HELMHOLTZ Extreme

The smallest dunes

<b>An invasion from space?</b> The ion-source looks similar to a UFO in the graphic representation. With their ion-beam, research scientists are able to produce self-organised nano-structures.

It’s like a scene from a science-fiction film: A UFO shoots destructive beams and bores deep craters into the landscape. After the invasion, the world is a different place – it consists of well-ordered, long dunes.

In this case science-fiction and science are rather close together. But there was, of course, no UFO available for the research scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR); rather, there was a compact ion-source, from which electronically-charged particles – the ions – bubbled.
 
The research scientists wanted to find out what happens when ions are shot at gallium arsenide – a semi-conductor material from which, for example, light-emitting diodes (LEDs) are made. The ions destroyed the crystal structure of the material at room temperature. In order to avoid this, the researchers heated it up to 400° C. In this manner arsenic atoms were detached and the remaining gallium atoms spontaneously organised themselves into long rows – or figuratively speaking into nano-dunes. All of this took place in the unimaginably narrow range of 30 nanometres, whereby a nanometre is one-millionth of a millimetre.

With this experiment the physicists have opened a new chapter in the manufacture of nanostructures. Such surfaces play an important role in the construction of micro-electronic circuits and transistors. “Through spontaneous self-organisation, nano-structures can be produced much quicker than previously,” says HZDR research scientist Stefan Facsko. He already has a concrete application for the new procedure in mind – production of optical grids for ultraviolet light sources. These grids filter out the wave-length range from the light spectrum that researchers need for art-historical investigations of paintings, for example.

You can access all archived editions of HELMHOLTZ extreme here: www.helmholtz.de/extreme

30.10.2015 , Silvia Zerbe
Readers Comments, discuss with us (0)
No comments found!
Add comment

Ihr Kommentar wird nach dem Absenden durch unsere Redaktion geprüft und dann freigegeben, wir bitten um etwas Geduld. Bitte beachten Sie auch unsere Kommentarregeln.

Your comment will be checked by our editors after sending and then released, we ask you for a little patience.

Print Version