Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > A Nanowire with a Surprise

Abstract:
Scientists at the U.S. Department of Energy's Brookhaven National Laboratory and their collaborators have discovered that a short, organic chain molecule with dimensions on the order of a nanometer conducts electrons in a surprising way.

A Nanowire with a Surprise

New research may advance the nanoelectronics field

Upton, NY. October 18, 2004

Scientists at the U.S. Department of Energy's Brookhaven National Laboratory and their collaborators have discovered that a short, organic chain molecule with dimensions on the order of a nanometer (a billionth of a meter) conducts electrons in a surprising way: It regulates the electrons' speed erratically, without a predictable dependence on the length of the wire. This information may help scientists learn how to use nanowires to create components for a new class of tiny electronic circuits.

"This is a very unexpected and unique result," said John Smalley, a guest scientist in Brookhaven's Chemistry Department and the lead researcher of the study, described in the October 16, 2004, online edition of the Journal of the American Chemical Society.

The conducting chain molecule, or "nanowire," that Smalley and his collaborators studied is composed of units of phenyleneethynylene (PE), which consists of hydrogen and carbon atoms. Like the links that make up a chain, PE units join together to form a nanowire known as oligophenyleneethynylene (OPE). PE, and therefore OPE, contains single, double, and triple carbon-carbon bonds.

The double and triple carbon-carbon bonds promote strong electronic interactions along OPE such that it conducts an electric current with low electrical resistance. This property makes OPE nanowires good candidates for components in nanoelectronic circuits, very small, fast circuits expected to replace those currently used in computers and other electronics.

Smalley and his collaborators found that as they increased the length of the OPE wire from one to four PE units, the electrons moved across the wire faster, slower, then faster again, and so on. In this way, OPE does not behave like a similar nanowire the group has also studied, called oligophenylenevinylene (OPV), which contains single and double carbon-carbon bonds. When they made OPV wires longer, the electrons' speed remained the same. They observed the same result when they studied short wires made of alkanes, another group of hydrocarbon molecules that contains only single carbon-carbon bonds. The researchers think that the unusual behavior of OPE may be due to its tendency to slightly change its three-dimensional shape.

Increasing the wire's length may trigger new shapes, which may slow down or speed up the electrons as they cross the wire.

This variable resistance could be a benefit. "If the odd behavior is due to the conformational variability of the OPE wires, figuring out a way to control the tendency of OPE to change its shape could be useful," said Smalley. "For example, diodes and transistors are two types of devices based on variable electrical resistance."

The scientists made another significant finding: They dramatically increased the rate at which the electrons moved across the wire by substituting a methyl hydrocarbon group onto the middle unit of a three-unit OPE wire.

"Because OPE seems sensitive to this substitution, we hope to find another hydrocarbon group that may further increase the electrons' speed, and therefore OPE's ability to conduct electrons," said Smalley.

Experimental Background

In the experiment, Smalley and his group created an OPE wire "bridge" between a gold electrode and a "donor-acceptor" molecule. To measure the electron transfer rate across the bridge, they used a technique they developed in which a laser rapidly heats up the electrode. This causes a change in the electrical potential (voltage) between the electrode and the donor-acceptor, which disrupts the motion of electrons crossing the bridge. The group used a very sensitive voltmeter to measure how quickly the voltage changed in response to the altered electron movement. From these measurements, they determined how fast the electrons were moving through the wire.

This research, performed in collaboration with Marshall Newton of the Brookhaven Chemistry Department and researchers at Stanford University, Clemson University, and Motorola, is funded by the Office of Basic Energy Sciences within the U.S. Department of Energy's Office of Science and the National Science Foundation.

One of the ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

Visit Brookhaven Lab's electronic newsroom for links, news archives, graphics, and more: www.bnl.gov/newsroom.

Contact:

Laura Mgrdichian
631 344-8191
mgrdichian@bnl.gov

Mona S. Rowe
631 344-5056
mrowe@bnl.gov

Copyright © BNL

If you have a comment, please 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 News Press

Possible Futures

Two-dimensional bimetallic selenium-containing metal-organic frameworks and their calcinated derivatives as electrocatalysts for overall water splitting March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Chip Technology

New chip opens door to AI computing at light speed February 16th, 2024

HKUST researchers develop new integration technique for efficient coupling of III-V and silicon February 16th, 2024

Electrons screen against conductivity-killer in organic semiconductors: The discovery is the first step towards creating effective organic semiconductors, which use significantly less water and energy, and produce far less waste than their inorganic counterparts February 16th, 2024

NRL discovers two-dimensional waveguides February 16th, 2024

Nanoelectronics

Interdisciplinary: Rice team tackles the future of semiconductors Multiferroics could be the key to ultralow-energy computing October 6th, 2023

Key element for a scalable quantum computer: Physicists from Forschungszentrum Jülich and RWTH Aachen University demonstrate electron transport on a quantum chip September 23rd, 2022

Reduced power consumption in semiconductor devices September 23rd, 2022

Atomic level deposition to extend Moore’s law and beyond July 15th, 2022

Announcements

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project