Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Researchers set new record for brightness of quantum dots

Abstract:
By placing quantum dots on a specially designed photonic crystal, researchers at the University of Illinois have demonstrated enhanced fluorescence intensity by a factor of up to 108. Potential applications include high-brightness light-emitting diodes, optical switches and personalized, high-sensitivity biosensors.

Researchers set new record for brightness of quantum dots

Urbana-Champaign, IL | Posted on September 25th, 2007

"We are using photonic crystals in a new way," said Brian Cunningham, a professor of electrical and computer engineering and corresponding author of a paper published in the August issue of the journal Nature Nanotechnology. "We tune them to the specific wavelength of a laser used to stimulate the quantum dots, which couples the energy more efficiently and increases the brightness."

A quantum dot is a tiny piece of semiconductor material 2 to 10 nanometers in diameter (a nanometer is 1 billionth of a meter). When illuminated with invisible ultraviolet light, a quantum dot will fluoresce with visible light.

To enhance the fluorescence, Cunningham and colleagues at the U. of I. begin by creating plastic sheets of photonic crystal using a technique called replica molding. Then they fasten commercially available quantum dots to the surface of the plastic.

"We designed the photonic crystal to efficiently capture the light from an ultraviolet laser and to concentrate its intensity right within the surface where the quantum dots are located," said Cunningham, who also is affiliated with the university's Beckman Institute, the Micro and Nanotechnology Laboratory, and the Institute for Genomic Biology. "Enhanced absorption by the quantum dots is the first improvement we made."

Enhanced, directed emission from the quantum dots is the second improvement.

Quantum dots normally give off light in all directions. However, because the researchers' quantum dots are sitting on a photonic crystal, the energy can be channeled in a preferred direction - toward a detector, for example.

While the researchers report an enhancement of fluorescence intensity by a factor of up to 108 compared with quantum dots on an unpatterned surface, more recent (unpublished) work has exceeded a factor of 550.

"The enhanced brightness makes it feasible to use photonic crystals and quantum dots in biosensing applications from detecting DNA and other biomolecules, to detecting cancer cells, spores and viruses," Cunningham said. "More exotic applications, such as personalized medicine based on an individual's genetic profile, may also be possible."

Funding was provided by the National Science Foundation and SRU Biosystems. Part of the work was carried out in the university's Center for Microanalysis of Materials, which is partially supported by the U.S. Department of Energy.

####

For more information, please click here

Contacts:
James E. Kloeppel, Physical Sciences Editor

217-244-1073

Copyright © University of Illinois at Urbana-Champaign

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

Display technology/LEDs/SS Lighting/OLEDs

'Greener,' low-cost transistor heralds advance in flexible electronics September 24th, 2014

Nanotechnology leads to better, cheaper LEDs for phones and lighting September 24th, 2014

Southampton scientists grow a new challenger to graphene September 23rd, 2014

New research points to graphene as a flexible, low-cost touchscreen solution September 19th, 2014

Sensors

New Absorber Will Lead to Better Biosensor: Biosensors are more sensitive and able to detect smaller changes in the environment October 1st, 2014

Graphene and Amaranthus Superparamagnets: Breakthrough nanoparticles discovery of Indian researcher September 23rd, 2014

IEEE International Electron Devices Meeting To Celebrate 60th Anniversary as The Leading Technical Conference for Advanced Semiconductor Devices September 18th, 2014

Biosensors Get a Boost from Graphene Partnership: $5 Million Investment Supports Dozens of Jobs and Development of 300mm Fabrication Process and Wafer Transfer Facility September 18th, 2014

Discoveries

Nanoparticles Accumulate Quickly in Wetland Sediment: Aquatic food chains might be harmed by molecules "piggybacking" on carbon nanoparticles October 1st, 2014

'Stealth' nanoparticles could improve cancer vaccines October 1st, 2014

Stressed Out: Research Sheds New Light on Why Rechargeable Batteries Fail October 1st, 2014

New Absorber Will Lead to Better Biosensor: Biosensors are more sensitive and able to detect smaller changes in the environment October 1st, 2014

Quantum Dots/Rods

University of Electro-Communications research: High density quantum dots for powerful solar cells September 25th, 2014

Nano-pea pod model widens electronics applications: A new theoretical model explains how a nanostructure, such as the nano-pea pod, can exhibit localised electrons September 4th, 2014

Interaction between Drug, DNA for Designing Anticancer Drugs Studied in Iran August 17th, 2014

NANOPARTICLES INDIA August 8th, 2014

Photonics/Optics/Lasers

New Absorber Will Lead to Better Biosensor: Biosensors are more sensitive and able to detect smaller changes in the environment October 1st, 2014

Speed at its limits September 30th, 2014

'Pixel' engineered electronics have growth potential: Rice, Oak Ridge, Vanderbilt, Penn scientists lead creation of atom-scale semiconducting composites September 29th, 2014

Southampton scientists grow a new challenger to graphene September 23rd, 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