Fraunhofer Institute for Solar Energy Systems ISEPero-Si-SCALE offers a scalable process chain for depositing large-format perovskite top cells onto silicon bottom solar cells up to a G12 format size (210 x 210 mm²). We provide equipment manufacturers, solar cell manufacturers, and material suppliers with a platform unique in Europe where equipment, process sequences, and materials can be tested and further developed within a modular laboratory setup. This platform builds on ISE’s in-house expertise in the fabrication of highly efficient perovskite-silicon tandem solar cells in the Pero-Si Lab and simultaneously benefits from years of experience in piloting solar cell processes at the Photovoltaic Technology and Evaluation Center PV-TEC. With the Pero-Si-SCALE laboratory, we support customers in transferring process know-how in the field of perovskite top cells, in selecting suitable equipment for pilot lines, and in manufacturing prototypes in statistically relevant quantities. The goal is to bring industrial products to market readiness faster and to reduce technological and economic risks. Through our close integration with silicon bottom-cell technology from PV-TEC and with module technology at Module-TEC, we offer the unique opportunity to examine perovskite-silicon tandem solar cells across the entire process chain and at a high TRL – from materials to modules. This allows us to leverage potential and minimize risks.
Industrial Evaporation and Sputtering Systems for Perovskite Absorbers and Transport Layers.
© Fraunhofer ISE
Pero-Si-SCALE
Our Services in the »Pero-Si-SCALE« Include:
Evaluation and Development of Scalable Vapor Deposition Processes for Large-Area Tandem Solar Cells
Perovskite solar cells consist of extremely thin (1–1000 nm) functional layer systems. The Pero-Si-SCALE offers precisely tailored thin-film technologies for homogeneous deposition on textured silicon back-contact solar cells. In gas-phase deposition, we use high-rate linear evaporators for the deposition of organic and inorganic contact layers (e.g., C60) as well as for the co-evaporation of perovskite absorbers. Industrial sputtering processes with variable target designs enable the production of thin metal oxides such as NiOx, ITO, or SnO, as well as dielectric layers. In addition, our atomic layer deposition (ALD) system allows for the particularly gentle deposition of buffer layers and ultra-thin passivation layers made from a wide variety of materials. All systems are designed for the G12 wafer format (210 × 210 mm²) and enable pre-industrial evaluation of technologies and materials at a high level of maturity.
Development and Manufacturing of Highly Efficient Tandem Solar Cells up to G12 Wafer Size
A particle-free surface is essential for an efficient perovskite top cell. This is achieved through specialized cleaning processes using ozone, ultrasound, and other oxidizing agents. To this end, we test and evaluate new cleaning agents and systems for their suitability for perovskite-silicon tandem solar cells.
Wet chemical processes offer great potential as cost-effective technologies for depositing contact, passivation, and perovskite absorber layers. To this end, we evaluate various methods such as dip and spray coating, as well as printing technologies like inkjet, rotary, and slot die printing, which are characterized by high scalability. We achieve the final crystallization of the perovskite through a high-precision annealing process that takes place under a controlled atmosphere. In addition, we develop custom coating processes and analyze the raw materials and solvents used in terms of stability, purity, and deposition behavior.
To achieve optimal bonding of the organic hole-conducting molecules to the substrate, we employ UV-, plasma-, and ozone-assisted conditioning. Thin films are deposited using dip-coating or spray-coating processes—methods characterized by high scalability. In addition, we develop custom coating processes and test various organic hole-conducting molecules for stability, purity, and deposition behavior.
We develop and optimize wet chemical processes for the deposition of hole-conducting, monomolecular layers as well as for the application of organic components within the perovskite crystal.
Development and Evaluation of the Complete Process Chain for Tandem Solar Cells on G12 Wafers
At the Pero-Si-SCALE R&D platform at Fraunhofer ISE, we are investigating the complete process chain for perovskite-silicon tandem solar cells on G12-sized wafers. Our goal is to map all relevant process steps in large-area cell production and to gain a precise understanding of their interdependencies. In doing so, we analyze, among other things, what happens between the individual process steps – such as waiting times, environmental conditions, and storage phases – that influence material properties and layer quality. Through targeted process variation, careful data collection during and between processes, and comprehensive characterization, we identify critical interfaces and derive optimization strategies to improve process stability, throughput, and efficiency. In addition to scientific research, we offer our partners and clients the opportunity to evaluate and scale jointly developed processes and transfer them to industry-relevant manufacturing concepts. In this way, we create practical added value for the further development and commercialization of tandem technologies.