Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. Solar Energy News .




SOLAR DAILY
Penn scientists demonstrate new method for harvesting energy from light
by Staff Writers
Philadelphia PA (SPX) Sep 17, 2013


Researchers fabricated nanostructures with various photoconduction properties.

Researchers from the University of Pennsylvania have demonstrated a new mechanism for extracting energy from light, a finding that could improve technologies for generating electricity from solar energy and lead to more efficient optoelectronic devices used in communications.

Dawn Bonnell, Penn's vice provost for research and Trustee Professor of Materials Science and Engineering in the School of Engineering and Applied Science, led the work, along with David Conklin, a doctoral student. The study involved a collaboration among additional Penn researchers, through the Nano/Bio Interface Center, as well as a partnership with the lab of Michael J. Therien of Duke University.

"We're excited to have found a process that is much more efficient than conventional photoconduction," Bonnell said. "Using such an approach could make solar energy harvesting and optoelectronic devices much better."

The study was published in the journal ACS Nano and will be discussed at a press conference at the American Chemical Society National Meeting and Exhibition in Indianapolis today at 10:30 a.m. (EDT).

The new work centers on plasmonic nanostructures, specifically, materials fabricated from gold particles and light-sensitive molecules of porphyin, of precise sizes and arranged in specific patterns. Plasmons, or a collective oscillation of electrons, can be excited in these systems by optical radiation and induce an electrical current that can move in a pattern determined by the size and layout of the gold particles, as well as the electrical properties of the surrounding environment.

Because these materials can enhance the scattering of light, they have the potential to be used to advantage in a range of technological applications, such as increasing absorption in solar cells.

In 2010, Bonnell and colleagues published a paper in ACS Nano reporting the fabrication of a plasmonic nanostructure, which induced and projected an electrical current across molecules. In some cases they designed the material, an array of gold nanoparticles, using a technique Bonnell's group invented, known as ferroelectric nanolithography.

The discovery was potentially powerful, but the scientists couldn't prove that the improved transduction of optical radiation to an electrical current was due to the "hot electrons" produced by the excited plasmons. Other possibilities included that the porphyin molecule itself was excited or that the electric field could focus the incoming light.

"We hypothesized that, when plasmons are excited to a high energy state, we should be able to harvest the electrons out of the material," Bonnell said. "If we could do that, we could use them for molecular electronics device applications, such as circuit components or solar energy extraction."

To examine the mechanism of the plasmon-induced current, the researchers systematically varied the different components of the plasmonic nanostructure, changing the size of the gold nanoparticles, the size of the porphyin molecules and the spacing of those components. They designed specific structures that ruled out the other possibilities so that the only contribution to enhanced photocurrent could be from the hot electrons harvested from the plasmons.

"In our measurements, compared to conventional photoexcitation, we saw increases of three to 10 times in the efficiency of our process," Bonnell said. "And we didn't even optimize the system. In principle you can envision huge increases in efficiency."

Devices incorporating this process of harvesting plasmon-induced hot electrons could be customized for different applications by changing the size and spacing of nanoparticles, which would alter the wavelength of light to which the plasmon responds.

"You could imagine having a paint on your laptop that acted like a solar cell to power it using only sunlight," Bonnell said. "These materials could also improve communications devices, becoming part of efficient molecular circuits."

The Penn team included Bonnell, Conklin, Sanjini Nanayakkara and Xi Chen from Engineering's Department of Materials Science and Engineering and Tae-Hong Park from the School of Arts and Sciences' Department of Chemistry. Other coauthors included Marie F. Lagadec from ETH Zurich and Therien and Joshua T. Stecher of Duke. The research was supported by the U.S. Department of Energy and the National Science Foundation.

.


Related Links
University of Pennsylvania
All About Solar Energy at SolarDaily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





SOLAR DAILY
Celestica's Solar Lab Receives Approval from TUV Rheinland PTL
Toronto, Canada (SPX) Sep 18, 2013
Celestica and TUV Rheinland PTL have announced that TUV Rheinland PTL has audited and approved Celestica's solar lab in Toronto, Ontario, to accept testing data generated by Celestica in Toronto. Celestica's solar lab is a state-of-the-art facility, with experience in product testing and analysis, and is capable of carrying out tests for a variety of PV standards, including UL-1703 / ULC-1 ... read more


SOLAR DAILY
Sharing the risks/costs of biomass crops

Indy 500 race cars showcase green fuels

Researchers Read the Coffee Grounds and Find a Promising Energy Resource For the Future

Professor and student develop device to detect biodiesel contamination

SOLAR DAILY
Robots take over

A swarm on every desktop: Robotics experts learn from public

European researchers envision wearable exoskeleton for factory workers

Ultra-fast trading robots can send markets out of control

SOLAR DAILY
Moventas significantly expands wind footprint

No evidence of residential property value impacts near US wind turbines

French court rejects planned wind farm near Mont Saint Michel

China to Remain Wind Power Market Leader in 2020

SOLAR DAILY
Bicycle built by Dutch students sets speed record of 83.13 mph

Swiss engineers create hybrid car engine said capable of 117 mpg

The new allure of electric cars: Blazing-fast speeds

France's Renault teams up with electric car pioneer

SOLAR DAILY
Ecuador's Correa calls for Chevron boycott

Study: Less methane leaks from fracking than EPA says

How the newest diesel engines emit very little greenhouse gas nitrous oxide

Probing methane's secrets: From diamonds to Neptune

SOLAR DAILY
Over 1,000 tons of Fukushima water dumped after typhoon

Japan nuclear-free as last reactor switched off

Queensland aims to resume uranium mining

Japan to be nuclear-free as last reactor switched off

SOLAR DAILY
Renewable Energy to Represent One-Fifth of the Global Installed Capacity by 2030

WELTEC BIOPOWER Develops Green Energy in France

AREVA wins a contract for a cogeneration power plant in France

Tool Created to Avert Future Energy Crisis

SOLAR DAILY
US slaps high dumping tariffs on Chinese wood products

Amazon deforestation due in part to soybean growing

An unprecedented threat to Peru's cloud forests

Climate Change May Speed Up Forests' Life Cycles




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement