Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Light-emitting triangles may have applications in optical technology

Triangular single layers of tungsten disulfide have been synthesized by Penn State researchers. The edges of the triangles exhibit extraordinary photoluminescence, while the interior area does not. The photoluminescent signal disappears as the number of layers increases. These triangular structures may have potential applications in optical technology; for example, for use in light detectors and lasers.

Credit: Terrones lab, Penn State Universtiy
Triangular single layers of tungsten disulfide have been synthesized by Penn State researchers. The edges of the triangles exhibit extraordinary photoluminescence, while the interior area does not. The photoluminescent signal disappears as the number of layers increases. These triangular structures may have potential applications in optical technology; for example, for use in light detectors and lasers.

Credit: Terrones lab, Penn State Universtiy

Abstract:
For the first time, scientists have created single layers of a naturally occurring rare mineral called tungstenite, or WS2. The resulting sheet of stacked sulfur and tungsten atoms forms a honeycomb pattern of triangles that have been shown to have unusual light-emitting, or photoluminescent, properties. According to team leader Mauricio Terrones, a professor of physics and of materials science and engineering at Penn State, the triangular structures have potential applications in optical technology; for example, for use in light detectors and lasers. The results of the research will be published in a print edition of the journal NANO Letters.

Light-emitting triangles may have applications in optical technology

University Park, PA | Posted on February 5th, 2013

Terrones explained that creating monolayers -- single, one-atom-thick layers -- is of special interest to scientists because the chemical properties of minerals and other substances are known to change depending on their atomic thickness, opening the door to potentially useful applications of multi-layered materials of various thicknesses. In previous research, scientists had accomplished the feat of making a monolayer of graphene -- a substance similar to the graphite found in pencil leads. "The technique these researchers used was tedious, but it worked," Terrones said. "They basically removed, or exfoliated, the graphene, layer by layer, with Scotch tape, until they got down to a single atom of thickness."

Now, for the first time, Terrones and his team have used a controlled thermal reduction-sulfurization method -- or chemical vapor deposition -- to accomplish the same feat with a rare mineral called tungstenite. The scientists began by depositing tiny crystals of tungsten oxide, which are less than one nanometer in height, and they then passed the crystals through sulfur vapor at 850 degrees Celsius. This process led to individual layers -- or sheets -- composed of one atom in thickness. The resulting structure -- called tungsten disulfide -- is a honeycomb pattern of triangles consisting of tungsten atoms bonded with sulfur atoms.

"One of the most exciting properties of the tungsten disulfide monolayer is its photoluminescence," Terrones said. Terrones explained that photoluminescence occurs when a substance absorbs light at one wavelength and re-emits that light at a different wavelength. The property of photoluminescence also occurs in certain bioluminescenent animals such as angler fish and fireflies. "One interesting discovery from our work is the fact that we see the strongest photoluminescence at the edges of the triangles, right where the chemistry of the atoms changes, with much less photoluminescence occurring in the center of the triangles," Terrones said. "We also have found that these new monolayers luminesce at room temperature. So no special temperature requirements are needed for the material to exhibit this property."

Co-author Vincent H. Crespi, Distinguished Professor of Physics, Chemistry, and Materials Science and Engineering at Penn State, added, "The images of the photoluminescence are beautiful; the triangles light up all around their edges like little holiday ornaments -- holiday ornaments with potentially transformative, long-term applications in nano-optics."

The research has many potential applications in the fields of optical light detection, the production of light-emitting diodes, and even laser technology. The researchers also plan to try the chemical-vapor-deposition technology to grow innovative monolayers using other layered materials with potentially useful applications.

In addition to Terrones and Crespi, other researchers who contributed to this study include Humberto R. Gutiérrez, an assistant professor at the University of Louisville; Nestor Perea-López and Ana Laura Elías, research associates at Penn State; Ayse Berkdemir and Ruitao Lv, posdoctoral fellows at Penn State; Bei Wang and Yuanxi Wang, graduate students at Penn State; and Florentino López-Urías and Humberto Terrones, visiting professors at Penn State.

Support for this research comes primarily from the U.S. Army Research Office and, in part, from the Penn State Center for Nanoscale Science.

[ Katrina Voss ]

GRANT NUMBERS: U.S. Army Research Office (MURI grant W911NF-11-1-0362), Penn State Center for Nanoscale Science (DMR-0820404)

####

For more information, please click here

Contacts:
Barbara Kennedy

814-863-4682

Mauricio Terrones:
814-865-0343


Vincent H. Crespi
814-863-0163

Copyright © Penn State

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 News Press

News and information

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

Scientists discover new 'boat' form of promising semiconductor: GeSe Uncommon form attenuates semiconductor's band gap size March 23rd, 2017

Chemistry

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Researchers develop groundbreaking process for creating ultra-selective separation membranes: Discovery could greatly improve energy-efficiency of separation and purification processes in the chemical and petrochemical industries March 15th, 2017

Optical fingerprint can reveal pollutants in the air: Researchers at Chalmers University of Technology have proposed a new, sophisticated method of detecting molecules with sensors based on ultra-thin nanomaterials March 15th, 2017

Display technology/LEDs/SS Lighting/OLEDs

UC researchers use gold coating to control luminescence of nanowires: University of Cincinnati physicists manipulate nanowire semiconductors in pursuit of making electronics smaller, faster and cheaper March 17th, 2017

Perovskite edges can be tuned for optoelectronic performance: Layered 2D material improves efficiency for solar cells and LEDs March 10th, 2017

Govt.-Legislation/Regulation/Funding/Policy

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Nanobiotix: The Independent Data Monitoring Committee Recommends the Continuation of the Ongoing Phase II/III Trial of NBTXR3 in Soft Tissue Sarcoma March 23rd, 2017

Rice U. refines filters for greener natural gas: New study defines best materials for carbon capture, methane selectivity March 23rd, 2017

Discoveries

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

Announcements

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

Tools

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Caught on camera -- chemical reactions 'filmed' at the single-molecule level March 22nd, 2017

CRMGroup in Belgium uses a Deben three point bending stage in the development of new steel & coated steel products for automotive and other industrial applications March 21st, 2017

Next-gen steel under the microscope March 18th, 2017

Military

Graphene sheets capture cells efficiently: New method could enable pinpoint diagnostics on individual blood cells March 3rd, 2017

Bioinspired process makes materials light, robust, programmable at nano- to macro-scale: Ultralight web of silk nano fibers withstands load 4,000 times its weight February 28th, 2017

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

Engineers shrink microscope to dime-sized device February 17th, 2017

Photonics/Optics/Lasers

Electro-optical switch transmits data at record-low temperatures: Operating at temperatures near absolute zero, switch could enable significantly faster data processing with lower power consumption March 20th, 2017

AIM Photonics Welcomes Coventor as Newest Member: US-Backed Initiative Taps Process Modeling Specialist to Enable Manufacturing of High-Yield, High-Performance Integrated Photonic Designs March 16th, 2017

Optical fingerprint can reveal pollutants in the air: Researchers at Chalmers University of Technology have proposed a new, sophisticated method of detecting molecules with sensors based on ultra-thin nanomaterials March 15th, 2017

MIPT physicists predict the existence of unusual optical composites March 10th, 2017

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