You work and write your thesis in the field of power electronics. What fascinates you about this subject?
Power electronics is theoretically able to convert energy nearly without losses. This basic concept motivates me to pursue the vision that one day every electric application is powered with maximum efficiency. The unfortunate reality, however, is that to date only few applications, such as solar inverters, use energy converters with an efficiency of over 99 percent. Most of the time, for example in billions of power supply units worldwide, a high transmission loss occurs and energy is wasted. The main reason for this problem is that silicon technology, even though it has been optimized for decades, increasingly reaches its physical limit and is not able to overcome the conflict between efficiency, compactness and cost. We at Fraunhofer IAF want to push these boundaries by researching alternative semiconductor materials that allow us to improve all three aspects at the same time.
What do you currently research, and what is your dissertation about?
In my research, I work with the semiconductor material gallium nitride (GaN) in order to approach the overarching goal of near loss-free electrical conversion. In my dissertation, I go even further by using GaN to increase more than just the efficiency:
I capitalize on the lateral geometry of GaN components via monolithic integration with the aim of realizing numerous functions and sensors, which used to be realized separately, in a single integrated GaN Power Circuit (GaN Power IC). I utilize GaN technology beyond the state of the art, considering that I reach better efficiency and higher compactness at the same time. However, the compactness of GaN ICs in combination with line voltage leads to capacitive coupling effects, a problem that is of no concern in common discrete circuits. My dissertation answers the question of how coupling effects occur and what impact they have on the performance of energy converters. With this new insight, we are able to take interdependency into account during the design of GaN ICs and even capitalize on their effect.
What’s more, these GaN circuits are as inexpensive as current solutions, since economical silicon is used as a carrier material (GaN-on-Si).