Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Silicon superlattices: New waves in thermoelectricity

Max G. Lagally
Max G. Lagally

Abstract:
University of Wisconsin-Madison research team has developed a new method for using nanoscale silicon that could improve devices that convert thermal energy into electrical energy.

Silicon superlattices: New waves in thermoelectricity

Madison, WI | Posted on March 31st, 2009

The team, led by Erwin W. Mueller Professor and Bascom Professor of Surface Science Max Lagally, published its findings in the March 24 issue of the journal ACS Nano.

Thermoelectric devices can use electricity to cool, or conversely convert heat to electricity. To improve efficiency in tiny thermoelectric devices, researchers build superlattices of alternating thin layers of two different semiconductor materials, called heterojunctions. Charges in multi-layer heterojunction wires travel through a periodic electric field that influences their motion; however, it is difficult to create modulation large enough to be effective with traditional heterojunctions, Lagally says.

The UW-Madison team addressed the problem by creating a superlattice from a single material: a sheet of silicon nanometers thick, called a nanomembrane, and cutting it into ribbons nanometers wide. The researchers can induce localized strain in the silicon, creating an effective strain wave that causes charges the electric field in the ribbon to vary periodically.

"Essentially we're making the equivalent of a heterojunction superlattice with one material," says Lagally, whose home department is materials science and engineering. "We're actually doing better with these strained regions than you can do easily with multiple-chemical-component systems."

The strained-silicon superlattices display greater electric field modulation than their heterojunction counterparts, so they may improve silicon thermoelectrics near or above room temperature. In addition, they are relatively easy to manufacture. Lagally and his group theorize that their method could apply to any type of semiconductor nanomembrane.

"It's cool in several ways: It's a single material, the modulation in the electric field is bigger than what others can make easily, and it's very straightforward," says Lagally.

Co-authors of the paper include Lagally, UW-Madison postdoctoral associate Hing-Huang Huang, graduate students Clark Ritz and Bozidar Novakovic, assistant scientist Frank Flack, associate scientist Don Savage, Materials Science and Engineering Associate Professor Paul Evans, and Electrical and Computer Engineering Assistant Professor Irena Knezevic, along with Decai Yu, Yu Zhang and Professor Feng Liu of the University of Utah.

The U.S. Department of Energy, the National Science Foundation and the Air Force Office of Scientific Research supported this work.

####

For more information, please click here

Copyright © University of Wisconsin-Madison

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

Bosch announces high-performance MEMS acceleration sensors for wearables June 27th, 2017

Nanometrics to Participate in the 9th Annual CEO Investor Summit 2017: Accredited investor and publishing research analyst event held concurrently with SEMICON West and Intersolar 2017 in San Francisco June 27th, 2017

NMRC, University of Nottingham chooses the Quorum Q150 coater for its reliable and reproducible film thickness when coating samples with iridium June 27th, 2017

Picosunís ALD solutions enable novel high-speed memories June 27th, 2017

Possible Futures

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Research accelerates quest for quicker, longer-lasting electronics: UC Riverside-led research makes topological insulators magnetic well above room temperatures June 25th, 2017

U.S. Air Force Research Lab Taps IBM to Build Brain-Inspired AI Supercomputing System: Equal to 64 million neurons, new neurosynaptic supercomputing system will power complex AI tasks at unprecedented speed and energy efficiency June 23rd, 2017

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Announcements

Bosch announces high-performance MEMS acceleration sensors for wearables June 27th, 2017

Nanometrics to Participate in the 9th Annual CEO Investor Summit 2017: Accredited investor and publishing research analyst event held concurrently with SEMICON West and Intersolar 2017 in San Francisco June 27th, 2017

NMRC, University of Nottingham chooses the Quorum Q150 coater for its reliable and reproducible film thickness when coating samples with iridium June 27th, 2017

Picosunís ALD solutions enable novel high-speed memories June 27th, 2017

Energy

Tiny bubbles provide tremendous propulsion in new microparticles research-Ben-Gurion U. June 21st, 2017

Enhanced photocatalytic activity by Cu2O nanoparticles integrated H2Ti3O7 nanotubes June 21st, 2017

Cambridge Nanotherm partners with Inabata for global sales and distribution June 20th, 2017

Development of low-dimensional nanomaterials could revolutionize future technologies June 15th, 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