Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Silver Nanoparticles Give Polymer Solar Cells A Boost

07.10.2009
Small bits of metal may play a new role in solar power.

Researchers at Ohio State University are experimenting with polymer semiconductors that absorb the sun’s energy and generate electricity. The goal: lighter, cheaper, and more-flexible solar cells.

They have now discovered that adding tiny bits of silver to the plastic boosts the materials’ electrical current generation.

Paul Berger, professor of electrical and computer engineering and professor of physics at Ohio State, led the team that reported the results online in the journal Solar Energy Materials and Solar Cells.

Berger and his team measured the amount of light absorbed and the current density -- the amount of electrical current generated per square centimeter -- generated by an experimental solar cell polymer with and without silver nano-particles.

Without silver, the material generated 6.2 milli-amps per square centimeter. With silver, it generated 7.0 -- an increase of almost 12 percent.

The small silver particles help the polymer capture a wider range of wavelengths of sunlight than would normally be possible, which in turn increases the current output, Berger explained.

He added that with further work, this technology could go a long way toward making polymer solar cells commercially viable.

“The light absorption of polymer solar cells is inadequate today,” he said. “The top-performing materials have an overall efficiency of about 5 percent. Even with the relatively low production cost of polymers compared to other solar cell materials, you’d still have to boost that efficiency to at least 10 percent to turn a profit. One way to do that would be to expand the range of wavelengths that they absorb. Current polymers only absorb a small portion of the incident sunlight.”

The new fabrication technique involves encasing each silver particle in an ultra-thin polymer layer -- a different polymer than the light-absorbing polymer that makes up the solar cell -- before depositing them below the light-absorbing polymer; the coating prevents the silver particles from clumping, but also allows them to self-assemble into a dense and regular mosaic pattern that Berger believes is key to enhancing the light absorption.

Even though the silver particles allow the material to produce 12 percent more electrical current, that improvement may not translate directly into a 12 percent increase in overall solar cell efficiency. Many factors effect efficiency, and some energy can be lost.

Still, the silver nanoparticles could boost the overall efficiency of virtually any kind of solar cell -- those made from polymers or other semiconductor materials. Berger and his colleagues are now studying other nanoparticle formulations that would increase that number further.

“By changing the organic coating, we could change the spacing of the particles and alter the size of each particle. By fine-tuning the mosaic pattern, we could move the enhanced absorption to different wavelengths, and thus get even more of an improvement. I think we can get several percent more,” he said.

The semiconductor polymer captures more light because the metal nanoparticles absorb light that would normally be wasted. This extra light energy excites electrons in the metal particles, creating electron waves called plasmons -- a cross between plasma and photons. The plasmons dance across the surface, depositing energy inside the solar cell that would otherwise be lost.

Researchers have been looking for a way to generate plasmons in solar cells without greatly increasing the difficulty and cost of manufacture. Given that his technique uses simple fabrication equipment at room temperature, and given that the silver particles self-assemble based only on the chemistry of the coating, Berger feels that any laboratory could easily make use of this finding.

“Not only do week seek better efficiency, but also lower costs too,” he added.
His co-authors on the paper include student Woo-Jun Yoon, who is conducting this work for his doctoral degree; Fernando Teixeira, associate professor of electrical and computer engineering; and Jiwen Liu, Thirumalai Durasisamy, Rao Revur, and Suvankar Sengupa -- all of MetaMateria Partners, LLC, formerly of Columbus, Ohio, which coated the silver nano-particles with polymer.

This work was funded by the Wright Center for Photovoltaics Innovation and Commercialization, and the Institute for Materials Research at Ohio State.

Contact: Paul R. Berger, (614) 247-6235; pberger@ieee.org

Pam Frost Gorder | Newswise Science News
Further information:
http://www.osu.edu

More articles from Power and Electrical Engineering:

nachricht Team develops fast, cheap method to make supercapacitor electrodes
18.07.2017 | University of Washington

nachricht Magic off the cuff
11.07.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

Leipzig HTP-Forum discusses "hydrothermal processes" as a key technology for a biobased economy

12.07.2017 | Event News

 
Latest News

Researchers create new technique for manipulating polarization of terahertz radiation

20.07.2017 | Information Technology

High-tech sensing illuminates concrete stress testing

20.07.2017 | Materials Sciences

First direct observation and measurement of ultra-fast moving vortices in superconductors

20.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>