Navigation Links
Sensing the infrared: Researchers improve IR detectors with single-walled carbon nanotubes
Date:5/23/2012

WASHINGTON, May 23Whether 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.

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.


'/>"/>
Contact: Angela Stark
astark@osa.org
202-416-1443
Optical Society of America
Source:Eurekalert  

Related biology technology :

1. Sensorin Raises Equity Financing to Launch Novel Industrial Sensing Venture
2. A revolutionary breakthrough in terahertz remote sensing
3. Novel electronic biosensing technology could facilitate new era of personalized medicine
4. A revolutionary breakthrough in terahertz remote sensing
5. Image Sensing Systems Announces First Quarter Financial Results
6. Biosensing tool to detect salmonella holds promise for preventing common food poisoning
7. Research at Rice University leads to nanotube-based device for communication, security, sensing
8. Understanding the science of solar-based energy: more researchers are better than one
9. Researchers decode viral process that prepares cells for HIV infection
10. Dartmouth researchers advance cellulosic ethanol production
11. Researchers develop new model for cystic fibrosis
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Sensing the infrared: Researchers improve IR detectors with single-walled carbon nanotubes
(Date:4/21/2017)... Austin, TX (PRWEB) , ... April 21, 2017 , ... ... more than a year, Formaspace is pleased to introduce it to top lab design ... Carolina. Formaspace CEO Jeff Turk and VP of Industrial Design and Engineering Greg Casey ...
(Date:4/21/2017)... ... 21, 2017 , ... Frederick Innovative Technology Center, Inc. (FITCI), ... and technology start-ups, is hosting “Celebration Friday” (a festive gathering highlighting client success ... libations and networking at 3:30 p.m. at FITCI’s 4539 Metropolitan Court location, off ...
(Date:4/20/2017)... INDIANAPOLIS , April 20, 2017  Eli Lilly ... Phase 2 data evaluating galcanezumab for the prevention of ... meeting, which will take place April 22-28, 2017, in ... will present four abstracts at AAN, including safety and ... and factors associated with a reduction in monthly migraine ...
(Date:4/20/2017)... 20, 2017 /PRNewswire/ - Prometic Life Sciences Inc. (TSX: PLI) (OTCQX: ... the International Liver Congress ("ILC") 2017 of the European Association ... Amsterdam on the positive effects of PBI-4050 on ... obesity and metabolic syndrome. ... According to Dr. Lyne Gagnon, Vice-President of R&D Pre-clinical of ...
Breaking Biology Technology:
(Date:4/4/2017)... YORK , April 4, 2017   EyeLock ... today announced that the United States Patent and Trademark ... patent broadly covers the linking of an iris image ... same transaction) and represents the company,s 45 th ... latest patent is very timely given the multi-modal biometric ...
(Date:3/30/2017)... LOS ANGELES , March 30, 2017  On ... Hack the Genome hackathon at ... This exciting two-day competition will focus on developing health ... experience. Hack the Genome is ... has been tremendous. The world,s largest companies in the ...
(Date:3/30/2017)... 2017 Trends, opportunities and forecast in this ... technology (fingerprint, AFIS, iris recognition, facial recognition, hand geometry, ... end use industry (government and law enforcement, commercial and ... and others), and by region ( North America ... Asia Pacific , and the Rest of the ...
Breaking Biology News(10 mins):