Featured Research

from universities, journals, and other organizations

Scientists demonstrate new method for harvesting energy from light

Date:
September 9, 2013
Source:
University of Pennsylvania
Summary:
Researchers 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.

Researchers fabricated nanostructures with various photoconduction properties.
Credit: Image courtesy of University of Pennsylvania

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 was discussed at a press conference at the American Chemical Society National Meeting and Exhibition in Indianapolis today.

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.


Story Source:

The above story is based on materials provided by University of Pennsylvania. Note: Materials may be edited for content and length.


Journal Reference:

  1. David Conklin, Sanjini Nanayakkara, Tae-Hong Park, Marie F. Lagadec, Joshua T. Stecher, Xi Chen, Michael J. Therien, Dawn A. Bonnell. Exploiting Plasmon-Induced Hot Electrons in Molecular Electronic Devices. ACS Nano, 2013; 7 (5): 4479 DOI: 10.1021/nn401071d

Cite This Page:

University of Pennsylvania. "Scientists demonstrate new method for harvesting energy from light." ScienceDaily. ScienceDaily, 9 September 2013. <www.sciencedaily.com/releases/2013/09/130909131230.htm>.
University of Pennsylvania. (2013, September 9). Scientists demonstrate new method for harvesting energy from light. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2013/09/130909131230.htm
University of Pennsylvania. "Scientists demonstrate new method for harvesting energy from light." ScienceDaily. www.sciencedaily.com/releases/2013/09/130909131230.htm (accessed April 23, 2014).

Share This



More Matter & Energy News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Is North Korea Planning Nuclear Test #4?

Is North Korea Planning Nuclear Test #4?

Newsy (Apr. 22, 2014) South Korean officials say North Korea is preparing to conduct another nuclear test, but is Pyongyang just bluffing this time? Video provided by Newsy
Powered by NewsLook.com
China Falls for 4x4s at Beijing Auto Show

China Falls for 4x4s at Beijing Auto Show

AFP (Apr. 22, 2014) The urban 4x4 is the latest must-have for Chinese drivers, whose conversion to the cult of the SUV is the talking point of this year's Beijing auto show. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Lytro Introduces 'Illum,' A Professional Light-Field Camera

Lytro Introduces 'Illum,' A Professional Light-Field Camera

Newsy (Apr. 22, 2014) The light-field photography engineers at Lytro unveiled their next innovation: a professional DSLR-like camera called "Illum." Video provided by Newsy
Powered by NewsLook.com
3 Reasons Why Harley Davidson Is Selling Tons of Epic Hogs

3 Reasons Why Harley Davidson Is Selling Tons of Epic Hogs

TheStreet (Apr. 22, 2014) Sales of motorcycles have continued to ride back from the depths of hell known as the Great Recession. Excluding scooters, sales of motorcycles increased 3% in 2013. In units, however, at 465,000 sold last year, the total remained about 50% below the peak hit in 2007. Industry leader Harley Davidson’s shareholders have benefited both by the industry recovery and positive headlines emanating from the company. Belus Capital Advisors CEO Brian Sozzi takes you beyond the headlines of the motorcycle maker. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins