Featured Research

from universities, journals, and other organizations

Imaging tool may aid nanoelectronics by screening tiny tubes

Date:
November 17, 2010
Source:
Purdue University
Summary:
Researchers have demonstrated a new imaging tool for rapidly screening structures called single-wall carbon nanotubes, possibly hastening their use in creating a new class of computers and electronics that are faster and consume less power than today's.

Metallic and semiconducting single-wall carbon nanotubes are distinguished using a new imaging tool for rapidly screening the structures. The technology may hasten the use of nanotubes in creating a new class of computers and electronics that are faster and consume less power than those in use today.
Credit: Weldon School of Biomedical Engineering, Purdue University

Researchers have demonstrated a new imaging tool for rapidly screening structures called single-wall carbon nanotubes, possibly hastening their use in creating a new class of computers and electronics that are faster and consume less power than today's.

The semiconducting nanostructures might be used to revolutionize electronics by replacing conventional silicon components and circuits. However, one obstacle in their application is that metallic versions form unavoidably during the manufacturing process, contaminating the semiconducting nanotubes.

Now researchers have discovered that an advanced imaging technology could solve this problem, said Ji-Xin Cheng, an associate professor of biomedical engineering and chemistry at Purdue University.

"The imaging system uses a pulsing laser to deposit energy into the nanotubes, pumping the nanotubes from a ground state to an excited state," he said. "Then, another laser called a probe senses the excited nanotubes and reveals the contrast between metallic and semiconductor tubes."

The technique, called transient absorption, measures the "metallicity" of the tubes. The detection method might be combined with another laser to zap the unwanted metallic nanotubes as they roll off of the manufacturing line, leaving only the semiconducting tubes.

Findings are detailed in a research paper appearing online this week in the journal Physical Review Letters.

Single-wall nanotubes are formed by rolling up a one-atom-thick layer of graphite called graphene, which could eventually rival silicon as a basis for computer chips. Researchers in Cheng's group, working with nanomaterials for biomedical studies, were puzzled when they noticed the metallic nanoparticles and semiconducting nanowires transmitted and absorbed light differently after being exposed to the pulsing laser.

Then researcher Chen Yang, a Purdue assistant professor of physical chemistry, suggested the method might be used to screen the nanotubes for nanoelectronics.

"When you make nanocircuits, you only want the semiconducting ones, so it's very important to have a method to identify the metallic nanotubes," Yang said.

The paper was written by Purdue physics doctoral student Yookyung Jung; biomedical engineering research scientist Mikhail N. Slipchenko; Chang-Hua Liu, an electrical engineering graduate student at the University of Michigan; Alexander E. Ribbe, manager of the Nanotechnology Group in Purdue's Department of Chemistry; Zhaohui Zhong, an assistant professor of electrical engineering and computer science at Michigan; and Yang and Cheng. The Michigan researchers produced the nanotubes.

Semiconductors such as silicon conduct electricity under some conditions but not others, making them ideal for controlling electrical current in devices such as transistors and diodes.

The nanotubes have a diameter of about 1 nanometer, or roughly the length of 10 hydrogen atoms strung together, making them far too small to be seen with a conventional light microscope.

"They can be seen with an atomic force microscope, but this only tells you the morphology and surface features, not the metallic state of the nanotube," Cheng said.

The transient absorption imaging technique represents the only rapid method for telling the difference between the two types of nanotubes. The technique is "label free," meaning it does not require that the nanotubes be marked with dyes, making it potentially practical for manufacturing, he said.

The researchers performed the technique with nanotubes placed on a glass surface. Future work will focus on performing the imaging when nanotubes are on a silicon surface to determine how well it would work in industrial applications.

"We have begun this work on a silicon substrate, and preliminary results are very good," Cheng said.

Future research also may study how electrons travel inside individual nanotubes.

The research is funded by the National Science Foundation.


Story Source:

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


Journal Reference:

  1. Yookyung Jung, Mikhail N. Slipchenko, Chang Hua Liu, Alexander E. Ribbe, Zhaohui Zhong, Chen Yang, and Ji-Xin Chen. Fast Mapping of Metallicity in Individual Single-Walled Carbon Nanotubes Using a Transient Absorption Optical Microscope. Physical Review Letters, (in press)

Cite This Page:

Purdue University. "Imaging tool may aid nanoelectronics by screening tiny tubes." ScienceDaily. ScienceDaily, 17 November 2010. <www.sciencedaily.com/releases/2010/11/101116122855.htm>.
Purdue University. (2010, November 17). Imaging tool may aid nanoelectronics by screening tiny tubes. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2010/11/101116122855.htm
Purdue University. "Imaging tool may aid nanoelectronics by screening tiny tubes." ScienceDaily. www.sciencedaily.com/releases/2010/11/101116122855.htm (accessed October 22, 2014).

Share This



More Matter & Energy News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Internet of Things Aims to Smarten Your Life

Internet of Things Aims to Smarten Your Life

AP (Oct. 22, 2014) As more and more Bluetooth-enabled devices are reaching consumers, developers are busy connecting them together as part of the Internet of Things. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Newsy (Oct. 21, 2014) If you've ever watched "Back to the Future Part II" and wanted to get your hands on a hoverboard, well, you might soon be in luck. Video provided by Newsy
Powered by NewsLook.com
Robots to Fly Planes Where Humans Can't

Robots to Fly Planes Where Humans Can't

Reuters - Innovations Video Online (Oct. 21, 2014) Researchers in South Korea are developing a robotic pilot that could potentially replace humans in the cockpit. Unlike drones and autopilot programs which are configured for specific aircraft, the robots' humanoid design will allow it to fly any type of plane with no additional sensors. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Graphene Paint Offers Rust-Free Future

Graphene Paint Offers Rust-Free Future

Reuters - Innovations Video Online (Oct. 21, 2014) British scientists have developed a prototype graphene paint that can make coatings which are resistant to liquids, gases, and chemicals. The team says the paint could have a variety of uses, from stopping ships rusting to keeping food fresher for longer. Jim Drury reports. Video provided by Reuters
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