Interview with Prof. Dr. Ralph Gottschalg

The “Photovoltaics” business unit at Fraunhofer IMWS is dedicated to developing reliable, efficient, and sustainable solar cells and modules. Its focus is on optimizing silicon process technologies, module integration, and diagnostic techniques to extend service life. The team enables innovative applications such as the use of sustainable materials, smart PV systems, and digital process optimization.

In your view, what were some of last year’s success stories that illustrate the concrete benefits of your research for customers?

2025 was a very challenging year for the PV industry, and that has also affected our business unit. We responded by bringing Klemens Ilse on board to lead the business unit alongside me starting in October. This allows us to focus more specifically, and with additional resources, on the strategic development necessary to position ourselves well for the changing market conditions.

I’m very pleased with how much recognition we received in 2025 for our expertise. To give two specific examples: The planning tool we developed for the Saxony-Anhalt State Energy Agency received a great deal of public attention. Here, we’re directly supporting the regional energy transition with our expertise. With AESOLAR, we’re developing a module that specifically addresses the challenges of partial shading, thereby promising higher energy yield and greater reliability. This demonstrates how innovative industry partners can benefit from our understanding of materials and technology.

In which areas are you looking for collaboration partners and clients? How do you work with them to create added value?

Our core areas of expertise lie in fault diagnostics and reliability analysis. In addition to characterizing photovoltaic materials, we apply this expertise to a wide range of issues within the energy system, including hydrogen applications and storage solutions. Digital approaches are playing an increasingly important role, particularly in supporting the downstream segment of the photovoltaic market: We have a vast trove of data that we can use, for example, for lifespan and environmental simulations. Of course, our comprehensive, state-of-the-art equipment also sets us apart.

Thanks to this breadth of methodological expertise, we can not only conduct stress tests or performance analyses but also identify the actual failure mechanisms through accompanying high-end measurements and post-mortem analyses. Our clients therefore receive not just measurement data, but in-depth reports from which concrete measures can be derived. This applies to large international companies as well as to startups from the region.

What developments are on the horizon to further expand the business unit’s offerings in the future?

We have established ourselves as a competent partner for material characterization in photovoltaics, and our portfolio for power measurement and yield analysis is also highly regarded. With this, we aim to continue supporting our clients efficiently and flexibly while simultaneously becoming even more capable, for example, in the areas of multiscale diagnostics or the characterization of polymers used in PV applications. In addition, we are exploring new fields where we can make important contributions with our expertise, particularly in the area of quality assurance for the energy transition, as well as increasingly in the hydrogen and energy sectors. The analysis of components and complex system qualification for harsh conditions will also play a greater role in our work going forward.