Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



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 4×1010 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

Multiphoton polymerization: A promising technology for precision medicine February 28th, 2025

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

SMART researchers pioneer first-of-its-kind nanosensor for real-time iron detection in plants February 28th, 2025

How a milk component could eliminate one of the biggest challenges in treating cancer and other disease, including rare diseases: Nebraska startup to use nanoparticles found in milk to target therapeutics to specific cells January 17th, 2025

Discoveries

Development of 'transparent stretchable substrate' without image distortion could revolutionize next-generation displays Overcoming: Poisson's ratio enables fully transparent, distortion-free, non-deformable display substrates February 28th, 2025

Unraveling the origin of extremely bright quantum emitters: Researchers from Osaka University have discovered the fundamental properties of single-photon emitters at an oxide/semiconductor interface, which could be crucial for scalable quantum technology February 28th, 2025

Closing the gaps — MXene-coating filters can enhance performance and reusability February 28th, 2025

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

Announcements

Development of 'transparent stretchable substrate' without image distortion could revolutionize next-generation displays Overcoming: Poisson's ratio enables fully transparent, distortion-free, non-deformable display substrates February 28th, 2025

Unraveling the origin of extremely bright quantum emitters: Researchers from Osaka University have discovered the fundamental properties of single-photon emitters at an oxide/semiconductor interface, which could be crucial for scalable quantum technology February 28th, 2025

Closing the gaps — MXene-coating filters can enhance performance and reusability February 28th, 2025

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

Military

Quantum engineers ‘squeeze’ laser frequency combs to make more sensitive gas sensors January 17th, 2025

Chainmail-like material could be the future of armor: First 2D mechanically interlocked polymer exhibits exceptional flexibility and strength January 17th, 2025

Single atoms show their true color July 5th, 2024

NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024

Aerospace/Space

Flexible electronics integrated with paper-thin structure for use in space January 17th, 2025

The National Space Society Congratulates SpaceX on Starship’s 7th Test Flight: Latest Test of the Megarocket Hoped to Demonstrate a Number of New Technologies and Systems January 17th, 2025

The National Space Society Congratulates Blue Origin on the Inaugural Flight of New Glenn: The Heavy Lift Reusable Rocket Will Open New Frontiers and Provide Healthy Competition January 17th, 2025

Bringing the power of tabletop precision lasers for quantum science to the chip scale December 13th, 2024

Quantum Dots/Rods

A new kind of magnetism November 17th, 2023

IOP Publishing celebrates World Quantum Day with the announcement of a special quantum collection and the winners of two prestigious quantum awards April 14th, 2023

Qubits on strong stimulants: Researchers find ways to improve the storage time of quantum information in a spin rich material January 27th, 2023

NIST’s grid of quantum islands could reveal secrets for powerful technologies November 18th, 2022

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