In conversation with Philipp Döring

You have a joint position as a PhD student and research associate at two institutes. How does the cooperation of the Fraunhofer IAF and the INATECH work and which benefits come along with it?

I work at both institutes. At the beginning, during my literature review phase, I was practically full-time at the INATECH. Meanwhile, I am almost exclusively at the Fraunhofer IAF, conducting the practical part of my research. The idea behind the dual concept of my position is the exchange between the university and the Fraunhofer Institute, as well as the promotion of young researchers. As a PhD student, this is an advantage, as the IAF has a considerable know-how in specific areas, for example in my research field, gallium nitride.


How did you come to write your doctorate in the field of power electronics? Have you always dreamt of working with electronic circuits and components?

Frankly, not at all. My father has studied automation technology and tried to raise my enthusiasm for microelectronics, but at that time I considered it quite boring. I started my academic career by studying Earth Science. Over time I extended my area of studies towards material science. As a result of my new found interest, I went on to do my Master’s degree in Sustainable Materials. Eventually, I found my way to power electronics during my work on my Master’s thesis, in which my second supervisor Prof. Dr. Oliver Ambacher, the director of the Fraunhofer IAF and professor at the University of Freiburg, raised my interest in the topic.


What exactly is the topic of your doctorate and what fascinates you about it?

My topic deals with vertical gallium nitride transistors. This technology has been researched very little up to now. Despite the fact that transistors based on gallium nitride are well known at the IAF, vertical transistors are relatively new and have not been researched in Germany till now. The lack of experience in this area makes it exciting and offers various starting points for my research. For instance, in the material development and in the areas of process development many obstacles still need to be overcome.

Vertical transistors are fascinating, since in comparison to established lateral transistors they have less limits considering their power. In other words, you can channel more power through them, which makes them especially promising for applications in data centers, automotive and telecommunications industry. However, a lot of development work will be necessary, in order to put the theoretical potential of a vertical layout to use. Yet, this step is what excites me the most. For me it is thrilling to see, whether a plan works out, or not. I have to choose all the components I need for a vertical transistor, put them together and check whether it works, how it works and how well it works.

© Fraunhofer IAF

Considering that it’s the practical work you enjoy most, why did you came to the IAF instead of working in the industry?

As far as I can judge, you have just as much practical work here at the IAF as a position in a company would offer you. Practical applications are essential for a research and development institute. Furthermore, I have a lot of freedom in my research, while at the same time profiting from high industrial standards and regulated processes here at the IAF.


Being a PhD student and employee at the same time, what tasks do you have alongside your own research?

I have to help with other projects of the INATECH. These do not exactly cover my research topic, but belong to the same area. Another task is the support of graduates. The INATECH has several students and one of them is going to write his Master’s thesis on vertical transistors. He will start next month at the Fraunhofer IAF and his work will be synchronized with the current state of my research. Together with my colleagues at the IAF I will supervise him and by those means, we both benefit from the teamwork.


Which piece of advice would you give to an undergraduate or graduate student?

They should definitely not put too much pressure on themselves. I consider it very important, not to emphasize grades too much. After all, it is not about getting straight A’s, but to learn what you are really interested in during your studies. In the end, you should not study for the grades, but because you enjoy doing it!

Furthermore, I would emphasize practical experience. They should get a picture of how work and a possible job looks like. You will not write exams during your work life, but you will need to be able to put to use what you have learned. Only by practical experiences it is possible to get to know your talent and what kind of work you enjoy. Working as a student assistant is one possible way, another one is to do an internship at a company. Best would be to do both, in order to see whether you tend towards university research or a career in the industry.

© Fraunhofer IAF

What do you particularly appreciate about Freiburg and its surroundings?

I like the city itself very much. I appreciate that it is neither very big, nor very small. Another benefit is that I live right in the center of the city, yet I am very fast out in the nature. Until now, I haven’t found any city as beautiful as Freiburg.


What has been your personal highlight at the Fraunhofer IAF so far?

On my first day at the institute I took part in a tour around the clean room. It was very special seeing all the instruments and it motivated me to work with them. Furthermore, I got the feeling that it will be a very exciting time at the Fraunhofer IAF.


How would you describe the Fraunhofer IAF briefly in three words?

Together: I could always ask my coworkers for advice.

Atmosphere: There is a very good vibe between the colleagues.

Scientist’s playground: There are almost no limits for scientists at the IAF. Here, the only limiting factor is yourself. There is every necessary instrument or tool – in other words, there are hardly any limits to your research.


Philipp Döring started his doctorate this year in the field of power electronics at the Fraunhofer IAF and the INATECH at the University of Freiburg. He obtained his Bachelor’s degree in Earth Science and his Master’s degree in Sustainable Materials specialized in the fields of Crystalline Materials.

Further employees of Fraunhofer IAF in conversation


Of highly sensitive Satellites and the passion for research


Research management – Getting ideas into the market


»Every piece is a new challenge that requires new ideas and approaches.«


»Creating a relationship built on trust is important for the team spirit.«