Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



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

INRS and ELI deepen strategic partnership to train the next generation in laser science:PhD students will benefit from international mobility and privileged access to cutting-edge infrastructure June 6th, 2025

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025

A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025

Govt.-Legislation/Regulation/Funding/Policy

INRS and ELI deepen strategic partnership to train the next generation in laser science:PhD students will benefit from international mobility and privileged access to cutting-edge infrastructure June 6th, 2025

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

Institute for Nanoscience hosts annual proposal planning meeting May 16th, 2025

Rice researchers harness gravity to create low-cost device for rapid cell analysis February 28th, 2025

Discoveries

Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025

Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025

Announcements

INRS and ELI deepen strategic partnership to train the next generation in laser science:PhD students will benefit from international mobility and privileged access to cutting-edge infrastructure June 6th, 2025

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025

A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters

Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025

A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025

Energy

Portable Raman analyzer detects hydrogen leaks from a distance: Device senses tiny concentration changes of hydrogen in ambient air, offering a dependable way to detect and locate leaks in pipelines and industrial systems April 25th, 2025

KAIST researchers introduce new and improved, next-generation perovskite solar cell​ November 8th, 2024

Unveiling the power of hot carriers in plasmonic nanostructures August 16th, 2024

Groundbreaking precision in single-molecule optoelectronics August 16th, 2024

Photonics/Optics/Lasers

INRS and ELI deepen strategic partnership to train the next generation in laser science:PhD students will benefit from international mobility and privileged access to cutting-edge infrastructure June 6th, 2025

Institute for Nanoscience hosts annual proposal planning meeting May 16th, 2025

Following the folds – with quantum technology: The connection between a crumpled sheet of paper and quantum technology: A research team at the EPFL in Lausanne (Switzerland) and the University of Konstanz (Germany) uses topology in microwave photonics to make improved systems of May 16th, 2025

Programmable electron-induced color router array May 14th, 2025

Solar/Photovoltaic

KAIST researchers introduce new and improved, next-generation perovskite solar cell​ November 8th, 2024

Groundbreaking precision in single-molecule optoelectronics August 16th, 2024

Development of zinc oxide nanopagoda array photoelectrode: photoelectrochemical water-splitting hydrogen production January 12th, 2024

Shedding light on unique conduction mechanisms in a new type of perovskite oxide November 17th, 2023

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




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project