Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New nano-material combinations produce leap in infrared technology

15.02.2012
Arizona State University researchers are finding ways to improve infrared photodetector technology that is critical to national defense and security systems, as well as used increasingly in commercial applications and consumer products.

A significant advance is reported in a recent article in the journal Applied Physics Letters. It details discovery of how infrared photodetection can be done more effectively by using certain materials arranged in specific patterns in atomic-scale structures.

It's being accomplished by using multiple ultrathin layers of the materials that are only several nanometers thick. Crystals are formed in each layer. These layered structures are then combined to form what are termed "superlattices."

Photodetectors made of different crystals absorb different wavelengths of light and convert them into an electrical signal. The conversion efficiency achieved by these crystals determines a photodectector's sensitivity and the quality of detection it provides, explains electrical engineer Yong-Hang Zhang.

The unique property of the superlattices is that their detection wavelengths can be broadly tuned by changing the design and composition of the layered structures. The precise arrangements of the nanoscale materials in superlattice structures helps to enhance the sensitivity of infrared detectors, Zhang says.

Zhang is a professor in the School of Electrical, Computer and Energy Engineering, one of ASU's Ira A. Fulton Schools of Engineering. He is leading the work on infrared technology research in ASU's Center for Photonics Innovation. More information can be found at the center's Optoelectronics Group website at http://asumbe.eas.asu.edu/

Additional research in this area is being supported by a grant from the Air Force Office of Scientific Research and a new Multidisciplinary University Research Initiative (MURI) program established by the U.S. Army Research Office. ASU is a partner in the program led by the University of Illinois at Urbana-Champaign.

The MURI program is enabling Zhang's group to accelerate its work by teaming with David Smith, a professor in the Department of Physics in ASU's College of Liberal Arts and Sciences, and Shane Johnson, a senior research scientist in the ASU's engineering schools.

The team is using a combination of indium arsenide and indium arsenide antimonide to build the superlattice structures. The combination allows devices to generate photo electrons necessary to provide infrared signal detection and imaging, says Elizabeth Steenbergen, an electrical engineering doctoral student who performed experiments on the supperlattice materials with collaborators at the Army Research Lab.

"In a photodetector, light creates electrons. Electrons emerge from the photodetector as electrical current. We read the magnitude of this current to measure infrared light intensity," she says.

"In this chain, we want all of the electrons to be collected from the detector as efficiently as possible. But sometimes these electrons get lost inside the device and are never collected," says team member Orkun Cellek, an electrical engineering postdoctoral research associate.

Zhang says the team's use of the new materials is reducing this loss of optically excited electrons, which increases the electrons' carrier lifetime by more than 10 times what has been achieved by other combinations of materials traditionally used in the technology. Carrier lifetime is a key parameter that has limited detector efficiency in the past.

Another advantage is that infrared photodetectors made from these superlattice materials don't need as much cooling. Such devices are cooled as a way of reducing the amount of unwanted current inside the devices that can "bury" electrical signals, Zhang says.

The need for less cooling reduces the amount of power needed to operate the photodetectors, which will make the devices more reliable and the systems more cost effective.

Researchers say improvements can still be made in the layering designs of the intricate superlattice structures and in developing device designs that will allow the new combinations of materials to work most effectively.

The advances promise to improve everything from guided weaponry and sophisticated surveillance systems to industrial and home security systems, the use of infrared detection for medical imaging and as a road-safety tool for driving at night or during sand storms or heavy fog.

"You would be able to see things ahead of you on the road much better than with any headlights," Cellek says.

The research team's paper is reported on in the article "One giant leap for IR technology" on the LAB & FAB TALK website of Compound Semiconductor magazine: http://www.compoundsemiconductor.net/csc/news-details/id/19734460/name/One-giant-leap-for-IR-technolog.html

MEDIA CONTACT:
Joe Kullman, joe.kullman@asu.edu
(480) 965-8122 direct line
(480) 773-1364 mobile
Ira A. Fulton Schools of Engineering
Arizona State University
Tempe, Arizona USA
http://engineering.asu.edu/

Joe Kullman | EurekAlert!
Further information:
http://www.asu.edu

More articles from Interdisciplinary Research:

nachricht Bergamotene - alluring and lethal for Manduca sexta
21.04.2017 | Max-Planck-Institut für chemische Ökologie

nachricht How to color a lizard: From biology to mathematics
13.04.2017 | Université de Genève

All articles from Interdisciplinary Research >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>