Fraunhofer FEP: Anodic arc evaporation coats solar cells
In the EU project Luminosity, the Fraunhofer FEP is testing anodic arc evaporation for the gentle coating of flexible perovskite solar cells. Initial results with tin oxide and caesium iodide show great potential for scalable photovoltaic production through the combination of evaporation and plasma processes.
In the EU-funded Luminosity project, 15 research and industry partners from 9 European countries are working together on fundamental technologies for perovskite solar cells on flexible substrates. Among other things, project partner Fraunhofer FEP is investigating the suitability of the anodic arc evaporation process it has developed for perovskite photovoltaics. This process uses a special electron source (hollow cathode arc discharge) and offers advantages in the targeted adjustment of layer parameters for a variety of materials. The combination of evaporation and plasma processes enables precise adjustment of the layer properties. Previous projects have already shown that anodic arc evaporation can produce high-quality, droplet-free and smooth, extremely hard carbon coatings (ta-C coatings) for hard material coatings. The gentle deposition of transparent, conductive layers for the next generation of silicon heterojunction solar cells was also successfully carried out using anodic arc evaporation.
Until now, the method could only be used for electrically conductive materials. In the Luminosity project, however, the first promising results were achieved for the deposition of tin oxide and caesium iodide. Tin oxide is an important material for the innovative manufacturing technology for flexible solar cells being pursued in the Luminosity project. This requires protective and electrical functional layers that have to be deposited in a gentle manner - without damaging the areas underneath. The evaporation of caesium iodide shows that the deposition of the active perovskite semiconductor layer using this process could also be of great interest in the future. The innovative coating process can be easily scaled in terms of coating width by combining several evaporator modules. The Luminosity project will be presented at the Pro Flex Conference taking place on May 6 and 7, 2025 at the Fraunhofer FEP in Dresden with a presentation by Herbert Lifka from HyET Solar: "Scaling up a Roll to Roll line for flexible PV-modules".