Nanotech has taken a major step along the road to molecular electronics with the demonstration that one molecule of benzene can form a highly conductive junction between two platinum electrodes. From an article on nanotechweb.org, written by Belle Dumé (requires free registration) “Ballistic breakthrough could lead to molecular logic gates“:
The first highly-conductive connection between a single organic molecule and a metal electrode has been made by an international team of physicists. This achievement could lead to the development of ‘molecular electronics’ devices with the potential to be smaller and faster than conventional transistors and logic gates.
The majority of electronic devices are made from just a handful of semiconductor materials — the most common being silicon. However, some organic molecules such as DNA appear to have electronic properties similar to traditional semiconductors and some researchers believe that some types of molecules could be used to make electronic devices.
A potential benefit of such devices is that molecules are extremely small compared to semiconductor structures, which could help manufacturers pack more and more circuits onto a chip.
However, it has proven very difficult to connect single molecules to a metal electrode such that electrons are conducted easily between the two. These junctions are essential for making real-world devices like transistors and logic gates.
…Now, Jan van Ruitenbeek of the University of Leiden in the Netherlands along with colleagues in Australia, Germany and Spain may have solved this problem by making the first highly conductive molecular junctions. This involved binding benzene molecules directly to platinum metal electrodes, and the team found that the conductance of these devices reaches the maximum value possible for a single electron channel.
…”What makes this work stand out is that [the scientists] have presented a new way to attach organic molecules to metal electrodes, by forming a direct metal-carbon bond, and have proven conclusively that their devices have a strong metal-molecule link,” commented Latha Venkataraman of Columbia University in an American Physical Society Viewpoint article on the research. “This enables them to overcome a major barrier in molecular based devices,” she said.
The research was published in Physical Review Letters (abstract).