Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

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of fluorescence intensity by a factor of up to 108 compared with quantum dots on an unpatterned surface, more recent (unpublished) work has exceeded a factor of 550.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

Statement by QD Vision regarding European Parliament’s Vote on Cadmium-Based Quantum Dots May 20th, 2015

ORNL demonstrates first large-scale graphene fabrication May 14th, 2015

CLAIRE brings electron microscopy to soft materials: Berkeley researchers develop breakthrough technique for noninvasive nanoscale imaging May 14th, 2015

QD Vision to Showcase Quantum Dot “Firsts” at Display Week 2015: Executives will present, demo current and future quantum dot technology May 13th, 2015

Sensors

Technology for Tomorrow’s Market Opportunities and Challenges: LetiDays Grenoble Presents the Possibilities: June 24-25 Event Includes Focus on IoT-Augmented Mobility and Leti’s Latest Results on Silicon Technologies, Sensors, Health Applications and Smart Cities May 27th, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Record high sensitive Graphene Hall sensors May 21st, 2015

Graphene enables tunable microwave antenna May 15th, 2015

Discoveries

New technique speeds nanoMRI imaging: Multiplexing technique for nanoscale magnetic resonance imaging developed by researchers in Switzerland cuts normal scan time from two weeks to two days May 28th, 2015

Squeezed quantum cats May 28th, 2015

New chip makes testing for antibiotic-resistant bacteria faster, easier: Researchers at the University of Toronto design diagnostic chip to reduce testing time from days to one hour, allowing doctors to pick the right antibiotic the first time May 28th, 2015

Collaboration could lead to biodegradable computer chips May 28th, 2015

Quantum Dots/Rods

Statement by QD Vision regarding European Parliament’s Vote on Cadmium-Based Quantum Dots May 20th, 2015

Toward 'green' paper-thin, flexible electronics May 20th, 2015

Electricity generating nano-wizards: Quantum dots are an ideal nanolab to study the means to turning heat into electricity May 18th, 2015

QD Vision to Showcase Quantum Dot “Firsts” at Display Week 2015: Executives will present, demo current and future quantum dot technology May 13th, 2015

Photonics/Optics/Lasers

DNA Double Helix Does Double Duty in Assembling Arrays of Nanoparticles: Synthetic pieces of biological molecule form framework and glue for making nanoparticle clusters and arrays May 25th, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Samtec, Global Provider of Interconnect Systems, Joins IRT Nanoelec Silicon Photonics Program May 21st, 2015

Taking control of light emission: Researchers find a way of tuning light waves by pairing 2 exotic 2-D materials May 20th, 2015

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