Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > A bright future for optoelectronics: A diode made from a 2D material facilitates novel solar cells

A 2D Material opens up previously unimagined possibilities for solar cells, photodiodes and light-emitting diodes
A 2D Material opens up previously unimagined possibilities for solar cells, photodiodes and light-emitting diodes

Abstract:
A special type of diode made from a crystalline material whose layers are just three atoms thick has been successfully realized for the first time. The superior properties of such ultra-thin crystals open up previously unimagined possibilities for solar cells, photodiodes and light-emitting diodes. The paper, now published in Nature Nanotechnology, not only documents the actual functionality of a so-called p-n diode made of tungsten diselenide, it also demonstrates its usefulness for numerous applications. These findings, obtained through an Austrian Science Fund FWF project, thus constitute significant progress on the future path to 2D optoelectronics.

A bright future for optoelectronics: A diode made from a 2D material facilitates novel solar cells

Vienna, Austria | Posted on March 10th, 2014

Electronic devices require semiconductors. These are usually made from crystalline silicon. The state of the art here is the use of three-dimensional crystals. But these not only combine low flexibility with high weight - they are also expensive to manufacture. Alternative approaches - organic semiconductors and thin-film technologies - result, in turn, in materials with inferior quality and durability. Two-dimensional (2D) crystals - crystalline material layers with a thickness of just one or a few atoms - offer a better chance of success. They can be produced economically on a large scale and are flexible, yet still exhibit all the advantages of crystalline materials. Now a team from the Institute of Photonics at the Vienna University of Technology has succeeded in producing the first diode with a p-n junction from such 2D crystals - thus laying the foundation for radical changes in optoelectronics.

A GAP IN THE RESULT

The starting material used for this by the team working with Prof. Thomas Mueller was tungsten diselenide (WSe2). It has one major advantage over graphene, the most well-known 2D crystalline material at present, as Prof. Mueller explains: "Tungsten diselenide has a band gap - so electrons require a certain energy to cross over to the conduction band. Graphene can't easily provide this basic requirement for many electronic components." To ensure that WSe2 was actually present in the form of a 2D layer for the team's further work, it was mechanically "peeled" from three-dimensional crystals in such a way that layers having a thickness of just 0.7 nanometers were created. As Prof. Mueller explains: "We subsequently used complex procedures to check whether we had indeed succeeded in realizing 2D crystals, as only such thin layers exhibit the required properties." Spectroscopic analyses, optical contrast measurements and atomic force microscopy confirmed that the researchers had achieved the desired result. The monolayer WSe2 was then placed between two electrodes and the electrical characteristics were measured. This unambiguously confirmed its function as a p-n diode: it was possible to inject both positive (p, holes) and negative (n, electrons) charges, with current flow exclusively in one direction, as is usual in diodes.

THIN SUCCESS

"WSe2 in monolayer crystalline form is theoretically an ideal starting material for p-n diodes and optoelectronics - but no one had ever proven it before. We have now done just that. We measured an efficiency of 0.5 percent in converting light to electrical energy," says Prof. Mueller, explaining the first demonstration worldwide of the photovoltaic characteristics of a 2D crystalline material. The high transparency, at 95 percent, means it can even be used simultaneously as window glass and as a solar cell. However, it is also possible to stack several such ultra-thin layers one on top of another to increase the efficiency to as much as 10 percent - of course at the expense of transparency.

The material's functionality as a photodiode was also proven, achieving a sensitivity one order of magnitude higher than that of graphene. These properties are further enhanced by the ability to convert electrical energy to light.

Overall, the results of this FWF project offer impressive proof that WSe2 possesses superior optoelectronic properties that create new possibilities for solar cells, photodiodes and light-emitting diodes.

