• 6 MW excimer line laser for large-area materials and sample processing
• 2-Photon OBIC with spatial sub 10μm signal resolution within an excitation l-range from 400–2,000 nm for space-resolved, high-accuracy photoresponse characterization with automated active focus correction
• Textbook on solar cell measurement technology: »Advanced Characterization Techniques for Thin Film Solar Cells« by D. Abou-Ras, T. Kirchartz and U. Rau, Wiley-VCH (2011)

SILICON NANOPARTICLES FOR PHOTOVOLTAIC (PV) APPLICATIONS
Our objectives are to print n-doped and p-doped silicon nanoparticles as thin films onto foreign substrates (mechanically flexible or rigid) and to use laser processing to improve their electronic properties, making them suitable for use in cost-effective, thin film PV applications. In addition, we are also working on doping crystalline silicon (Si) by laser processing of highly doped Si-nanoparticle thin films for conventional Gen. 1 PV applications. In the process, highly doped Si-nanoparticles are deposited from dispersion and a laser is used to melt and crystallize nanoparticles as well as a substrate near the surface
layer. With its simplified process chain and minimal thermal substrate load, this approach will offer a cost-effective alternative to the conventional doping process.

ORGANIC SOLAR CELLS (OPV)
The low permittivity of organic semiconductor thin films limits the achievable conversion efficiency of organic solar cells by up to 100%. We are working to increase the effective permittivity of organic thin films by integrating electrically isolating, inorganic high-k nanostructures, thus improving the conversion efficiency of organic solar cells by reducing the Coulomb interaction. Anoth­er focus of our research is the characterization, modeling, and understanding of electronic properties and loss processes in organic solar cells. The goal is to identify molecules, process parameters, and component geometries that minimize loss, enabling high efficiency levels at low cost.

• Dr-Ing. Niels Benson (high-k organic photovoltaics, applications of Si-nanoparticles)
• Prof. Dr.-Ing. Thomas Kirchartz (organic photovoltaics)