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 IHP presents the fastest silicon-based transistor in the world
05.12.2016 | IHP - Leibniz-Institut für innovative Mikroelektronik

nachricht High-precision magnetic field sensing
05.12.2016 | ETH Zurich

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: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

InLight study: insights into chemical processes using light

05.12.2016 | Materials Sciences

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>