Researcher investigates electronic properties of carbon nanotubes|
Posted 7/19/2007 Updated 7/20/2007
by Maria Callier
Air Force Office of Scientific Research Public Affairs
7/19/2007 - ARLINGTON, Va. -- Air Force Office of Scientific Research-funded analysis is creating transistors based on carbon nanotubes, ultrathin tubes of carbon a few atoms in width.
In discussing his research, Stanford University, Calif., team leader Dr. David Goldhaber-Gordon says that "Specifically, we are creating devices in which several ultra-fine metal wires are placed on top of a carbon nanotube to locally deplete electrons and create barriers for electron flow. Measuring electron flow across these barriers then reveals important information about the nature of electronic transport in one dimension.
"Such an understanding will be essential in reaching the ultimate limits of device miniaturization," said Mr. Goldhaber-Gordon, considered to be one of the United States' leading scientists in the field of condensed matter physics. "In addition to allowing manufacturers to pack more and more switches onto a single chip, device miniaturization via carbon nanotubes may help reduce power consumption and heat dissipation in these devices -- critical issues for many Air Force platforms, from manned fighter planes to autonomous drones."
The team is employing chemical vapor deposition, electron beam lithography, and atomic force microscopy to create nanotube devices. They conduct measurements at very low temperatures, just about two hundredths of one degree above absolute zero.
"This low temperature work helps clarify the basic science of electron flow in these systems, but we also study how behavior changes with temperature, all the way up to room temperature," Mr. Goldhaber-Gordon said.
Researchers say that carbon nanotubes will play a prominent role in the future of electronics, due to their exceptionally high electrical conductivity.
The research team's next steps are to study how electrons react to a possible barrier in a one-dimensional wire. There's been much speculation about that topic, but very few experiments until now.