Molecular Electronics Doped

Recent experiments have shown that the use of doping -- adding small amounts of impurities to the silicon to improve the flow of electricity through a semiconductor -- in molecular electronics could lead to the manufacture of components that are inexpensive, biodegradable and easier to manipulate.

Doping is already commonly used in today's electronics. But scientists at the Weizmann Institute of Science in Israel, working with colleagues in the US, recently succeeded in being the first to apply doping in molecular electronics -- the development of electronic components made of single layers of organic (carbon-based) molecules. Such components might be inexpensive, biodegradable, versatile and easy to manipulate, the researchers said.

The main problem with molecular electronics, they said, is that the organic materials must first be made sufficiently pure, and then ways must be found to successfully dope these somewhat delicate systems.

This is what professor David Cahen and postdoctoral fellow Oliver Seitz of the Weizmann Institute’s Material and Interfaces Department, together with Ayelet Vilan and Hagai Cohen from the Chemical Research Support Unit and professor Antoine Kahn from Princeton University, did. They showed that such "contamination" is possible after they successfully purified the molecular layer to such an extent that the remaining impurities did not affect the system’s electrical behavior.

The scientists doped the "clean" monolayers by irradiating the surface with ultraviolet light or weak electron beams, changing chemical bonds between the carbon atoms that make up the molecular layer. These bonds ultimately influenced electronic transport through the molecules.

This achievement was recently described in the Journal of the American Chemical Society. The researchers said they foresee that this method may enable scientists and electronics engineers to substantially broaden the use of these organic monolayers in the field of nanoelectronics.

"If I am permitted to dream a little, it could be that this method will allow us to create types of electronics that are different, and maybe even more environmentally friendly, than the standard ones that are available today," Seitz said.

For more information, visit: http://wis-wander.weizmann.ac.il/site/EN/homepage.asp