. Medical and Hospital News .




SOLAR DAILY
Graphene: A material that multiplies the power of light
by Staff Writers
Madrid, Spain (SPX) Feb 26, 2013


File image.

Bottles, packaging, furniture, car parts... all made of plastic. Today we find it difficult to imagine our lives without this key material that revolutionized technology over the last century.

There is wide-spread optimism in the scientific community that graphene will provide similar paradigm shifting advances in the decades to come. Mobile phones that fold, transparent and flexible solar panels, extra thin computers... the list of potential applications is endless. Scientists, industries and the European Commission are so convinced of the potential of graphene to revolutionize the world economy that they promise an injection of euro 1.000 million in graphene research.

The most recent discovery published in Nature Physics and made by researchers at the Institute of Photonic Science (ICFO), in collaboration with Massachusetts Institute of Technology, USA, Max Planck Institute for Polymer Research, Germany, and Graphenea S.L. Donostia-San Sebastian, Spain, demonstrate that graphene is able to convert a single photon that it absorbs into multiple electrons that could drive electric current (excited electrons) - a very promising discovery that makes graphene an important alternative material for light detection and harvesting technologies, now based on conventional semiconductors like silicon.

"In most materials, one absorbed photon generates one electron, but in the case of graphene, we have seen that one absorbed photon is able to produce many excited electrons, and therefore generate larger electrical signals" explains Frank Koppens, group leader at ICFO.

This feature makes graphene an ideal building block for any device that relies on converting light into electricity. In particular, it enables efficient light detectors and potentially also solar cells that can harvest light energy from the full solar spectrum with lower loss.

The experiment consisted in sending a known number of photons with different energies (different colors) onto a monolayer of graphene. "We have seen that high energy photons (e.g. violet) are converted into a larger number of excited electrons than low energy photons (e.g. infrared).

The observed relation between the photon energy and the number of generated excited electrons shows that graphene converts light into electricity with very high efficiency. Even though it was already speculated that graphene holds potential for light-to-electricity conversion, it now turns out that it is even more suitable than expected!" explains Tielrooij, researcher at ICFO.

Although there are some issues for direct applications, such as graphene's low absorption, graphene holds the potential to cause radical changes in many technologies that are currently based on conventional semiconductors.

"It was known that graphene is able to absorb a very large spectrum of light colors. However now we know that once the material has absorbed light, the energy conversion efficiency is very high.

"Our next challenge will be to find ways of extracting the electrical current and enhance the absorption of graphene. Then we will be able to design graphene devices that detect light more efficiently and could potentially even lead to more efficient solar cells." concludes Koppens.

"Photoexcitation cascade and multiple hot-carrier generation in graphene". K.J. Tielrooij, J.C.W. Song, S.A. Jensen, A. Centeno, A. Pesquera, A. Zurutuza Elorza, M. Bonn, L.S. Levitov and F.H.L. Koppens.
.


Related Links
ICFO-The Institute of Photonic Sciences
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 Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Get Our Free Newsletters
Space - Defense - Environment - Energy - Solar - Nuclear

...





SOLAR DAILY
Forget about leprechauns, engineers are catching rainbows
Buffalo NY (SPX) Feb 26, 2013
University at Buffalo engineers have created a more efficient way to catch rainbows, an advancement in photonics that could lead to technological breakthroughs in solar energy, stealth technology and other areas of research. Qiaoqiang Gan, PhD, an assistant professor of electrical engineering at UB, and a team of graduate students described their work in a paper called "Rainbow Trapping in ... read more


SOLAR DAILY
Rio meet focuses on using science to root out poverty

British PM sparks concern with aid budget proposals

Swiss Re posts 61% profit rise in 2012

Four guilty of manslaughter in Italy quake trial

SOLAR DAILY
Telit Offers COMBO 2G Chip For Multi Satellite Positioning Receiver

Boeing Awarded USAF Contract to Continue GPS Modernization

A system that improves the precision of GPS in cities by 90 percent

System improves GPS in city locations

SOLAR DAILY
Stay cool and live longer?

Zuckerberg, Brin join forces to extend life

Thick hair mutation emerged 30,000 years ago in humans

Tiny mutation had big evolutionary impact

SOLAR DAILY
'Activating' RNA takes DNA on a loop through time and space

Evolutionary biologists urged to adapt their research methods

'Snooze button' on biological clocks improves cell adaptability

Mutant champions save imperiled species from extinction

SOLAR DAILY
China reports year's second fatal case of bird flu

Text messages help cholera fight in Mozambique

Humans and chimps share genetic strategy in battle against pathogens

Cold resistance runs in genes

SOLAR DAILY
China party mouthpiece laments spoiled generation

Chinese villagers told to flatten tombs: reports

Tibetan teens in rare double immolation: reports

US slams 'horrific' toll of Tibet self-immolations

SOLAR DAILY
Ukraine to join NATO anti-piracy mission

16 gunmen killed in Thai military base attack: army

Japan police arrest mobster in Fukushima clean-up

Mexico scrambles to stem violence near capital

SOLAR DAILY
Japan passes $142 billion stimulus budget

US science policy should focus on outcomes not efficiencies

China manufacturing growth falls in February

China ratings firm warns of global 'currency crisis'




The content herein, unless otherwise known to be public domain, are Copyright 1995-2012 - 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