Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Sensing the infrared: Researchers improve IR detectors with single-walled carbon nanotubes: New design eliminates need for complex, expensive cooling systems

This schematic shows the design of single-walled carbon nanotube photodetector, which provides a more efficient method of collecting infrared radiation without relying on cryogenics for cooling.

Credit: Image courtesy Sheng Wang, Peking University.
This schematic shows the design of single-walled carbon nanotube photodetector, which provides a more efficient method of collecting infrared radiation without relying on cryogenics for cooling.

Credit: Image courtesy Sheng Wang, Peking University.

Abstract:
Whether used in telescopes or optoelectronic communications, infrared detectors must be continuously cooled to avoid being overwhelmed by stray thermal radiation. Now, a team of researchers from Peking University, the Chinese Academy of Sciences, and Duke University (USA) is harnessing the remarkable properties of single-walled carbon nanotubes (SWNTs) to create highly sensitive, "uncooled" photovoltaic infrared detectors.

Sensing the infrared: Researchers improve IR detectors with single-walled carbon nanotubes: New design eliminates need for complex, expensive cooling systems

Washington, DC | Posted on May 23rd, 2012

This new type of detector, which the team describes in a paper published today in the Optical Society's (OSA) open-access journal Optical Materials Express, may prove useful for industrial, military, manufacturing, optical communications, and scientific applications.

Carbon nanotubes are known for their outstanding mechanical, electrical, and optical properties. "They also are an ideal nanomaterial for infrared applications," says Sheng Wang, an associate professor in the Department of Electronics at Peking University in Beijing, China, and an author of the Optical Materials Express paper. "For starters, these nanotubes exhibit strong and broadband infrared light absorption, which can be tuned by selecting nanotubes of different diameters. Also, due to their high electron mobility, nanotubes react very rapidly - on the order of picoseconds - to infrared light." In comparison to traditional infrared detectors, which are based on semiconductors made of a mercury-cadmium-telluride alloy, the SWNTs are an order of magnitude more efficient, the researchers report.

The team's photovoltaic infrared detector is formed by aligning SWNT arrays on a silicon substrate. The nanotubes arrays are then placed between asymmetric palladium and scandium contacts. These two metals have properties that collectively create what is known as an Ohmic contact, a region in a semiconductor device that has very low electrical resistance, which helps make the detector operate more efficiently.

"Fabrication of carbon nanotube infrared detectors can be readily implemented on a flexible substrate and large wafer at a low cost," explains Wang.

The detector demonstrated "acceptable sensitivity" at room temperature and may be significantly improved by increasing the density of the carbon nanotubes, according to the team. The signal-to-noise performance of conventional infrared photodetectors is limited by their natural infrared emission, which is subsequently absorbed by the detector. To avoid having this stray radiation overwhelm the detector, liquid nitrogen or electric cooling is generally used to suppress this thermal effect. However, this makes infrared detectors more complex and expensive to operate. The new design eliminates this need because carbon nanotubes have special thermal properties. At room temperature, they emit comparatively little infrared radiation of their own, especially when the carbon nanotube is on the substrate. In addition, nanotubes are very good at conducting heat, so temperatures do not build up on the detector itself.

One of the biggest surprises for the team was achieving relatively high infrared detectivity (the radiation power required to produce a signal from a photoconductor) using a carbon nanotube thin film only a few nanometers thick, Wang points out. Notably, conventional infrared detectors require much thicker films, on the scale of hundreds of nanometers, to obtain comparable detectivity.

Another huge advantage of the detector is that the fabrication process is completely compatible with carbon nanotube transistors - meaning no big expensive equipment changes are necessary. "Our doping-free chemical approach provides an ideal platform for carbon nanotube electronic and optoelectronic integrated circuits," says Wang.

The next step for the team is to focus on improving the detectivity of the detector with greater SWNT density, and to also achieve a wide spectrum response with improved diameter control.

####

About Optical Society of America
Uniting more than 130,000 professionals from 175 countries, the Optical Society (OSA) brings together the global optics community through its programs and initiatives. Since 1916 OSA has worked to advance the common interests of the field, providing educational resources to the scientists, engineers and business leaders who work in the field by promoting the science of light and the advanced technologies made possible by optics and photonics. OSA publications, events, technical groups and programs foster optics knowledge and scientific collaboration among all those with an interest in optics and photonics. For more information, visit www.osa.org.

About Optical Materials Express

Optical Materials Express (OMEx) is OSA's newest peer-reviewed, open-access journal focusing on the synthesis, processing and characterization of materials for applications in optics and photonics. OMEx, which launched in April 2011, primarily emphasizes advances in novel optical materials, their properties, modeling, synthesis and fabrication techniques; how such materials contribute to novel optical behavior; and how they enable new or improved optical devices. For more information, visit www.OpticsInfoBase.org/OMEx.

