Center for Optics and Surface Science

In the “Center for Optics and Surface Science”, we develop optically functional surfaces for numerous applications, using large-area coating and structuring processes.

We apply our coating technology, based on sputtering, to find solutions in the fields of solar thermal energy, photovoltaics, energy-efficient buildings, thin-film batteries and hydrogen technology. The applications include reflectors and absorbers for solar thermal power plants, transparent electrodes and colored cover panes for photovoltaics, low-emissivity and solar-control coatings as well as optically switchable systems for energy-efficient buildings. In addition to optimizing the optical properties, we tailor thin-film stacks to meet the relevant specifications for the final product, e. g. long-term stability in outdoor applications or scalability to industrial production scales. Furthermore, we offer support with system integration of functional stacks of layers, e. g. in a module or a façade. Our spectrum of services comprises feasibility studies, hatch testing and product developments up to complete industrial prototypes.

Structuring surfaces on a micrometer to nanometer scale enables a great variety of optical and non-optical functionality to be achieved. The large-area production of such surface structures in customized forms and dimensions is the basis for industrial implementation. In solar cells, photonic structures result in more efficient light trapping and improved utilization of the solar radiation. In lighting applications, microstructures and nanostructures are used to couple light out of LEDs or direct it into desired directions. In displays, functional structures are used for anti-reflective surfaces, polarization-dependent optical applications or light redirection. Microstructures and nanostructures also play a role in modifying non-optical properties, e. g. by influencing the wettability, adhesion or friction of surfaces.

 

Technical Facilities

State-of-the-art sputtering equipment with a coating area of up to 1,5 x 4 m² with a maximum height difference (pitch) of 16 cm Substrates: flat and curved glass panes, polymer films and metal sheets and pipes Interference lithographic equipment to produce master structures with structure details between100 nm and 100 µm homogeneously over areas of up to 1,2 x 1,2 m² Nano-imprinting and hot-embossing equipment to transfer microstructures and nanostructures onto prototypes Roll-to-plate nano-imprint tool for production-relevant processes Plasma-etching equipment to transfer imprinted structures onto non-polymer materialsn Characterization of the electrical, optical, microstructural and chemical properties of coatings and structures: Fourier spectrometer, film stress measurement, scanning electron microscopy (SEM), atomic force microscopy (AFM), Auger spectrometry, mechanical abrasion tests, electrochemical methods