Dr Jannic Wolf, a chemist at the University of Konstanz, has discovered that a diarylethene compound is a suitable molecule. Measuring approximately 3nm, the molecule rotates very little when a point in its structure opens and there are two nanowires that can be used as contacts. The molecule is an insulator when open and becomes a conductor when closed.
Already, the team has managed to switch the current flow through the molecule with the help of light. HZDR physicist Dr Artur Erbe said: "We developed a nanotechnology that relies on extremely thin tips made of very few gold atoms. We stretch the switchable diarylethene compound between them."
When light hits the molecule, it switches from its open to its closed state, resulting in a current flowing. "For the first time, we could switch on a single contacted molecule and prove that this precise molecule becomes a conductor," Dr Erbe noted. "We have also characterised the molecular switching mechanism in detail, which is why I believe that we have succeeded in making an important step toward a genuine molecular electronic component."
One area of research focus in Dresden is self organisation. "DNA molecules are, for instance, able to arrange themselves into structures without any outside assistance. If we succeed in constructing logical switches from self organising molecules, then computers of the future will come from test tubes," Dr Erbe added.
