Featured Research

from universities, journals, and other organizations

Linear Arrays Of Nanotubes Offer Path To High-performance Electronics

Date:
April 2, 2007
Source:
University of Illinois at Urbana-Champaign
Summary:
Despite the attractive electrical properties and physical features of single-walled carbon nanotubes, incorporating them into scalable integrated circuits has proven to be a challenge because of difficulties in manipulating and positioning these molecular scale objects and in achieving sufficient current outputs. Researchers have now developed an approach that uses dense arrays of aligned and linear nanotubes as a thin-film semiconductor material suitable for integration into electronic devices.

Scanning electron microscope image of a pattern of aligned, linear single-walled carbon nanotubes formed by chemical vapor deposition growth on a quartz substrate. The bright horizontal stripes correspond to the regions of iron catalyst.
Credit: John A. Rogers

Despite the attractive electrical properties and physical features of single-walled carbon nanotubes, incorporating them into scalable integrated circuits has proven to be a challenge because of difficulties in manipulating and positioning these molecular scale objects and in achieving sufficient current outputs.

Now, researchers at the University of Illinois, Lehigh University and Purdue University have developed an approach that uses dense arrays of aligned and linear nanotubes as a thin-film semiconductor material suitable for integration into electronic devices.

The nanotube arrays can be transferred to plastic and other unusual substrates for applications such as flexible displays, structural health monitors and heads-up displays. The arrays also can be used to enhance the performance of devices built with conventional silicon-based chip technology.

"The aligned arrays represent an important step toward large-scale integrated nanotube electronics," said John A. Rogers, a Founder Professor of Materials Science and Engineering at Illinois, and corresponding author of a paper accepted for publication in the journal Nature Nanotechnology, and posted on its Web site.

To create nanotube arrays, the researchers begin with a wafer of single-crystal quartz, on which they deposit thin strips of iron nanoparticles. The iron acts as a catalyst for the growth of carbon nanotubes by chemical vapor deposition. As the nanotubes grow past the iron strips, they lock onto the quartz crystal, which then aligns their growth.

The resulting linear arrays consist of hundreds of thousands of nanotubes, each approximately 1 nanometer in diameter (a nanometer is 1 billionth of a meter), and up to 300 microns in length (a micron is 1 millionth of a meter). The nanotubes are spaced approximately 100 nanometers apart.

The arrays function as an effective thin-film semiconductor material in which charge moves independently through each of the nanotubes. In this configuration, the nanotubes can be integrated into electronic devices in a straightforward fashion by conventional chip-processing techniques.

A typical device incorporates approximately 1,000 nanotubes, and can produce current outputs 1,000 times higher than those of previously reported devices that incorporate just a single nanotube. Many devices can be built from each array, with good device-to-device uniformity. Detailed theoretical analysis of these unusual devices reveals many aspects of their operation.

Using the arrays, the researchers built and tested a number of transistors and logic gates, and compared the properties of nanotube arrays with those of individual nanotubes.

"This is the first study that shows properties in scalable device configurations that approach the intrinsic properties of the tubes themselves, as inferred from single-tube studies," said Rogers, who also is a researcher at the university's Beckman Institute.

Nanotube arrays aren't likely to replace silicon, Rogers said, but could be added to a silicon chip and exploited for particular purposes, such as higher speed operation, higher power capacity and linear behavior for enhanced functionality. They can also be used in applications such as flexible devices, for which silicon is not well suited.

"Nanotubes have shown potential in the past, but there hasn't been a clear path from science to technology," said Moonsub Shim, a professor of materials science and engineering at Illinois, and a co-author of the paper. "Our work seeks to bridge this gap."

With Rogers and Shim, co-authors of the paper are postdoctoral research associate Seong Jun Kang and graduate students Coskun Kocabas and Taner Ozel, all at Illinois; electrical and computer engineering professor Muhammad A. Alam and graduate student Ninad Pimparkar at Purdue, and physics professor Slava V. Rotkin at Lehigh.

The National Science Foundation and the U.S. Department of Energy funded the work.


Story Source:

The above story is based on materials provided by University of Illinois at Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University of Illinois at Urbana-Champaign. "Linear Arrays Of Nanotubes Offer Path To High-performance Electronics." ScienceDaily. ScienceDaily, 2 April 2007. <www.sciencedaily.com/releases/2007/03/070326095731.htm>.
University of Illinois at Urbana-Champaign. (2007, April 2). Linear Arrays Of Nanotubes Offer Path To High-performance Electronics. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2007/03/070326095731.htm
University of Illinois at Urbana-Champaign. "Linear Arrays Of Nanotubes Offer Path To High-performance Electronics." ScienceDaily. www.sciencedaily.com/releases/2007/03/070326095731.htm (accessed July 31, 2014).

Share This




More Matter & Energy News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
Smartphone Powered Paper Plane Debuts at Airshow

Smartphone Powered Paper Plane Debuts at Airshow

AP (July 30, 2014) Smartphone powered paper airplane that was popular on crowdfunding website KickStarter makes its debut at Wisconsin airshow (July 30) Video provided by AP
Powered by NewsLook.com
U.K. To Allow Driverless Cars On Public Roads

U.K. To Allow Driverless Cars On Public Roads

Newsy (July 30, 2014) Driverless cars could soon become a staple on U.K. city streets, as they're set to be introduced to a few cities in 2015. 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:
from the past week

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