Featured Research

from universities, journals, and other organizations

Catching some rays: Organic solar cells make a leap forward

Date:
June 14, 2012
Source:
DOE/Argonne National Laboratory
Summary:
Organic solar cells are becoming more efficient thanks to a new set of discoveries that alter their behaviors at the electronic level.

Drawn together by the force of nature, but pulled apart by the force of man -- it sounds like the setting for a love story, but it is also a basic description of how scientists have begun to make more efficient organic solar cells.

At the atomic level, organic solar cells function like the feuding families in Romeo and Juliet. There's a strong natural attraction between the positive and negative charges that a photon generates after it strikes the cell, but in order to capture the energy, these charges need to be kept separate.

When these charges are still bound together, they are known to scientists as an exciton. "The real question that this work tries to answer is how to design a material that will make splitting the exciton require less energy," said senior chemist Lin Chen of the U.S. Department of Energy's (DOE) Argonne National Laboratory.

Excitons can be thought of as a sort of "quasiparticle," Chen said, because they exhibit certain unique behaviors. When the two charged regions of the exciton -- the electron and a region known as a "hole" -- are close together, they are difficult to pry apart.

"The closer the hole and the electron regions are inside an exciton, the more likely they are to recombine without generating electricity," Chen said.

When energy is added to the system, however, the charges begin to separate, rendering the electrons and holes completely free and eventually allowing for the possibility of generating current and extracting electricity

"The closer the hole and the electron regions are inside an exciton, the more likely they are to recombine without generating electricity," Chen said. "But if they are already 'pre-separated,' or polarized, the more likely they are to escape from this potential trap and become effective charge carriers."

In the new experiment, Chen and her colleagues examined how four different molecules in the polymer layer in the middle of a solar cell generated different exciton dynamics. They discovered that more heavily polarized excitons yielded more efficient polymer-based solar cells.

"If the conventional exciton, right after it is generated, contains the hole and electron in almost the same location, these new materials are generating an exciton that is much more polarized at the beginning," Chen said. Currently, the collaborative team is exploring new materials for high-efficiency organic solar cells based on these findings.

Organic solar cells still have a ways to go to get close to the efficiency of their inorganic, silicon-based competitors, but they remain much more attractive from a cost perspective. Further research into the electronic dynamics of organic photovoltaics is essential to improving their efficiency and thus making solar power cost-competitive with conventional energy sources, Chen said.

The work has been recently published in the Journal of the American Chemical Society.


Story Source:

The above story is based on materials provided by DOE/Argonne National Laboratory. The original article was written by Jared Sagoff. Note: Materials may be edited for content and length.


Cite This Page:

DOE/Argonne National Laboratory. "Catching some rays: Organic solar cells make a leap forward." ScienceDaily. ScienceDaily, 14 June 2012. <www.sciencedaily.com/releases/2012/06/120614182755.htm>.
DOE/Argonne National Laboratory. (2012, June 14). Catching some rays: Organic solar cells make a leap forward. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2012/06/120614182755.htm
DOE/Argonne National Laboratory. "Catching some rays: Organic solar cells make a leap forward." ScienceDaily. www.sciencedaily.com/releases/2012/06/120614182755.htm (accessed October 21, 2014).

Share This



More Earth & Climate News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

Newsy (Oct. 20, 2014) The United Nations says water is a human right, but should it be free? Detroit has cut off water to residents who can't pay, and the U.N. isn't happy. Video provided by Newsy
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
White Rhino's Death In Kenya Means Just 6 Are Left

White Rhino's Death In Kenya Means Just 6 Are Left

Newsy (Oct. 20, 2014) Suni, a rare northern white rhino at Ol Pejeta Conservancy, died Friday. This, as many media have pointed out, leaves people fearing extinction. Video provided by Newsy
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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