Yale Research On Molecular Switches May Lead To Smaller, Cheaper Computers

The vast improvements and reduced cost seen in computers and electronics over the last three decades will eventually stop because circuits can¹t be made smaller. Scientists have been trying to devise ways to address this problem for years. For the first time, the Yale research team has identified a reversible electronic switch that is the size of a single molecule.

"The ultimate for shrinking the size of a switch is the molecular level, which this study demonstrates," said Mark Reed, Harold Hodgkinson Professor of Engineering and Applied Science and chair of electrical engineering at Yale. "We also did it using a fabrication method which has the potential to radically reduce the cost of future microcircuits."

Published in the November 19 issue of Science, the study looks at large reversible switching behavior in nanoscale electronic devices that use molecules as the active component. The devices show a thousand-fold on/off ratio. These are comparable to or exceed more conventional types of electronic devices.

In addition to shrinking the size of the switch to atomic dimensions, the researchers also used a fabrication method called "self assembly," where the device actually self-forms, in comparison to conventional methods of transistor fabrication using lithography.

"The combination of the small size and the use of self-assembly has the potential to cause a discontinuity in the economics of microcircuitry," said Reed. "Although there are a host of engineering challenges to bring this to a manufacturable technology, this study demonstrates the principle and the fundamental limits of what can be done."

The research team consisted of Reed and graduate student Jia Chen in Yale¹s electrical engineering department; and Professor James Tour and graduate student Adam Rawlett of the Department of Chemistry and Center for Nanoscale Science and Technology at Rice University.