Featured Research

from universities, journals, and other organizations

Cheap New Solar Cells Made Much More Efficient

Date:
March 24, 2008
Source:
Delft University of Technology
Summary:
A cheap alternative to silicon solar cells can be found in dye-sensitized solar cells. This type of cell imitates the natural conversion of sunlight into energy by, for instance, plants and light-sensitive bacteria. Researchers have now succeeded in substantially improving a process in this type of solar cell, which is similar to Graetzel cells.

A cheap alternative to silicon solar cells can be found in dye-sensitised solar cells. This type of cell imitates the natural conversion of sunlight into energy by, for instance, plants and light-sensitive bacteria. Annemarie Huijser has succeeded in substantially improving a process in this type of solar cell, which is similar to Grätzel cells.

The use of solar cells is increasing very slowly. One of the reasons is that the most commonly used type, made from silicon, is quite expensive to manufacture. That is why there has been a great deal of research into alternative solar cells over the past few years.

In searching for solutions, scientists are inspired by nature. Plants are able to transport absorbed solar energy over long distances, typically about 15-20 nanometres, to a location in which it is converted into chemical energy. This is because the chlorophyll molecules in their leaves are arranged in the best possible sequence. During her PhD,* Annemarie Huijser attempted a partial recreation in solar cells of this process as found in plants.

She focused on what are known as dye-sensitised solar cells. These comprise a semiconductor, such as titanium dioxide, covered with a layer of dye. The dye absorbs energy from sunlight, which creates what are known as excitons. These energy parcels then need to move towards to the semiconductor. Once there, they generate electric power.

Lego

Huijser: "You can compare dye molecules to Lego bricks. I vary the way the bricks are stacked and observe how this influences the exciton transport through the solar cells. Excitons need to move as freely as possible through the solar cells in order to generate electricity efficiently."

By studying the best sequence of dye molecules, Huijser succeeded in increasing the average distance which the excitons move in the solar cell by twenty times up to a distance of approximately 20 nanometres, comparable to systems found in nature. This substantially increases the efficiency of the cells.

In order to make this new type of solar cell commercially viable, Huijser estimates that the mobility of the excitons needs to increase further by a factor of three. She believes that this is certainly possible. 'Once that has been achieved, there is nothing to stop this type of solar cell being developed further.'

Grätzel cells

The solar cells used by Huijser are closely related to the more widely known Grätzel cells. In the case of Grätzel cells, however, the dye and semiconductor are very close to each other, they are almost blended. As a result, the excitons do not need to move that far. One disadvantage of this type of cell, however, is the complicated method of charge transport. For this reason, Huijser chose to adopt a different approach and use this simple dual-layer system of dye and semiconductor.

*Huijser will receive her PhD on this subject from TU Delft on Tuesday 25 March.

 

Story Source:

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


Cite This Page:

Delft University of Technology. "Cheap New Solar Cells Made Much More Efficient." ScienceDaily. ScienceDaily, 24 March 2008. <www.sciencedaily.com/releases/2008/03/080320095008.htm>.
Delft University of Technology. (2008, March 24). Cheap New Solar Cells Made Much More Efficient. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2008/03/080320095008.htm
Delft University of Technology. "Cheap New Solar Cells Made Much More Efficient." ScienceDaily. www.sciencedaily.com/releases/2008/03/080320095008.htm (accessed July 29, 2014).

Share This




More Matter & Energy News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Baluchistan Mining Eyes an Uncertain Future

Baluchistan Mining Eyes an Uncertain Future

AFP (July 29, 2014) — Coal mining is one of the major industries in Baluchistan but a lack of infrastructure and frequent accidents mean that the area has yet to hit its potential. Duration: 01:58 Video provided by AFP
Powered by NewsLook.com
Easier Nuclear Construction Promises Fall Short

Easier Nuclear Construction Promises Fall Short

AP (July 29, 2014) — The U.S. nuclear industry started building its first new plants using prefabricated Lego-like blocks meant to save time and prevent the cost overruns that crippled the sector decades ago. So far, it's not working. (July 29) Video provided by AP
Powered by NewsLook.com
Lithium Battery 'Holy Grail' Could Provide 4 Times The Power

Lithium Battery 'Holy Grail' Could Provide 4 Times The Power

Newsy (July 28, 2014) — Stanford University published its findings for a "pure" lithium ion battery that could have our everyday devices and electric cars running longer. 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

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