Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Carbon nanotubes may cheaply harvest sunlight

Michael Arnold
Michael Arnold

Abstract:
University of Wisconsin-Madison researchers are studying how to create inexpensive, efficient solar cells from carbon nanotubes, which are sheets of carbon rolled into seamless cylinders 1-nanometer in diameter. Many researchers are studying how to use nanotubes for mechanical and electronics applications, but Materials Science and Engineering Assistant Professor Michael Arnold is one of the first to apply them to solar energy.

Carbon nanotubes may cheaply harvest sunlight

Madison, WI | Posted on October 20th, 2009

"We are developing new materials and methods to create scalable, inexpensive, stable and efficient photovoltaic solar cell technologies," Arnold says. "Semiconducting carbon nanotubes have remarkable electronic and optical properties that are ideally suited for photovoltaics, so they are an interesting starting point."

Carbon is a promising choice for solar cells because it is an abundant, inexpensive element, and carbon nanotubes have excellent electrical conductivity and strong optical absorptivity. Most current solar cells use silicon, which converts 10 to 30 percent of sunlight absorbed into electricity. This is a good rate, but silicon cells are expensive.

"The cost is upfront for silicon cells, and the cost per kilowatt-hour is five times more than you'd pay for coal over 20 years — that's not very motivating for people," says Arnold. With carbon nanotubes, he hopes to achieve efficiency comparable to silicon solar cells for less cost.

Arnold says solar is a valuable energy source since the sun outputs approximately 1,000 watts per square yard. A solar cell that is only 20 percent efficient would generate about 200 watts per square yard on a sunny day, so coating the roof of an average 40-square-yard house with solar cells would make a significant dent in the average energy needs of the household. To have an effect on the national electric grid, Arnold envisions expansive fields of solar cells built in desert regions.

"Solar is a viable technology for producing energy," Arnold says. "It's just too expensive right now."

To create the new carbon nanotube solar cells, Arnold and his students grow nanotube structures and then separate the useful semiconducting nanotubes from undesirable metallic ones. They also separate the tubes according to diameter, which determines a particular nanotube's bandgap, or wavelength of light the tube can absorb. Certain bandgaps are more suitable than others for absorbing sunlight.

After sorting out the useful nanotubes, the team wraps them in a semiconducting polymer to make the tubes soluble. They turn the combined nanotubes and polymer into a solution, which can be sprayed in a thin film onto transparent indium-tin-oxide coated glass substrates. The researchers then deposit an electron-accepting semiconductor and a negative electrode on top of the nanotubes to complete the entire cell.

In creating the new solar cells, Arnold, who is funded by the National Science Foundation, is attempting to answer a variety of fundamental science and research questions. He is studying how charge is generated in the nanotubes in response to light and how different electron-accepting materials affect the efficiency and speed of the separation of that charge.

"The driving question is, can we understand how to both process the tubes to get the morphology we want, and can we also learn how light creates charges in our carbon nanotube materials and how these charges separate?" he says.

####

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

GLOBALFOUNDRIES Announces Availability of 45nm RF SOI to Advance 5G Mobile Communications: Optimized RF features deliver high-performance solutions for mmWave beam forming applications in 5G smartphones and base stations February 22nd, 2017

EmTech Asia breaks new barriers with potential applications of space exploration with NASA and MIT February 22nd, 2017

JPK selects compact tensile stage from Deben for their NanoWizard® AFM platform to broaden capabilities for materials characterisation February 22nd, 2017

Molecular phenomenon discovered by advanced NMR facility: Cutting edge technology has shown a molecule self-assembling into different forms when passing between solution state to solid state, and back again - a curious phenomenon in science - says research by the University of Wa February 22nd, 2017

Discoveries

Molecular phenomenon discovered by advanced NMR facility: Cutting edge technology has shown a molecule self-assembling into different forms when passing between solution state to solid state, and back again - a curious phenomenon in science - says research by the University of Wa February 22nd, 2017

Tiny nanoclusters could solve big problems for lithium-ion batteries February 21st, 2017

Oxford Instruments announces Dr Brad Ramshaw of Cornell University, as winner of the 2017 Lee Osheroff Richardson Science Prize February 20th, 2017

Breakthrough with a chain of gold atoms: In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport February 20th, 2017

Announcements

GLOBALFOUNDRIES Announces Availability of 45nm RF SOI to Advance 5G Mobile Communications: Optimized RF features deliver high-performance solutions for mmWave beam forming applications in 5G smartphones and base stations February 22nd, 2017

EmTech Asia breaks new barriers with potential applications of space exploration with NASA and MIT February 22nd, 2017

JPK selects compact tensile stage from Deben for their NanoWizard® AFM platform to broaden capabilities for materials characterisation February 22nd, 2017

Molecular phenomenon discovered by advanced NMR facility: Cutting edge technology has shown a molecule self-assembling into different forms when passing between solution state to solid state, and back again - a curious phenomenon in science - says research by the University of Wa February 22nd, 2017

Energy

Strem Chemicals and Dotz Nano Ltd. Sign Distribution Agreement for Graphene Quantum Dots Collaboration February 21st, 2017

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

In-cell molecular sieve from protein crystal February 14th, 2017

NREL research pinpoints promise of polycrystalline perovskites February 8th, 2017

Solar/Photovoltaic

Strem Chemicals and Dotz Nano Ltd. Sign Distribution Agreement for Graphene Quantum Dots Collaboration February 21st, 2017

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

Material can turn sunlight, heat and movement into electricity -- all at once: Extracting energy from multiple sources could help power wearable technology February 9th, 2017

NREL research pinpoints promise of polycrystalline perovskites February 8th, 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