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 Energy-efficient spin current can be controlled by magnetic field and temperature
17.08.2018 | Johannes Gutenberg-Universität Mainz

nachricht Scientists create biodegradable, paper-based biobatteries
08.08.2018 | Binghamton University

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: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Quantum material is promising 'ion conductor' for research, new technologies

17.08.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>