Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > NREL Nano-Technology Solar Cell Achieves 18.2% Efficiency: Breakthrough should eliminate need for anti-reflection layer, cutting costs

Abstract:
Scientists at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) have produced solar cells using nanotechnology techniques at an efficiency - 18.2% -- that is competitive. The breakthrough should be a major step toward helping lower the cost of solar energy.

NREL Nano-Technology Solar Cell Achieves 18.2% Efficiency: Breakthrough should eliminate need for anti-reflection layer, cutting costs

Golden, CO | Posted on October 12th, 2012

NREL tailored a nanostructured surface while ensuring that the light-generated electricity can still be collected efficiently from the solar cell. The researchers made nano-islands of silver on a silicon wafer and immersed it briefly in liquids to make billions of nano-sized holes in each square-inch of the silicon wafer surface. The holes and silicon walls are smaller than the light wavelengths hitting them, so the light doesn't recognize any sudden change in density at the surface and, thus, don't reflect back into the atmosphere as wasted energy. The researchers controlled the nanoshapes and the chemical composition of the surface to reach record solar cell efficiencies for this 'black silicon' material.

The paper, "An 18.2%-efficient black-silicon solar cell achieved through control of carrier recombination in nanostructures" by NREL's Jihun Oh, Hao-Chih Yuan, and Howard Branz, currently appears on Nature Nanotechnology's website.

Typically, solar cell manufacturers must add an extra anti-reflection layer, or two, to their cells, which boosts costs significantly.

NREL previously had demonstrated that their nanostructures reflected less light than the best anti-reflection layers of a solar cell. But until now, they hadn't been able to achieve overall efficiency with their black silicon cells that could approach the best marks for other silicon cells.

Oh, Yuan, and Branz, first had to determine why the increased surface area of the nanostructures dramatically reduced the collection of electricity and hurt the voltage and current of the cells.

Their experiments demonstrated that the high-surface area, and especially a process called Auger recombination, limit the collection of photons on most nanostructured solar cells. They concluded that this Auger recombination is caused when too many of the dopant impurities put in to make the cell work come through the nanostructured surface.

This scientific understanding enabled them to suppress Auger recombination with lighter and shallower doping. Combining this lighter doping with slightly smoother nanoshapes, they can build an 18.2%-efficient solar cell that is black but responds nearly ideally to almost the entire solar spectrum.

The Energy Department funded the research grant through the American Recovery and Reinvestment Act.

Branz, the grant's principal investigator, said, "This work can have a big impact on both conventional and emerging solar cell based on nanowires and nanospheres. For the first time it shows that really great solar cells can be made from nanostructured semiconductors."

Branz added, "The next challenges are to translate these results to common industrial practice and then get the efficiency over 20%. After that, I hope to see these kinds of nanostructuring techniques used on far thinner cells to use less semiconductor material."

"Now we have a clear study that shows how optimizing the surface area and the doping together can give better efficiency," Yuan said. "The surface area and the doping concentration near the surface affect nano-structured solar-cell performance."

First author, Oh, an NREL Postdoctoral Fellow said the NREL study "clearly shows that the right combination of a carefully nano-structured surface and good processing can reduce the cost while cutting unwanted reflection of sunlight."

####

About National Renewable Energy Laboratory (NREL)
NREL is the U.S. Department of Energy's primary national laboratory for renewable energy and energy efficiency research and development. NREL is operated for DOE by the Alliance for Sustainable Energy, LLC.

For more information, please click here

Contacts:
William Scanlon
303-275-4051

Copyright © National Renewable Energy Laboratory (NREL)

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 Links

Download paper - "An 18.2%-efficient black-silicon solar cell achieved through control of carrier recombination in nanostructures.":

Related News Press

Laboratories

Sandia use confined nanoparticles to improve hydrogen storage materials performance: Big changes from a small package for hydrogen storage February 25th, 2017

News and information

Sandia use confined nanoparticles to improve hydrogen storage materials performance: Big changes from a small package for hydrogen storage February 25th, 2017

New nano approach could cut dose of leading HIV treatment in half February 24th, 2017

Atom-scale oxidation mechanism of nanoparticles helps develop anti-corrosion materials February 24th, 2017

Atomic force imaging used to study nematodes: KFU bionanotechnology lab (head - Dr. Rawil Fakhrullin) has obtained 3-D images of nematodes' cuticles February 23rd, 2017

Govt.-Legislation/Regulation/Funding/Policy

Sandia use confined nanoparticles to improve hydrogen storage materials performance: Big changes from a small package for hydrogen storage February 25th, 2017

Atom-scale oxidation mechanism of nanoparticles helps develop anti-corrosion materials February 24th, 2017

Atomic force imaging used to study nematodes: KFU bionanotechnology lab (head - Dr. Rawil Fakhrullin) has obtained 3-D images of nematodes' cuticles February 23rd, 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

Sandia use confined nanoparticles to improve hydrogen storage materials performance: Big changes from a small package for hydrogen storage February 25th, 2017

New nano approach could cut dose of leading HIV treatment in half February 24th, 2017

Atom-scale oxidation mechanism of nanoparticles helps develop anti-corrosion materials February 24th, 2017

Atomic force imaging used to study nematodes: KFU bionanotechnology lab (head - Dr. Rawil Fakhrullin) has obtained 3-D images of nematodes' cuticles February 23rd, 2017

Announcements

Sandia use confined nanoparticles to improve hydrogen storage materials performance: Big changes from a small package for hydrogen storage February 25th, 2017

New nano approach could cut dose of leading HIV treatment in half February 24th, 2017

Atom-scale oxidation mechanism of nanoparticles helps develop anti-corrosion materials February 24th, 2017

Atomic force imaging used to study nematodes: KFU bionanotechnology lab (head - Dr. Rawil Fakhrullin) has obtained 3-D images of nematodes' cuticles February 23rd, 2017

Energy

Sandia use confined nanoparticles to improve hydrogen storage materials performance: Big changes from a small package for hydrogen storage February 25th, 2017

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

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