Two breakthroughs achieved in single-molecule transistor research

June 12, 2002

How small can electronic devices get? Nano-small! Two teams of scientists have fashioned transistors from single molecules, and report their results in the June 13 issue of Nature.

The ability to use individual molecules for electronics is a coveted breakthrough for science at the nanometer scale and for electronics industries because of the potential to shrink the size of components well beyond what is possible using conventional lithography techniques.

Transistors, traditionally made from silicon, regulate the transmission of electrons across barriers. The barrier height, and hence the electron flow, can be controlled by applying a small voltage to an electrode that acts as a gate. At the Cornell University Center for Materials Research, funded by the National Science Foundation (NSF), Paul McEuen, Dan Ralph, Hector Abruna and colleagues wedged a molecule containing a single cobalt atom between gold electrodes. They were able, using a gate voltage, to control the transfer of electrons across the cobalt atom, demonstrating the ability to regulate electrical flow at the smallest possible scale.

Hongkun Park and coworkers at Harvard University developed a transistor by inserting a different molecule containing two atoms of the metal vanadium between gold electrodes. The scientists were able to start and stop the flow of electrical current by adjusting the voltage near the bridging molecule, and observed magnetic interactions between electrons in the gold and the vanadium atom.

Park's research was supported by individual NSF grants and by the NSF Center for the Science of Nanoscale Systems and their Device Applications at Harvard. The di-vanadium molecule was developed by NSF grantee Jeffrey Long at the University of California at Berkeley.

By demonstrating the ability to control electron flow across one molecule and even a single atom, scientists have become optimistic about the ability to someday build the smallest possible electronic components. An important aspect of the research is developing the ability to conduct electrical measurements at the nanoscale; for example, to measure the electrical properties of single molecules. Both of the NSFsupported experiments demonstrated this ability.
Additional media contacts:
David Brand, Cornell
(607) 255-3651/

For information on the materials center at Cornell, see:
For information on the nanoscience center at Harvard, see:

National Science Foundation

Related Nanoscale Articles from Brightsurf:

Nanoscale machines convert light into work
Researchers have developed a tiny new machine that converts laser light into work.

Discovery will allow more sophisticated work at nanoscale
The movement of fluids through small capillaries and channels is crucial for processes ranging from blood flow through the brain to power generation and electronic cooling systems, but that movement often stops when the channel is smaller than 10 nanometers.

Valley-Hall nanoscale lasers
Topological photonics allows the creation of new states of light.

Dynamics of DNA replication revealed at the nanoscale
Using super-resolution technology a University of Technology Sydney led team has directly visualised the process of DNA replication in single human cells.

House cleaning on the nanoscale
A team of scientists at Friedrich-Alexander Universität Erlangen-Nürnberg (FAU) has developed a novel mechanical cleaning method for surfaces on the nanoscale.

As electronics shrink to nanoscale, will they still be good as gold?
As circuit interconnects shrink to nanoscale, will the pressure caused by thermal expansion when current flows through wires cause gold to behave more like a liquid than a solid -- making nanoelectronics unreliable?

A joint venture at the nanoscale
Scientists at Argonne National Laboratory report fabricating and testing a superconducting nanowire device applicable to high-speed photon counting.

Bending diamond at the nanoscale
A team of Australian scientists has discovered diamond can be bent and deformed, at the nanoscale at least.

Creating a nanoscale on-off switch for heat
Researchers create a polymer thermal regulator that can quickly transform from a conductor to an insulator, and back again.

Magnetic tuning at the nanoscale
Physicists from the German research center Helmholtz-Zentrum Dresden-Rossendorf (HZDR) are working to produce engineered magnetic nanostructures and to tailor material properties at the nanoscale.

Read More: Nanoscale News and Nanoscale Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to