Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. Solar Energy News .




SOLAR DAILY
New Material Promises Better Solar Cells
by Staff Writers
Vienna, Austria (SPX) Feb 14, 2013


Elias Assmann (left) and Karsten Held (right) demonstrate the idea behind the new solar cell: Light is absorbed by a layered structure, free charge carrieres are produced and electric current starts to flow.

Single atomic layers are combined to create novel materials with completely new properties. Layered oxide heterostructures are a new class of materials, which has attracted a great deal of attention among materials scientists in the last few years. A research team at the Vienna University of Technology, together with colleagues from the USA and Germany, has now shown that these heterostructures can be used to create a new kind of extremely efficient ultra-thin solar cells.

"Single atomic layers of different oxides are stacked, creating a material with electronic properties which are vastly different from the properties the individual oxides have on their own", says Professor Karsten Held from the Institute for Solid State Physics, Vienna University of Technology.

In order to design new materials with exactly the right physical properties, the structures were studied in large-scale computer simulations. As a result of this research, the scientists at TU Vienna discovered that the oxide heterostructures hold great potential for building solar cells.

Turning Light into Electricity
The basic idea behind solar cells is the photoelectric effect. Its simplest version was already explained by Albert Einstein in 1905: when a photon is absorbed, it can cause an electron to leave its place and electric current starts to flow.

When an electron is removed, a positively charged region stays behind - a so called "hole". Both the negatively charged electrons as well as the holes contribute to the electrical current.

"If these electrons and holes in the solar cell recombine instead of being transported away, nothing happens and the energy cannot be used", says Elias Assmann, who carried out a major part of the computer simulations at TU Vienna. "The crucial advantage of the new material is that on a microscopic scale, there is an electric field inside the material, which separates electrons and holes." This increases the efficiency of the solar cell.

Two Isolators Make a Metal
The oxides used to create the material are actually isolators. However, if two appropriate types of isolators are stacked, an astonishing effect can be observed: the surfaces of the material become metallic and conduct electrical current.

"For us, this is very important. This effect allows us to conveniently extract the charge carriers and create an electrical circuit", says Karsten Held. Conventional solar cells made of silicon require metal wires on their surface to collect the charge carriers - but these wires block part of the light from entering the solar cell.

Not all photons are converted into electrical current with the same efficiency. For different colors of light, different materials work best. "The oxide heterostructures can be tuned by choosing exactly the right chemical elements", says Professor Blaha (TU Vienna). In the computer simulations, oxides containing Lanthanum and Vanadium were studied, because that way the materials operate especially well with the natural light of the sun. "It is even possible to combine different kinds of materials, so that different colors of light can be absorbed in different layers of the solar cell at maximum efficiency", says Elias Assmann.

Putting Theory into Practice
The team from TU Vienna was assisted by Satoshi Okamoto (Oak Ridge National Laboratory, Tennessee, USA) and Professor Giorgio Sangiovanni, a former employee of TU Vienna, who is now working at Wurzburg University, Germany.

In Wurzburg, the new solar cells will now be build and tested. "The production of these solar cells made of oxide layers is more complicated than making standard silicon solar cells. But wherever extremely high efficiency or minimum thickness is required, the new structures should be able to replace silicon cells", Karsten Held believes.

Original Paper

.


Related Links
Vienna University of Technology
All About Solar Energy at SolarDaily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





SOLAR DAILY
Trina Solar Ranked No. 1 in Australia
Changzhou, China (SPX) Feb 14, 2013
Trina Solar has announced that it has achieved the No. 1 position in Australia's PV market. According to a new report from Solar Business Services ("Australian PV - Technology and Brands 2013"), Trina Solar was the most popular solar panel brand in Australia during 2012, accounting for 100MW of installations. The rise to the top position is attributed to the success of its high-performing ... read more


SOLAR DAILY
Newly discovered plant structure may lead to improved biofuel processing

Hydrothermal liquefaction - the most promising path to a sustainable bio-oil production

Scientists turn toxic by-product into biofuel booster

Reaping Profits from Landfill Biogas

SOLAR DAILY
Insect drives robot to track down smells

Foundation Helps Promote New Robotics Teams Worldwide

Engineers Building Hard-working Mining Robot

Robofish Grace glides with the greatest of ease

SOLAR DAILY
Gone with the wind: French scheme targets farting cows

Mainstream Renewable Power Starts Building Wind Farm in Chile

Sabotage may have felled U.K. wind turbine

Hgcapital And Blue Energy Agree UK Wind Farm Investment Deal

SOLAR DAILY
Nissan profit tumbles on China, Europe woes

Japan's Suzuki sees April-December net profit rise 19%

Japan's Mazda swings back to profit

China auto sales hit record in January: industry group

SOLAR DAILY
IEA to improve Chinese oil demand stats

Queensland approves shale development

Russia to tap global LNG market

Can Leak Detection End the Pipeline Impasse

SOLAR DAILY
Roof collapses at Chernobyl nuclear plant: Ukraine

Fukushima survivors to sue Japan government

Finland's TVO says reactor may be delayed until 2016

France debates nuke waste facility

SOLAR DAILY
Bulgarians protest high energy costs

Genscape Announces Strategic Partnership with Murex to Create Supply of QAP-A RINS

Diageo Transitions to 100 Percent Renewable Electricity at its North American HQ

China plans stricter fuel standards after smog

SOLAR DAILY
Lungs of the planet reveal their true sensitivity to global warming

Southwest regional warming likely cause of pinyon pine cone decline

Tree die-off triggered by hotter temperatures

Taiwan's 'King of the Trees' fights for the forests




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement