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.