PrEsto – Perovskite silicon tandem solar cells: Development of scalable process technologies

Perovskite silicon tandem solar cells represent a further development of the established silicon wafer-based standard technology. In this process, a thin-film perovskite solar cell is deposited onto the lit side of an already produced sub-cell. These solar cells, which are both electrically and optically interconnected, convert different portions of the incident sunlight into electrical energy, so that the sum of the electrical energy generated by the individual cells is greater than what could be generated by one sub-cell alone. At the laboratory scale, the current highest published efficiency of these perovskite silicon tandem solar cells is 29.8%, suggesting a high potential for this technology. However, the areas of the laboratory cells are naturally still small (ca. 1cm²) and to date not all of the fabrication methods used in the laboratory meet the challenge of scaling up to industrial production.

In the "Presto" project, various manufacturing processes for the production of perovskite solar cells are being evaluated. In principle, these processes are suitable for large-area coating of silicon solar cells already industrially produced and are scalable for mass production. Together with our partners, we are conducting research into the adjustments that need to be made to material systems and the technical constraints that need to be taken into account for the production of perovskite silicon tandem solar cells.

Important milestones of the project are identification of suitable production processes, demonstration of predicted efficiencies on successively increasing cell areas, and techno-economic evaluations.