The expertise of the Fraunhofer Energy Alliance runs along the entire value chain of silicon photovoltaics. It spans the entire range from the crystallization, wafering and cell production through to the interconnection of modules. Experts at Fraunhofer develop optimized overall system designs and are leading in the inverter technology. For concentrating PV systems, highly efficient III-V multi-junction solar cells and optical systems are developed to bundle the sunlight. The portfolio also includes silicon thin-film cells and the usage of alternative material systems. In the up-and-coming sector of organic solar cells and dye-sensitized cells, research is conducted on the improvement of efficiency and long-term stability.

Competences »Photovoltaics« | Fraunhofer Energy Alliance

PV Production Technology

The member institutes of the Fraunhofer Energy Alliance are researching innovative production technologies for solar cells to use solar energy more effectively. On the one hand, standard processes for the production of solar cells are being further developed. On the other hand, new technological concepts are systematically transferred from laboratory research to industrial application. To this end, we evaluate and develop manufacturing processes and process technology components, manufacture advanced industrial solar cell structures and characterize and optimize materials and solar cells. Aspects such as digitalization, recycling and sustainable production are important components of our concepts.




ASYS Solar and the Fraunhofer Institute for Solar Energy Systems (ISE) evaluate and develop suitable system processes for the cost-effective metallization of Si solar cells.



»CUT-B« investigates material and process related causes for fluctuations in the efficiency of multi-crystalline silicon solar cells with passivated emitter and rear.

Silicon Photovoltaics

Silicon is currently the most widely used semiconductor material for manufacturing solar cells. The keys to this dominant market position are, on the one hand, a robust and cost-effective manufacturing process and, on the other, the high efficiency and high reliability of silicon-based PV modules. Efficiency in particular plays a decisive role in further reducing electricity generation costs and is therefore the focus of research activities. The member institutes of the Fraunhofer Energy Alliance support the research and development of material, module and system manufacturers from silicon material to solar cell and module to system. The technological maturity of our projects covers the entire range from laboratory research to industry-oriented development. With new technologies and world record efficiencies from our research laboratories, we repeatedly set scientific trends in photovoltaics and thus provide important impulses for new developments.




At our branch office in Halle/Salle, the Fraunhofer Center for Silicon Photovoltaics CSP, different separation processes, cleaning processes, and melting and crystallization technologies are used and advanced to offer scalable, cost-effective recycling processes.



Cost-Optimized High-Efficiency Solar Cells of Low-Oxygen N-Type Monocrystalline Silicon for Industrial Mass Production.



A simple silicon solar cell can only reach a limited efficiency. III-V multi-junction solar cells, however, have already demonstrated that almost twice as much electricity can be generated on an area of the same size.

Thin-Film Photovoltaics

Compared to solar cells made of crystalline silicon, thin-film solar modules are used less frequently, but have advantages in certain applications. For example, they cope better with shading and deliver higher yields in low light conditions. The energy and material consumption in the production of thin-film photovoltaic modules is also significantly lower. Researchers at Fraunhofer are working on exploiting the potential of thin-film modules by using other materials and optimizing production on an industrial scale.



Thin-Film Solar Modules

The joint project of the Fraunhofer CSP and Calyxo GmbH explores the potential fo thin-film solar modules based on cadmium telluride (CdTe) to make it usable for production on an industrial scale.

Concentrator Photovoltaics

In areas with a lot of direct solar radiation, the use of concentrator photovoltaics (CPV) is a cost-effective technology. Very high efficiencies are achieved by concentrating sunlight through lenses on highly efficient multi-junction solar cells. Fraunhofer covers all aspects from the solar cell to the module and optimizes the entire system. Expertise in the areas of optics, assembly and joining technology as well as theoretical modeling and module design is used for this purpose. Thus, a heterogeneous market of companies developing PV systems with low to very high optical concentration can be supported. The portfolio also includes the evaluation of specific requirements for the use of concentrator photovoltaics on site within and outside Europe.




In the ALCHEMI project, a HCPV module is to be developed within a European consortium with central components (primary optics, cell) potentially being provided by German suppliers.



The focus of the CPVMod research project is the development of innovative, high-performance concentrator photovoltaics (CPV) module as they can concentrate sunlight onto highly efficient solar cells that are only a few square millimeters in size.



The main objective of the project is the installation and scientific evaluation of a 53kW CPV system for power generation in India. In addition to the CPV system, an outdoor measurement stand was installed for the electrical characterization of (C)PV modules.

Organic and Perovskite Solar Cells

Organic and perovskite solar cells offer promising possibilities to produce solar cells from low-cost materials. Researchers of the Fraunhofer Energy Alliance are working on developing novel materials to increase the efficiency of these solar cells, improve long-term stability and reduce production costs. In outdoor test fields for photovoltaic systems, individual modules and complete systems can be tested for this purpose over longer periods of time. In addition to pure perovskite solar cells, we are developing silicon-based multi-junction solar cells to make better use of the solar spectrum by reducing thermalization losses.




The objective of the “PersiST” project is the production of a perovskite silicon tandem solar cells with an efficiency of more than 29 %. Perovskite solar cells can use high-energy blue and green light significantly more efficiently than silicon solar cells.



Approx. 20 million m² glass surfaces are installed in Europe every year for building facades. The Fraunhofer ISE wants to use these facades more efficiently with the help of dimensionable solar foils.  



In the »PeroTec« Fraunhofer project, the technological prerequisites for applications in the square meter range should be established and patent-protected for the industrial use of novel perovskite materials.

Inverter for PV Systems

Inverters are important for solar power generation as they play a major role in determining the efficiency and reliability of PV systems. Inverters convert the direct current generated by solar cells into alternating current and optimize, for example, the feed into the power grid. In research on PV inverters, our member institutes focus not only on optimizing efficiency and reliability, but also on the aspect of cost optimization. The research of the Fraunhofer Energy Alliance is advancing both hardware and software development. New requirements of the electricity system (such as own consumption, grid services and storage integration) determine the further development of inverters.




The aim of the joint project is to investigate the potential faults of photovoltaic inverters as it is very important that the quality and reliability of the devices are ensured in terms of their longevity and continuous operation (24/7).


UPS Inverter with SiC Transistors

A highly compact inverter has been developed at Fraunhofer ISE for an uninterrupted power supply (UPS) with an efficiency of up to 98.7 %.


»PV Power Plant of the Future«

In this project, a power plant concept is developed in combination with storage units that allows the increase of the PV energy portion to values above 90 %.