Molecular Electronics Doped
REHOVOT, Israel, July 30, 2007 -- 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
- 1. A constituent part. It may consist of two or more parts cemented together, or with near and approximately matching surfaces. 2. The projection of a vector on a certain coordinate axis or along a particular direction. 3. In a lens system, one or more elements treated as a unit. 4. An optical element within a system.
- The addition of impurities to another substance, usually solid, in a controlled manner that produces desired properties. Silicon doping with small amounts of other semimetallic elements increases the number of electrical carriers.
- A charged elementary particle of an atom; the term is most commonly used in reference to the negatively charged particle called a negatron. Its mass at rest is me = 9.109558 x 10-31 kg, its charge is 1.6021917 x 10-19 C, and its spin quantum number is 1/2. Its positive counterpart is called a positron, and possesses the same characteristics, except for the reversal of the charge.
- That branch of science involved in the study and utilization of the motion, emissions and behaviors of currents of electrical energy flowing through gases, vacuums, semiconductors and conductors, not to be confused with electrics, which deals primarily with the conduction of large currents of electricity through metals.
- The technology of generating and harnessing light and other forms of radiant energy whose quantum unit is the photon. The science includes light emission, transmission, deflection, amplification and detection by optical components and instruments, lasers and other light sources, fiber optics, electro-optical instrumentation, related hardware and electronics, and sophisticated systems. The range of applications of photonics extends from energy generation to detection to communications and...
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