Featured Research

from universities, journals, and other organizations

New efficiency record for photovoltaic cells, thanks to heterojunction

Date:
September 27, 2012
Source:
Ecole Polytechnique Fédérale de Lausanne
Summary:
Scientists have developed photovoltaic cells with an energy conversion efficiency of 21.4 percent, the highest obtained for the type of substrate they used. This breakthrough will contribute to lowering the cost of solar-cell-based installations.

In the medium term, an investment of only $2500 in photovoltaic cells would suffice to provide more than enough electricity for the consumption of a four people household. This promising scenario has been made possible by the innovations accomplished by EPFL's Institute of Microengineering in Neuchatel. The team of prof. Christophe Ballif, director of the Photovoltaics Laboratory (PVlab), presented their work at the European Photovoltaic Solar Energy Conference and Exhibition that just took place in Frankfurt.

The PVlab specializes in thin film solar cells and has been interested for several years in "hybrid" technologies, better known as heterojunction technologies, designed to enhance solar captors' performance. "We apply an infinitesimal layer -- one hundredth of a micron -- of amorphous silicon on both sides of a crystalline silicon wafer," explains Christophe Ballif. This "sandwich" conception contributes to increase the sensors' effectiveness.

For this assembly to be efficient, the interface between the two types of silicon requires to be optimized. Antoine Descoeudres managed to achieve this feat together with Stephaan DeWolf and their colleagues. They chose the commonest -- and therefore cheapest -- crystalline cell (called "p-doped silicon"), took care of its preparation and improved the process of application of amorphous silicon. They obtained a 21.4% conversion efficiency, which had never been achieved before with such type of substrates: nowadays, the best quality monocrystalline cells only attain an energy conversion efficiency of 18-19% at best. In addition, the measured open-circuit voltage was 726 mV, which constitutes a first-time accomplishment as well. Last but not least, they broke the 22% efficiency barrier on a less common substrate.

These results, validated by the Fraunhofer Institute for Solar Energy Systems (ISE) in Germany, will soon be published by the IEEE Journal of photovoltaics.

To bring these innovations to a stage of industrialization may only take a few years. This research was partly financed as a commission for Roth & Rau Switzerland, whose parent company, Meyer Burger, has already started the commercialization of machines built for assembling this type of heterojunction sensors. "Within three to five years, we expect to reach a production cost of $100 per square meter of sensors, estimates Stefaan DeWolf. In Switzerland, with the conversion efficiency achieved, such a surface will be able to produce between 200 and 300 kWh of electricity per year. "


Story Source:

The above story is based on materials provided by Ecole Polytechnique Fédérale de Lausanne. Note: Materials may be edited for content and length.


Cite This Page:

Ecole Polytechnique Fédérale de Lausanne. "New efficiency record for photovoltaic cells, thanks to heterojunction." ScienceDaily. ScienceDaily, 27 September 2012. <www.sciencedaily.com/releases/2012/09/120927130221.htm>.
Ecole Polytechnique Fédérale de Lausanne. (2012, September 27). New efficiency record for photovoltaic cells, thanks to heterojunction. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2012/09/120927130221.htm
Ecole Polytechnique Fédérale de Lausanne. "New efficiency record for photovoltaic cells, thanks to heterojunction." ScienceDaily. www.sciencedaily.com/releases/2012/09/120927130221.htm (accessed July 28, 2014).

Share This




More Earth & Climate News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) — The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
The Carbon Trap: US Exports Global Warming

The Carbon Trap: US Exports Global Warming

AP (July 28, 2014) — AP Investigation: As the Obama administration weans the country off dirty fuels, energy companies are ramping-up overseas coal exports at a heavy price. (July 28) Video provided by AP
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) — A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com
Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) — A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. 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