For more information, please click here

Contacts:
Angela Stark

202-416-1443

Copyright © Optical Society of America

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 Links

The paper, "Carbon Nanotube Arrays Based High-Performance Infrared Photodetector,"by Q. Zeng et al.:

Will appear in a special feature issue on "Nanocarbon for Photonics and Optoelectronics" in Vol. 2, Issue 6 of Optical Materials Express:

Related News Press

News and information

Electric-car battery materials could harm key soil bacteria February 11th, 2016

Creating a color printer that uses a colorless, non-toxic ink inspired by nature February 11th, 2016

SLAC X-ray laser turns crystal imperfections into better images of important biomolecules: New method could remove major obstacles to studying structures of complex biological machines February 11th, 2016

Nanoparticle reduces targeted cancer drug's toxicity February 11th, 2016

Chip Technology

Research reveals carbon films can give microchips energy storage capability: International team from Drexel University and Paul Sabatier University reveals versatility of carbon films February 11th, 2016

New thin film transistor may lead to flexible devices: Researchers engineer an electronics first, opening door to flexible electronics February 10th, 2016

SUNY Poly and GLOBALFOUNDRIES Announce New $500M R&D Program in Albany To Accelerate Next Generation Chip Technology: Arrival of Second Cutting Edge EUV Lithography Tool Launches New Patterning Center That Will Generate Over 100 New High Tech Jobs at SUNY Poly February 9th, 2016

Electron's 1-D metallic surface state observed: A step for the prediction of electronic properties of extremely-fine metal nanowires in next-generation semiconductors February 9th, 2016

Nanotubes/Buckyballs/Fullerenes

Superconductivity: Footballs with no resistance - Indications of light-induced lossless electricity transmission in fullerenes contribute to the search for superconducting materials for practical applications February 9th, 2016

The iron stepping stones to better wearable tech without semiconductors February 8th, 2016

Nano-coating makes coaxial cables lighter: Rice University scientists replace metal with carbon nanotubes for aerospace use January 28th, 2016

Scientists provide new guideline for synthesis of fullerene electron acceptors January 28th, 2016

Sensors

Scientists have put a high precision blood assay into a simple test strip: Researchers have developed a new biosensor test system based on magnetic nanoparticles February 3rd, 2016

Nanosheet growth technique could revolutionize nanomaterial production February 1st, 2016

New record in nanoelectronics at ultralow temperatures January 28th, 2016

NBC LEARN DEBUTS SIX-PART VIDEO SERIES, “NANOTECHNOLOGY: SUPER SMALL SCIENCE” Produced by NBC Learn in partnership with the National Science Foundation, and narrated by NBC News/MSNBC’s Kate Snow, series highlights leading research in nanotechnology January 25th, 2016

Discoveries

Research reveals carbon films can give microchips energy storage capability: International team from Drexel University and Paul Sabatier University reveals versatility of carbon films February 11th, 2016

Canadian Scientists Develop Innovative Protein Test for Zika February 11th, 2016

Creating a color printer that uses a colorless, non-toxic ink inspired by nature February 11th, 2016

SLAC X-ray laser turns crystal imperfections into better images of important biomolecules: New method could remove major obstacles to studying structures of complex biological machines February 11th, 2016

Announcements

Research reveals carbon films can give microchips energy storage capability: International team from Drexel University and Paul Sabatier University reveals versatility of carbon films February 11th, 2016

Creating a color printer that uses a colorless, non-toxic ink inspired by nature February 11th, 2016

SLAC X-ray laser turns crystal imperfections into better images of important biomolecules: New method could remove major obstacles to studying structures of complex biological machines February 11th, 2016

Nanoparticle reduces targeted cancer drug's toxicity February 11th, 2016

Energy

New thin film transistor may lead to flexible devices: Researchers engineer an electronics first, opening door to flexible electronics February 10th, 2016

Canadian physicists discover new properties of superconductivity February 8th, 2016

Host-guest nanowires for efficient water splitting and solar energy storage February 7th, 2016

February 4th, 2016

Solar/Photovoltaic

Host-guest nanowires for efficient water splitting and solar energy storage February 7th, 2016

Simplifying solar cells with a new mix of materials: Berkeley Lab-led research team creates a high-efficiency device in 7 steps January 29th, 2016

An alternative to platinum: Iron-nitrogen compounds as catalysts in graphene January 28th, 2016

Scientists provide new guideline for synthesis of fullerene electron acceptors January 28th, 2016

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







Car Brands
Buy website traffic