Posted: November 18, 2009

Passing current through touching molecules

(Nanowerk News) The charge flow from a single C60 molecule to another one has been probed. Due to the constantly progressing miniaturization of electronic components, the performance of modern electronics could continuously be enhanced. However, when trying to further shrink the tiny nano-scaled structures, severe obstacles have appeared. Now for the first time, a European research cooperation has succeeded in constructing an electrical circuit consiting of two single molecules and probe its electrical properties.
The results obtained by the German, French, Spanish and Danish researchers are presented in the recent issue of the renowned PhysicalReview Letters journal ("Passing Current through Touching Molecules"). The scientists employed football-shaped C60-molecules that were a billionth of a meter in diameter and promised great potential for technical applications in materials science and nanotechnology, owing to its chemical and physical qualities.
Initially, the scientists lifted up one of the molecules with the tip of a scanning tunnelling microscope, then moved it towards another molecule with a precision of few quadrillionths meter.
During this approach, the physicists managed to probe the charge flow between the two molecules. Understanding this electric current, which depends strongly on the molecules’ distance, is indispensable for future molecule-based electronics.
The experiment shows that the conductivity between the tangent molecules is a hundred times lower than for a single C60-molecule and therefore allows only for very weak electric current.
This result is crucial for modern nanoelectronics, which will incorporate very closely arranged molecules, for unintentional short-circuits can be brought under control through certain molecular characteristics. Additionally carried out quantum mechanic calculations are in line with the experimental results and also predict a merely small conductivity.
The newly gained insight into nano-scaled electric charge flow is an important step for the design of molecular electronics. Furthermore,the extreme precision of manipulation and control of single molecules presented by the scientists discloses new ways for exploring nanoelectronic components.
Source: Kompetenznetze Deutschland