Featured Research

from universities, journals, and other organizations

Graphene: A material that multiplies the power of light

Date:
February 24, 2013
Source:
ICFO-The Institute of Photonic Sciences
Summary:
Researchers have demonstrated that graphene is able to convert a single photon that it absorbs into multiple electrons that could drive electric current -- a very promising discovery that makes graphene an important alternative material for light detection and harvesting technologies, now based on conventional semiconductors like silicon.

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.

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.

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 €1.000 million in graphene research.


Story Source:

The above story is based on materials provided by ICFO-The Institute of Photonic Sciences. Note: Materials may be edited for content and length.


Journal Reference:

  1. K. J. Tielrooij, J. C. W. Song, S. A. Jensen, A. Centeno, A. Pesquera, A. Zurutuza Elorza, M. Bonn, L. S. Levitov, F. H. L. Koppens. Photoexcitation cascade and multiple hot-carrier generation in graphene. Nature Physics, 2013; DOI: 10.1038/nphys2564

Cite This Page:

ICFO-The Institute of Photonic Sciences. "Graphene: A material that multiplies the power of light." ScienceDaily. ScienceDaily, 24 February 2013. <www.sciencedaily.com/releases/2013/02/130224142831.htm>.
ICFO-The Institute of Photonic Sciences. (2013, February 24). Graphene: A material that multiplies the power of light. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2013/02/130224142831.htm
ICFO-The Institute of Photonic Sciences. "Graphene: A material that multiplies the power of light." ScienceDaily. www.sciencedaily.com/releases/2013/02/130224142831.htm (accessed October 22, 2014).

Share This



More Matter & Energy News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Reuters - Innovations Video Online (Oct. 22, 2014) — Inspired by the way a chameleon changes its colour to disguise itself; scientists in Poland want to replace traditional camouflage paint with thousands of electrochromic plates that will continuously change colour to blend with its surroundings. The first PL-01 concept tank prototype will be tested within a few years, with scientists predicting that a similar technology could even be woven into the fabric of a soldiers' clothing making them virtually invisible to the naked eye. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Jet Sales Lift Boeing Profit 18 Pct.

Jet Sales Lift Boeing Profit 18 Pct.

Reuters - Business Video Online (Oct. 22, 2014) — Strong jet demand has pushed Boeing to raise its profit forecast for the third time, but analysts were disappointed by its small cash flow. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Internet of Things Aims to Smarten Your Life

Internet of Things Aims to Smarten Your Life

AP (Oct. 22, 2014) — As more and more Bluetooth-enabled devices are reaching consumers, developers are busy connecting them together as part of the Internet of Things. (Oct. 22) Video provided by AP
Powered by NewsLook.com
What Is Magic Leap, And Why Is It Worth $500M?

What Is Magic Leap, And Why Is It Worth $500M?

Newsy (Oct. 22, 2014) — Magic Leap isn't publicizing much more than a description of its product, but it’s been enough for Google and others to invest more than $500M. Video provided by Newsy
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:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

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