####

For more information, please click here

Contacts:
Scientific Contact:
Prof. Thomas Mueller
Vienna University of Technology
Photonics Institute
Gusshausstraße 27-29/E387
1040 Vienna, Austria
T +43 / 1 / 58801 - 38739
E

Austrian Science Fund FWF:
Mag. Stefan Bernhardt
Haus der Forschung
Sensengasse 1
1090 Vienna, Austria
T +43 / 1 / 505 67 40 - 8111
E
W http://www.fwf.ac.at

Copy Editing & Distribution:
PR&D - Public Relations for Research & Education
Mariannengasse 8
1090 Vienna, Austria
T +43 / 1 / 505 70 44
E
W http://www.prd.at

Copyright © Vienna University of Technology

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Original publication: A. Pospischil, M. M. Furchi, und T. Mueller, Solar-energy conversion and light emission in an atomic monolayer p-n diode, Nature Nanotechnology (2014):

Related News Press

News and information

Silicene Labs Announces the Launch of Patent-Pending, 2D Materials Composite Index™ : The Initial 2D Materials Composite Index™ for Q2 2014 Is: 857.3; Founders Include World-Renowned Physicist and Seasoned Business and IP Professionals July 24th, 2014

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

Deadline Announced for Registration in 7th Int'l Nanotechnology Festival in Iran July 23rd, 2014

A Crystal Wedding in the Nanocosmos July 23rd, 2014

Govt.-Legislation/Regulation/Funding/Policy

NNCO Announces an Interactive Webinar: Progress Review on the Coordinated Implementation of the National Nanotechnology Initiative 2011 Environmental, Health, and Safety Research Strategy July 23rd, 2014

Nano-sized Chip "Sniffs Out" Explosives Far Better than Trained Dogs: TAU researcher's groundbreaking sensor detects miniscule concentrations of hazardous materials in the air July 23rd, 2014

NIST shows ultrasonically propelled nanorods spin dizzyingly fast July 22nd, 2014

Penn Study: Understanding Graphene’s Electrical Properties on an Atomic Level July 22nd, 2014

Discoveries

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

UCF Nanotech Spinout Developing Revolutionary Battery Technology: Power the Next Generation of Electronics with Carbon July 23rd, 2014

A Crystal Wedding in the Nanocosmos July 23rd, 2014

Nano-sized Chip "Sniffs Out" Explosives Far Better than Trained Dogs: TAU researcher's groundbreaking sensor detects miniscule concentrations of hazardous materials in the air July 23rd, 2014

Announcements

Silicene Labs Announces the Launch of Patent-Pending, 2D Materials Composite Index™ : The Initial 2D Materials Composite Index™ for Q2 2014 Is: 857.3; Founders Include World-Renowned Physicist and Seasoned Business and IP Professionals July 24th, 2014

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

Deadline Announced for Registration in 7th Int'l Nanotechnology Festival in Iran July 23rd, 2014

A Crystal Wedding in the Nanocosmos July 23rd, 2014

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

A Crystal Wedding in the Nanocosmos July 23rd, 2014

Nano-sized Chip "Sniffs Out" Explosives Far Better than Trained Dogs: TAU researcher's groundbreaking sensor detects miniscule concentrations of hazardous materials in the air July 23rd, 2014

Penn Study: Understanding Graphene’s Electrical Properties on an Atomic Level July 22nd, 2014

Energy

Oregon chemists eye improved thin films with metal substitution: Solution-based inorganic process could drive more efficient electronics and solar devices July 21st, 2014

Steam from the sun: New spongelike structure converts solar energy into steam July 21st, 2014

3-D nanostructure could benefit nanoelectronics, gas storage: Rice U. researchers predict functional advantages of 3-D boron nitride July 15th, 2014

Nanotechnology that will impact the Security & Defense sectors to be discussed at NanoSD2014 conference July 8th, 2014

Photonics/Optics/Lasers

NUS scientists use low cost technique to improve properties and functions of nanomaterials: By 'drawing' micropatterns on nanomaterials using a focused laser beam, scientists could modify properties of nanomaterials for effective applications in photonic and optoelectric applicat July 22nd, 2014

Carbyne morphs when stretched: Rice University calculations show carbon-atom chain would go metal to semiconductor July 21st, 2014

Tiny laser sensor heightens bomb detection sensitivity July 19th, 2014

Future Electronics May Depend on Lasers, Not Quartz July 17th, 2014

Solar/Photovoltaic

Steam from the sun: New spongelike structure converts solar energy into steam July 21st, 2014

Making dreams come true: Making graphene from plastic? July 2nd, 2014

Shrinky Dinks close the gap for nanowires July 1st, 2014

New Study Raises Possibility of Production of P-Type Solar Cells July 1st, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE