Atom für Atom zur perfekten LED

Atom by atom towards the perfect LED

© Daesung Park/TU Braunschweig
Atomic structure of the semiconductor gallium nitride, recorded with the TEM at TU Braunschweig.

Not all electron microscopes are the same. Since the first set-up in 1931, researchers have been working at great expense to achieve ever higher resolutions. The most powerful electron microscope at the TU Braunschweig, the TEM, is therefore completely sealed off from mechanical vibrations (such as trams rattling past) and magnetic fields (such as the earth’s magnetic field) at the LENA research centre.

With the titeling picture the Institute of Applied Physics of TU Braunschweig gives an insight into what the super device is capable of: the atomic structure of the semiconductor gallium nitride is finely lined up. As part of the QuantumFrontiers and Quantum Valley Lower Saxony, researchers from TU Braunschweig and the Physikalisch-Technische Bundesanstalt are jointly developing tiny blue LEDs from the material gallium nitride. During the complex LED production in the clean rooms of the Institute of Semiconductor Technology, gallium nitride is repeatedly fabricated, coated and etched. The researchers find out how good the next LED generation has become primarily through electron microscopy. The high-resolution TEM makes it possible for the scientists to go into detail, atom by atom, even with material samples that are already nanometres in size.

The image of the highresolution electron microscope is currently TU Braunschweig´s Picture of the Month.