Fraunhofer Center for Silicon Photovoltaics CSPResearch findings from the »IndiFiduell« project attracted considerable attention at the 42nd European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC): the poster presentation by Stephan Großer and the team of authors was honored with one of the prestigious Best Poster Awards. In addition to Stephan Großer, Alexander Müller, Robert Göckeritz, Tobias Nitsche, Daniel Buckland, Giuseppe Galbiati, and Bengt Jäckel are among the authors.
The article, entitled »Investigating the 3-dimensional structure of metallic filler particles in electrically conductive adhesives,« examines the spatial structure of metallic fillers in electrically conductive adhesives for PV applications. The aim is to gain a better understanding of their material behavior and thus enable new, silver-saving connection technologies—an important step toward material-efficient, lead-free PV production.
The research was conducted as part of the »IndiFiduell« project: In this BMWE-funded joint project, an interdisciplinary research team is developing a novel process for connecting silicon solar cells – including n-type back-contact, n-type TopCon, and perovskite-silicon tandem cells – with the aim of enabling long-term stable, high-performance modules.
A central focus is on the efficient use of materials: the consumption of cost-intensive silver for cell metallization and connection is drastically reduced. Instead, a lead-free solar cell connection method is used, which enables individual wire finger contacts and is also compatible with the classic high-throughput string process.
In contrast to conventional solder or conductive adhesive processes, the IndiFiduell process additionally reinforces the mechanical adhesion between the solar cell and the cell connector with an adhesive. This allows electrical and mechanical contact to be optimized separately, which opens up new freedoms in process design and enables significant savings in module manufacturing costs.
The subproject at Fraunhofer CSP is dedicated to the evaluation and characterization of resource-saving, lead-free electrical contacts for photovoltaics. The focus is on determining material-property relationships in order to specifically improve the performance and sustainability of future module technologies.
In addition to established measurement methods related to process development, Fraunhofer CSP is also focusing on the development and testing of new microstructural analysis methods to precisely evaluate the contact quality of solar cells. The aim is to specifically reduce the use of expensive materials such as silver – without compromising electrical performance or stability – and thus develop resource-saving connection technologies for photovoltaics.
The award at EUPVSEC 2025 underscores not only the scientific quality of the work, but also the relevance of the topic for the international photovoltaic industry.
»IndiFiduell« is funded as part of the 7th Energy Research Program of the Federal Ministry for Economic Affairs and Energy (BMWE) (FKZ 03EE1185).
(October 7, 2025)