Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Why solar cells lose potency

20.06.2005


Commercial products such as laptop computer monitors and solar-powered calculators are constructed from a light-sensitive material with a peculiar problem: When exposed to intense light, it forms defects, reducing the efficiency of the solar cells by 10 to 15 percent.

Scientists have been pondering this flaw since the 1970s, because the material – hydrogenated amorphous silicon, or a-Si:H – has important applications for solar energy generation. A new study reported in the June 13 issue of the journal Applied Physics Letters, however, suggests that Ohio University scientists may have found the root of the problem.

When this photovoltaic material is exposed to intense light, hydrogen atoms move into new arrangements in which some silicon atoms become bonded to two silicon and two hydrogen atoms, creating a structure called silicon dihydride, or SiH2, said David Drabold, Presidential Research Scholar and professor of physics and astronomy at Ohio University, who co-authored the paper with graduate student Tesfaye Abtew and P. C. Taylor, Distinguished Professor of Physics at the University of Utah.



It’s a process analogous to what happens when light hits photographic film, Drabold explained. Light prompts small clusters of silver atoms to accumulate at the surface and form an image. In the case of the photovoltaic material, however, light makes hydrogen atoms move, which creates undesirable defects.

Drabold and Abtew came to the conclusion after running quantum mechanical computer simulations of how the atoms in the material respond to light. The work is based jointly on the simulations and on experimental findings by Taylor and his group.

"This isn’t a fatal effect, but it does reduce performance. It would be nice if the problem could be ameliorated some," said Drabold, who is funded by the National Science Foundation.

The scientists currently are devising further models to explain how hydrogen motion and creation of SiH2 wreak havoc on the solar cells, and are beginning to understand its pathways, he added.

Though a-SiH isn’t the only photovoltaic material of interest to the solar power industry, figuring out to address the flaw could lead to improvements in this important class of solar cells, Drabold said.

"If you can figure out what is going on, at least you have some reasonable guidance for how to solve it, such as adding some impurity to block it," he said.

Though popularly used in consumer products such as flat-screen computer monitor displays and calculators, a-Si:H materials also have potential for large-scale energy production. They are almost as efficient as conventional electric generation, especially in sunny areas, and they don’t generate greenhouse gases, he noted.

Andrea Gibson | EurekAlert!
Further information:
http://www.ohio.edu

More articles from Power and Electrical Engineering:

nachricht A big nano boost for solar cells
18.01.2017 | Kyoto University and Osaka Gas effort doubles current efficiencies

nachricht Multiregional brain on a chip
16.01.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>