Featured Research

from universities, journals, and other organizations

Effort May Sharpen Tracking Technology

Date:
July 15, 2004
Source:
University Of Southern California
Summary:
Researchers at USC and the University of Texas at Austin have built and tested a device based on nanostructures called quantum dots that can sensitively detect infrared radiation in a crucial wavelength range.

Engineers at USC and UT-Austin boost the sensitivity of night vision goggles and environmental monitors by using nanostructures known as quantum dots. Their invention could outperform existing detectors.
Credit: Image courtesy of University Of Southern California

Researchers at USC and the University of Texas at Austin have built and tested a device based on nanostructures called quantum dots that can sensitively detect infrared radiation in a crucial wavelength range.

Related Articles


The atmosphere is opaque to most infrared, but it is transparent for a narrow “window” between 8 and 12 microns. Night vision goggles, military target tracking devices and environmental monitors utilize this range of wavelengths.

Anupam Madhukar, holder of the Kenneth T. Norris Chair in the USC Viterbi School of Engineering with appointments in the departments of materials science, biomedical engineering and physics, said a class of existing infrared detectors is based on what is called ‘quantum well’ technology.

“We have created a detector based on different physics - quantum dot physics - that works at least as well and has the potential to perform better,” Madhukar said.

Madhukar worked with Joe C. Campbell, who holds the Cockrell Family Regents Chair in the UT Austin College of Engineering’s department of electrical and computer engineering. The two engineers described the device in a recent issue of Applied Physics Letters.

The device uses self-assembled “quantum dots,” island-like pyramidal structures made of semiconductors. Each dot has a core of indium arsenide surrounded by gallium arsenide and an indium-gallium arsenide alloy. A single dot is approximately 20 nanometers (2 millionths of a centimeter) in base size and about 4 nanometers in height.

The three-dimensional confinement of electrons within these structures creates unique, characteristic behavior. By using varying proportions of the materials and changing synthesis procedures, engineers can tailor quantum dots for use in lasers, detectors, optical amplifiers, transistors, tunneling diodes and other devices.

“Quantum dots are emerging as the most viable semiconductor nanotechnology for future higher-performance communication systems, biomedical imaging, environmental sensors and infrared detection,” Madhukar said.

Unlike their alternatives, quantum dot infrared detectors strongly absorb radiation shining perpendicular to the plane of an array of quantum dots.

By contrast, the alternate quantum well detectors don’t pick up radiation that shines straight down on them. To achieve this “necessitates additional processing steps,” Madhukar said. This increases the cost of the well detectors.

When the engineers benchmarked the new device using standard tests, its detectivity was nearly 100 times higher than the previously reported peak for quantum dot systems. The new range is competitive with the corresponding values for the well-established quantum well infrared photo detectors.

The U.S. Air Force Office of Scientific Research supported the research under the U.S. Department of Defense sponsored Multidisciplinary University Research Initiatives Program in Nanoscience.


Story Source:

The above story is based on materials provided by University Of Southern California. Note: Materials may be edited for content and length.


Cite This Page:

University Of Southern California. "Effort May Sharpen Tracking Technology." ScienceDaily. ScienceDaily, 15 July 2004. <www.sciencedaily.com/releases/2004/07/040714163330.htm>.
University Of Southern California. (2004, July 15). Effort May Sharpen Tracking Technology. ScienceDaily. Retrieved November 21, 2014 from www.sciencedaily.com/releases/2004/07/040714163330.htm
University Of Southern California. "Effort May Sharpen Tracking Technology." ScienceDaily. www.sciencedaily.com/releases/2004/07/040714163330.htm (accessed November 21, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Friday, November 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

NSA Director: China Can Damage US Power Grid

NSA Director: China Can Damage US Power Grid

AP (Nov. 20, 2014) China and "one or two" other countries are capable of mounting cyberattacks that would shut down the electric grid and other critical systems in parts of the United States, according to Adm. Michael Rogers, director of the National Security Agency and hea Video provided by AP
Powered by NewsLook.com
Latest Minivan Crash Tests Aren't Pretty

Latest Minivan Crash Tests Aren't Pretty

Newsy (Nov. 20, 2014) Five minivans were put to the test in head-on crash simulations by the Insurance Institute for Highway Safety. Video provided by Newsy
Powered by NewsLook.com
Takata Offers "sincerest Condolences" To Victims of Malfunctioning Airbag

Takata Offers "sincerest Condolences" To Victims of Malfunctioning Airbag

Reuters - US Online Video (Nov. 20, 2014) U.S. Congress hears from a victim and company officials as it holds a hearing on the safety of Takata airbags after reports of injuries. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
DARPA Creates The Tech You Can Only Dream Of

DARPA Creates The Tech You Can Only Dream Of

Newsy (Nov. 20, 2014) Curious what a rocket-dodging car would look like? How about a robotic pack mule? Or maybe a wearable robot? These are a few of DARPA's projects. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins