When the concept was first proposed, it was dismissed as being unrealizable: "It'll never work," commented one expert assessor of an application for research funding. Today, 15 years later, the physicist Professor Karl Leo and two of his colleagues have been presented with the Deutscher Zukunftspreis, one of Germany's most prestigious research awards, for what was once a highly controversial idea. Leo, director of the Fraunhofer Institute for Photonic Microsystems IPMS in Dresden, has devoted most of his career to organic electronics. Until now, most electronic components have been made of inorganic silicon. The brittle material is a good semiconductor, but its manufacture requires a highly sophisticated process. It involves growing large crystals at high temperatures and then cutting them into thin slices known as wafers.
The more elegant solution is to use an organic material, a type of dye commonly used in the production of road signs. Such materials have the advantage that they can be applied as a coating on flexible films and other substrates. This gives rise to endless new possibilities, such as displays that can be rolled up and carried in a vest pocket or switchable window panes that light up at night to illuminate rooms while hardly consuming any electricity. On the other hand, organic dyes are poor electrical conductors. But this is where the once-mocked ingenious idea comes into play: their less-than-satisfactory conductivity can be increased by doping, i.e. adding a small amount of another chemical substance. After years of experiments, the researchers have succeeded in creating materials with an electrical conductivity a million and more times greater than the original dyes, with a doping ratio of no more than one percent.
The Deutscher Zukunftspreis, endowed with 250,000 euros, has been awarded by the President of the Federal Republic of Germany every year since 1997. It honors outstanding innovations that have made the transitio
|Contact: Dr. Karl Leo|