details are available in the June 21 NIST news announcement, "Graphene Drumheads Tuned to Make Quantum Dots" at www.nist.gov/cnst/drumheads_062112.cfm.

The work was a collaborative effort with the University of Maryland, College Park, and the Korea Research Institute of Standards and Science.

* N. Klimov, S. Jung, S. Zhu, T. Li, C. Wright, S. Solares, D. Newell, N. Zhitenev and J. Stroscio. Electromechanical properties of graphene drumheads. Science. Vol. 336 no. 6088 pp. 1557-1561 DOI: 10.1126/science.1220335. Published online before print June 21, 2012.

####

About National Institute of Standards and Technology (NIST)
The National Institute of Standards and Technology (NIST) is an agency of the U.S. Department of Commerce.

For more information, please click here

Contacts:
Mark Esser
301-975-8735

Copyright © National Institute of Standards and Technology (NIST)

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

DNA triggers shape-shifting in hydrogels, opening a new way to make 'soft robots' September 21st, 2017

Physicists develop new recipes for design of fast single-photon gun Physicists develop high-speed single-photon sources for quantum computers of the future September 21st, 2017

GLOBALFOUNDRIES Announces Availability of mmWave and RF/Analog on Leading FDX™ FD-SOI Technology Platform: Technology solution delivers ‘connected intelligence’ to next generation high-volume wireless and IoT applications with lower power and significantly reduced cost September 20th, 2017

GLOBALFOUNDRIES Announces Availability of Embedded MRAM on Leading 22FDX® FD-SOI Platform: Advanced embedded non-volatile memory solution delivers ‘connected intelligence’ by expanding SoC capabilities on the 22nm process node September 20th, 2017

Laboratories

Copper catalyst yields high efficiency CO2-to-fuels conversion: Berkeley Lab scientists discover critical role of nanoparticle transformation September 20th, 2017

Solar-to-fuel system recycles CO2 to make ethanol and ethylene: Berkeley Lab advance is first demonstration of efficient, light-powered production of fuel via artificial photosynthesis September 19th, 2017

New insights into nanocrystal growth in liquid: Understanding process that creates complex crystals important for energy applications September 14th, 2017

Graphene/ Graphite

New quantum phenomena in graphene superlattices September 18th, 2017

Graphene based terahertz absorbers: Printable graphene inks enable ultrafast lasers in the terahertz range September 13th, 2017

UConn chemist synthesizes pure graphene August 30th, 2017

Govt.-Legislation/Regulation/Funding/Policy

DNA triggers shape-shifting in hydrogels, opening a new way to make 'soft robots' September 21st, 2017

Copper catalyst yields high efficiency CO2-to-fuels conversion: Berkeley Lab scientists discover critical role of nanoparticle transformation September 20th, 2017

Solar-to-fuel system recycles CO2 to make ethanol and ethylene: Berkeley Lab advance is first demonstration of efficient, light-powered production of fuel via artificial photosynthesis September 19th, 2017

New insights into nanocrystal growth in liquid: Understanding process that creates complex crystals important for energy applications September 14th, 2017

Chip Technology

Physicists develop new recipes for design of fast single-photon gun Physicists develop high-speed single-photon sources for quantum computers of the future September 21st, 2017

GLOBALFOUNDRIES Delivers 8SW RF SOI Technology for Next-Generation Mobile and 5G Applications: Advanced 8SW 300mm SOI technology enables cost-effective, high-performance RF front-end modules for 4G LTE mobile and sub-6GHz 5G applications September 20th, 2017

GLOBALFOUNDRIES Unveils Vision and Roadmap for Next-Generation 5G Applications: Technology platforms are uniquely positioned to enable a new era of ‘connected intelligence’ with the transition to 5G September 20th, 2017

GLOBALFOUNDRIES Delivers Custom 14nm FinFET Technology for IBM Systems: Jointly developed 14HP process is world’s only technology that leverages both FinFET and SOI September 20th, 2017

Discoveries

DNA triggers shape-shifting in hydrogels, opening a new way to make 'soft robots' September 21st, 2017

Physicists develop new recipes for design of fast single-photon gun Physicists develop high-speed single-photon sources for quantum computers of the future September 21st, 2017

Copper catalyst yields high efficiency CO2-to-fuels conversion: Berkeley Lab scientists discover critical role of nanoparticle transformation September 20th, 2017

Solar-to-fuel system recycles CO2 to make ethanol and ethylene: Berkeley Lab advance is first demonstration of efficient, light-powered production of fuel via artificial photosynthesis September 19th, 2017

Announcements

DNA triggers shape-shifting in hydrogels, opening a new way to make 'soft robots' September 21st, 2017

Physicists develop new recipes for design of fast single-photon gun Physicists develop high-speed single-photon sources for quantum computers of the future September 21st, 2017

GLOBALFOUNDRIES Introduces New 12nm FinFET Technology for High-Performance Applications September 20th, 2017

Copper catalyst yields high efficiency CO2-to-fuels conversion: Berkeley Lab scientists discover critical role of nanoparticle transformation September 20th, 2017

Quantum Dots/Rods

New approach on research and design for CQD catalysts in World Scientific NANO August 2nd, 2017

Coupling a nano-trumpet with a quantum dot enables precise position determination July 14th, 2017

Graphene and quantum dots put in motion a CMOS-integrated camera that can see the invisible May 29th, 2017

The brighter side of twisted polymers: Conjugated polymers designed with a twist produce tiny, brightly fluorescent particles with broad applications May 16th, 2017

Research partnerships

GLOBALFOUNDRIES Delivers Custom 14nm FinFET Technology for IBM Systems: Jointly developed 14HP process is world’s only technology that leverages both FinFET and SOI September 20th, 2017

Solar-to-fuel system recycles CO2 to make ethanol and ethylene: Berkeley Lab advance is first demonstration of efficient, light-powered production of fuel via artificial photosynthesis September 19th, 2017

A new approach to ultrafast light pulses: Unusual fluorescent materials could be used for rapid light-based communications systems September 19th, 2017

New insights into nanocrystal growth in liquid: Understanding process that creates complex crystals important for energy applications September 14th, 2017

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