What exactly is your doctoral project and what is so promising about it?
My doctorate is part of a large research project that aims to improve micro-acoustic high frequency filters. Everyone uses such filters on a daily basis during every form of wireless communication, for example while surfing the web or while calling someone. These filters use a piezoelectric material which sets the maximum bandwidth of the filter. The bandwidth, on the other hand, defines, among other things, how fast data can be transmitted. Considering that we want an increasingly faster internet connection, we require a much larger data rate and thus a much larger bandwidth, which is impossible to achieve with current electronic components. Therefore, a new material system is required for the next mobile radio standard 5G and that is what motivates my research.
For this purpose, I study thin layered aluminum scandium nitride and its pyroelectric characteristics. The striking qualities of this class of materials include piezoelectric properties and spontaneous polarization. This results in a consistent magnetic field without any external influence. These rare characteristics make it a promising new material system for the next generation of high frequency filters.
How did you come up with your topic?
I became aware of IAF during my college years at the KIT (Karlsruhe Institute of Technology). I visited a lecture held by Dr. Martin Walther, who also works at IAF, and at the end of the term we had an excursion to IAF. Their work immediately caught my attention, which is why I applied for my PhD at the institute after I finished my Master’s Degree in Physics. They proposed the topic to me, which originally was a project by the university of Freiburg. Therefore, I am actually enrolled at the university, but my workday is like anyone else’s at the institute, thanks to the great cooperation between IAF and the university.
What are the benefits of the cooperation between the IAF and the university?
I am already in the third year of my doctoral program and therefore almost finished. During the first two years I was exclusively at IAF. I was fully integrated and I could access all the resources of the institute. At the moment, however, I spend more and more time at the university, which is why I can evaluate quite well what kind of benefits the cooperation brings:
Fraunhofer IAF is very well equipped. The technical possibilities, especially of material production, exceed the university’s by far. Furthermore, the know-how in the specialized field of semiconductor materials is higher. The university, on the other side, has a much higher license pool due to its academic orientation. Thanks to my dual doctoral position, I can benefit from both, which is just perfect.