Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Making strides in quantum dot infrared photodetectors

Abstract:
Researchers at Northwestern University have made significant strides in the development of quantum dot infrared photodetectors -- technology that may provide new imaging techniques with applications in medical and biological imaging, environmental and chemical monitoring, night vision and infrared imaging from space.

Making strides in quantum dot infrared photodetectors

EVANSTON, IL | Posted on May 17th, 2007

Conventional infrared photon detector technology for imaging applications typically requires that the detector be cooled to very low temperatures -- approximately 77 degrees Kelvin. This cooling requirement adds significant cost, bulk and power consumption to the imaging systems, therefore limiting their usability. By using nanotechnology to form quantum dots, researchers at Northwestern's Center for Quantum Devices (CQD) are one step closer to achieving the goal of developing high-performance imaging techniques that can operate at higher temperatures.

Quantum dots, also known as "artificial atoms," have been widely investigated as a means of improving a variety of electronic and optoelectronic devices. The small size of quantum dots, usually around 10 nanometers, gives them a unique physical property of three-dimensional confinement, which can enable higher operating temperatures when used in infrared detector design.

"The development of an infrared photon detector that can operate at higher temperatures will enable the use of cheaper, lighter and more efficient cooling methods in the design of infrared imaging systems," said Manijeh Razeghi, Walter P. Murphy Professor of Electrical Engineering and Computer Science and director of the Center for Quantum Devices. "This will allow the use of infrared detectors in a much wider range of applications."

Researchers at CQD made a great breakthrough in the development of high-performance quantum dot infrared photodetectors (QDIP). They have developed a QDIP that operates at room temperature with a peak detection wavelength in the technologically important middle wavelength infrared window -- wavelengths between three and five microns are important because they are not susceptible to absorption by Earth's atmosphere. The QDIP is based on a hybrid indium arsenide quantum dot and an indium gallium arsenide quantum well structure grown on an indium phosphide substrate.

The specific detectivity and quantum efficiency at 150 degrees Kelvin were 41010 cmHz1/2/W and 35 percent, respectively. This record high performance was published in the March 26, 2007, issue of Applied Physics Letters, Vol. 90 No. 13. In devices developed since publication, the performance was further improved with a quantum efficiency of 48 percent through the optimization of the quantum dot growth, which led to stronger infrared absorption.

Researchers at CQD have used this technology to build an infrared camera, or focal plane array (FPA), based on this device. Thermal imaging was demonstrated at temperatures up to 200 degrees Kelvin -- the highest ever demonstrated for a QDIP focal plan array.

A paper on this work was published in the May 14, 2007, issue of Applied Physics Letters, Vol. 90 No. 20.

This work was presented at the 25th Annual Army Research Conference in November 2006 and won a Best Paper Award at the conference. This work also was presented as an invited talk at the SPIE Defense and Security Symposium in April 2007 and was presented at the 8th International Conference on Mid-Infrared Optoelectronics: Materials and Devices in May 2007.

####

For more information, please click here

Contacts:
Megan Fellman

847-491-3115

Copyright © Northwestern University

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

Nanomedicine

The thunder god vine, assisted by nanotechnology, could shake up future cancer treatment: Targeted therapy for hepatocellular carcinoma using nanotechnology August 27th, 2014

Introducing the multi-tasking nanoparticle: Versatile particles offer a wide variety of diagnostic and therapeutic applications August 26th, 2014

Symphony of nanoplasmonic and optical resonators leads to magnificent laser-like light emission August 26th, 2014

Silver Replaced with Copper Nanoparticles to Produce Antibacterial Fabrics August 25th, 2014

Discoveries

The thunder god vine, assisted by nanotechnology, could shake up future cancer treatment: Targeted therapy for hepatocellular carcinoma using nanotechnology August 27th, 2014

Creation of a Highly Efficient Technique to Develop Low-Friction Materials Which Are Drawing Attention in Association with Energy Issues August 26th, 2014

Competition for Graphene: Berkeley Lab Researchers Demonstrate Ultrafast Charge Transfer in New Family of 2D Semiconductors August 26th, 2014

Symphony of nanoplasmonic and optical resonators leads to magnificent laser-like light emission August 26th, 2014

Announcements

The thunder god vine, assisted by nanotechnology, could shake up future cancer treatment: Targeted therapy for hepatocellular carcinoma using nanotechnology August 27th, 2014

Creation of a Highly Efficient Technique to Develop Low-Friction Materials Which Are Drawing Attention in Association with Energy Issues August 26th, 2014

Competition for Graphene: Berkeley Lab Researchers Demonstrate Ultrafast Charge Transfer in New Family of 2D Semiconductors August 26th, 2014

Symphony of nanoplasmonic and optical resonators leads to magnificent laser-like light emission August 26th, 2014

Military

Introducing the multi-tasking nanoparticle: Versatile particles offer a wide variety of diagnostic and therapeutic applications August 26th, 2014

Biomimetic photodetector 'sees' in color: Rice lab uses CMOS-compatible aluminum for on-chip color detection August 25th, 2014

New material could enhance fast and accurate DNA sequencing August 13th, 2014

On the frontiers of cyborg science August 10th, 2014

Aerospace/Space

Creation of a Highly Efficient Technique to Develop Low-Friction Materials Which Are Drawing Attention in Association with Energy Issues August 26th, 2014

Thermal Block Coatings Developed in Iran Using Nanotechnology August 26th, 2014

The International Space Elevator Consortium (ISEC) is proud to announce the 2014 Space Elevator Conference! This annual event will be held at the Museum of Flight in Seattle, Washington from Friday, August 22nd through Sunday, August 24th August 19th, 2014

Life on Mars? Implications of a newly discovered mineral-rich structure August 19th, 2014

Quantum Dots/Rods

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

NANOPARTICLES INDIA August 8th, 2014

Researchers create quantum dots with single-atom precision June 30th, 2014

New Los Alamos Approach May Be Key to Quantum Dot Solar Cells With Real Gains in Efficiency: Nanoengineering Boosts Carrier Multiplication in Quantum Dots June 19th, 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