Photovoltaics integrated into façades usually detract from the architectural appearance. The 'Design-PV' project, funded by the German Federal Ministry for Economic Affairs and Climate Protection, is developing aesthetically pleasing solutions that invisibly combine PV-active façade areas with non-active surfaces.
Together with five other partners, the Fraunhofer Institute for Electron Beam and Plasma Technology (FEP) is developing haptic surfaces that are produced using roll-to-roll nano-imprint lithography (RzR-NIL). Another EU-funded project aims to develop innovative processes for improving the performance of perovskite solar cells. One focus here is on optically effective surface structures in order to minimize reflection losses and increase the efficiency of solar cells. Using RzR-NIL technology, the Fraunhofer FEP is working on the cost-effective production of such structures, which are integrated into photovoltaic modules for indoor and outdoor applications in collaboration with 16 partners.
NIL is used to produce surface topographies on films with structure sizes ranging from a few 100 nm to a few µm to the mm range in a roll-to-roll process. This enables large-scale, continuous production of the films. A structured master roll is pressed into a liquid coating layer and the coating is cross-linked at the same time. Cross-linking the lacquer using electron beams allows the structures to be cured quickly and efficiently and offers the option of integrating various pigments or particles into the lacquer. The process is carried out on a web width of up to 1250 mm and a process speed of several 10 m/min.
