Researchers show how GaAs nanowires form
In an article in Nature this week, scientists at Lund University, Sweden collaborating with researchers at the IBM T. J. Watson Research Center, USA, and Cambridge University, UK, have shown how different arrangements of atoms can be combined into nanowires as they grow.
In the study 'Interface Dynamics and Crystal Phase Switching in GaAs Nanowires', the researchers were able to monitor in real time where each new atomic layer is placed in a growing nanowire, and explain why they place themselves where they do.
They say that learning to control the properties of materials this way can lead the way to more efficient electronic devices.
"We now have on tape the events that take place, and what is required to be able to control the nanowire growth", says Daniel Jacobsson, former doctoral student at the Lund University Faculty of Engineering, and currently a research engineer at the Lund University Centre for Chemistry and Chemical Engineering.
The team wanted to understand how nanowires grow, and chose to film them though an electron microscope. The article in Nature is about these films, which show nanowires made from GaAs and composed of different crystal structures.
"The nanowires grow through a self-assembly process which is spontaneous and hard to control. But if we can understand how the nanowires grow, we can control the structures that are formed in a more precise way, and thereby create new types of structures for new fields of application", says Daniel Jacobsson.
At the Centre for Chemistry and Chemical Engineering in Lund, a world-leading 'super microscope' is under construction, which will be able to show, in high resolution, how atoms are joined together when nanostructures are formed.
"In our Nature article, we show how dynamic the growth of nanowires really is. Once the new microscope is in place, we hope to be able to provide even more details and expand the scope of materials studied. Both the current results, and hopefully those to come, are important for an even more exact formation of nanowires for various applications", says Kimberly Dick Thelander.
