Featured Research

from universities, journals, and other organizations

New connection between stacked solar cells can handle energy of 70,000 suns

Date:
September 6, 2013
Source:
North Carolina State University
Summary:
Researchers have come up with a new technique for improving the connections between stacked solar cells, which should improve the overall efficiency of solar energy devices and reduce the cost of solar energy production. The new connections can allow these cells to operate at solar concentrations of 70,000 suns' worth of energy without losing much voltage as 'wasted energy' or heat.

The discovery means solar cell manufacturers can create stacked solar cells that can handle high-intensity solar energies without losing voltage at the connecting junctions, potentially improving conversion efficiency.
Credit: NC State University

North Carolina State University researchers have come up with a new technique for improving the connections between stacked solar cells, which should improve the overall efficiency of solar energy devices and reduce the cost of solar energy production. The new connections can allow these cells to operate at solar concentrations of 70,000 suns' worth of energy without losing much voltage as "wasted energy" or heat.

Stacked solar cells consist of several solar cells that are stacked on top of one another. Stacked cells are currently the most efficient cells on the market, converting up to 45 percent of the solar energy they absorb into electricity.

But to be effective, solar cell designers need to ensure the connecting junctions between these stacked cells do not absorb any of the solar energy and do not siphon off the voltage the cells produce -- effectively wasting that energy as heat.

"We have discovered that by inserting a very thin film of gallium arsenide into the connecting junction of stacked cells we can virtually eliminate voltage loss without blocking any of the solar energy," says Dr. Salah Bedair, a professor of electrical engineering at NC State and senior author of a paper describing the work.

This work is important because photovoltaic energy companies are interested in using lenses to concentrate solar energy, from one sun (no lens) to 4,000 suns or more. But if the solar energy is significantly intensified -- to 700 suns or more -- the connecting junctions used in existing stacked cells begin losing voltage. And the more intense the solar energy, the more voltage those junctions lose -- thereby reducing the conversion efficiency.

"Now we have created a connecting junction that loses almost no voltage, even when the stacked solar cell is exposed to 70,000 suns of solar energy," Bedair says. "And that is more than sufficient for practical purposes, since concentrating lenses are unlikely to create more than 4,000 or 5,000 suns worth of energy. This discovery means that solar cell manufacturers can now create stacked cells that can handle these high-intensity solar energies without losing voltage at the connecting junctions, thus potentially improving conversion efficiency.

"This should reduce overall costs for the energy industry because, rather than creating large, expensive solar cells, you can use much smaller cells that produce just as much electricity by absorbing intensified solar energy from concentrating lenses. And concentrating lenses are relatively inexpensive," Bedair says.


Story Source:

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


Journal Reference:

  1. Joshua P. Samberg, C. Zachary Carlin, Geoff K. Bradshaw, Peter C. Colter, Jeffrey L. Harmon, J. B. Allen, John R. Hauser, S. M. Bedair. Effect of GaAs interfacial layer on the performance of high bandgap tunnel junctions for multijunction solar cells. Applied Physics Letters, 2013; 103 (10): 103503 DOI: 10.1063/1.4819917

Cite This Page:

North Carolina State University. "New connection between stacked solar cells can handle energy of 70,000 suns." ScienceDaily. ScienceDaily, 6 September 2013. <www.sciencedaily.com/releases/2013/09/130906102651.htm>.
North Carolina State University. (2013, September 6). New connection between stacked solar cells can handle energy of 70,000 suns. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2013/09/130906102651.htm
North Carolina State University. "New connection between stacked solar cells can handle energy of 70,000 suns." ScienceDaily. www.sciencedaily.com/releases/2013/09/130906102651.htm (accessed September 17, 2014).

Share This



More Earth & Climate News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Researchers Explore Shipwrecks Off Calif. Coast

Researchers Explore Shipwrecks Off Calif. Coast

AP (Sep. 16, 2014) Federal researchers are exploring more than a dozen underwater sites where they believe ships sank in the treacherous waters west of San Francisco in the decades following the Gold Rush. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Isolated N. Korea Asks For International Help With Volcano

Isolated N. Korea Asks For International Help With Volcano

Newsy (Sep. 16, 2014) Mount Paektu volcano in North Korea is showing signs of life and there's not much known about it. 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:
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