
Breakthrough in Nanotechnology
Date: Thursday, April 17, 2008 @ 23:34:55 UTC Topic: Science
Researchers Make Breakthrough in Nanotechnology by Uncovering Conductive Property of Carbon-based Molecules
University of Pittsburgh researchers have discovered that certain
organic—or carbon-based—molecules exhibit the properties of atoms under
certain circumstances and, in turn, conduct electricity as well as
metal. Detailed in the April 18 edition of Science,
the finding is a breakthrough in developing nanotechnology that
provides a new strategy for designing electronic materials, including
inexpensive and multifunctional organic conductors that have long been
considered the key to smaller, cheaper, and faster technologies.
The Pitt team found that the hollow,
soccer-ball-shaped carbon molecules known as fullerenes can hold and
transfer an electrical charge much like the most highly conductive
atoms, explained project head Hrvoje Petek, a professor of physics and
chemistry in Pitt’s School of Arts and Sciences and codirector of
Pitt’s Petersen Institute for NanoScience and Engineering. The research
was performed by Pitt post-doctoral associates Min Feng and Jin Zhao.
When an electron was introduced into a fullerene molecule, the
shape of the electron distribution mimicked that of a hydrogen atom or
an atom from the alkali metal group, which includes lithium, sodium,
and potassium. Moreover, when two fullerenes were placed next to each
other on a copper surface, they showed the electron distribution of
their chemical bond and appeared as H2, a hydrogen molecule. The assembly exhibited metal-like conductivity when the team extended it to a wire 1-molecule-wide.
“Our work provides a new perspective on what determines the
electronic properties of materials,” Petek said. “The realization that
hollow molecules can have metal-like conductivity opens the way to
develop novel materials with electronic and chemical properties that
can be tailored by shape and size.”
Although the team worked with fullerenes, the team’s results apply
to all hollow molecules, Petek added, including carbon
nanotubes—rolled, 1-atom-thick sheets of graphite 100,000 times smaller
than a human hair.
The team’s research shows promise for the future
of electronics based on molecular conductors. These molecule-based
devices surpass the semiconductor and metal conductors of today in
terms of lower cost, flexibility, and the ability to meld the speed and
power of optics and electronics. Plus, unlike such inorganic conductors
as silicon, molecule-based electronics can be miniaturized to a
1-dimensional scale (1-molecule-wide), which may enable them to conduct
electricity with minimal loss and thus improve the performance of an
electronic device.
Traditionally, the problem has been that organic conductors have
not conducted electrical current very well, Petek said. The Pitt team’s
discovery could enable scientists to finally overcome that problem, he
added.
“Metal-like behavior in a molecular material—as we have found—is
highly surprising and desirable in the emerging field of molecular
electronics,” he said.
“Our work is a unique example of how nanoscale materials can be
used as atom-sized building blocks for molecular materials that could
replace silicon and copper in electronic devices, luminescent displays,
photovoltaic cells, and other technologies.”
Source: University of Pittsburgh Via: http://www.physorg.com/news127659085.html
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