The transition from lab–scale breakthroughs to industrial-scale production of perovskite–based tandem photovoltaics demands robust, scalable fabrication strategies. While tandem architectures promise record–breaking efficiencies, their commercial viability hinges on durability as well as fabrication process reliability, uniformity across large areas, and integration into existing manufacturing ecosystems. Solution–based processes dominate at the laboratory scale, benefiting from fast optimization feedback and straightforward integration in modern research environments. Scalable solution-based techniques such as slot-die coating and inkjet printing are widely investigated for their potential in large-area, high–throughput deposition. However, for industrial thin–film manufacturing, vapor-phase deposition processes remain the standard due to their proven reliability and scalability.

This contribution discusses recent innovations in scalable fabrication methods, including slot–die coating, inkjet printing, vapor phase deposition, and digital process monitoring. Recent advances from KIT will be presented that address key challenges in upscaling perovskite tandem solar cells. In the area of printing and coating, we developed a hybrid two-step inkjet printing process that enables precise edge isolation and high–quality perovskite absorber layers for perovskite/silicon tandem devices (Pesch et al.). This method combines material efficiency with spatial control, supporting scalable tandem integration. Additionally, we introduced a spatially regulated gas-flow drying technique for large-area slot die coated films (Geistert et al.), which allows controlled solvent evaporation across the substrate, resulting in improved film uniformity and reproducibility–critical for large-scale manufacturing.

For vapor-phase deposition, we proposed strategies to overcome industrialization bottlenecks. Petry et al. developed a framework for evaluating the throughput of vapor deposition routes, including the arrangement and combination of linear sublimation sources and analysis of precursor thermal stability, aimed at enabling continuous and scalable processing. Diercks et al. present close-space sublimation (CSS) as a vacuum-based, industrially relevant deposition method for the conversion of sublimed PbI2 inorganic scaffolds into high-quality wide-bandgap perovskite absorbers. The latter work was pursues in close collaboration with teh University Valencia. 

Complementing these fabrication efforts, our work on in-situ monitoring and deep learning (Laufer et al.) introduces a predictive process control system that uses sensor data and neural networks to assess film quality in real time. This approach significantly enhances process reliability and yield, offering a pathway toward intelligent manufacturing.

References

Pesch, R. et al. Efficient Perovskite/Silicon Tandem Solar Cells Using Hybrid Two–Step Inkjet Printing with Edge Isolation Precision. Small Sci. 2025, e202500362. https://doi.org/10.1002/smsc.202500362

Geistert, K. et al. Spatially Regulated Gas Flow Control for Batch–Drying of Large Area Slot DieC oated Perovskite Thin Films. Adv. Energy Mater. 2025, 2500923. https://doi.org/10.1002/aenm.202500923

Petry, J. et al. Industrialization of Perovskite Solar Cell Fabrication: Strategies to Achieve High Throughput Vapor Deposition Processes. EES Sol. 2025, 1, 404–418. https://doi.org/10.1039/D5EL00069F

Diercks, A. et al. Close Space Sublimation as A Versatile Deposition Process for Efficient Perovskite Silicon Tandem Solar Cells. A- accepted for publication.

Laufer, F., Götz, M., Paetzold, U. W. Deep Learning for Augmented Process Monitoring of Scalable Perovskite Thin–Film Fabrication. Energy Environ. Sci. 2025, 18, 1767–1782. https://doi.org/10.1039/D4EE03445