Center for Emerging PV Technologies

In the »Center for Emerging PV Technologies«, we are working on the next-generation solar cell technologies, placing particular emphasis on organic and perovskite solar cells. Both technologies have in common that the materials used can be applied from solution at low temperatures by coating and printing processes. This makes production on roll-to-roll equipment possible, thus opening up enormous potential for large production volumes and low manufacturing costs.

Organic solar cells do not require the use of toxic substances such as heavy metals and can achieve very good life cycle assessments, due to their extremely low material and energy consumption during manufacture. In addition, their manufacture is RoHS-compliant (Restriction of certain Hazardous Substances) as set down by the EU. Due to their special absorption properties, organic solar cells are particularly suitable for transparent solar cells, as they offer high imaging quality and adaptable spectral absorption. Some examples of applications are solar active windows in buildings and vehicles or protective films in agriculture.

In the field of perovskite solar cells, remarkable progress has been made in recent years. The efficiency is steadily increasing, so that high efficiencies of over 25% have already been achieved for small laboratory cells. Perovskite solar cells are also used as top cells in tandem solar cell structures together with a bottom cell made from the established crystalline silicon technology. This promising perovskite-silicon solar cell enables a further quantum leap in efficiency, compared to the conventional pure silicon cell technology, which is dominant today. Also, a tandem solar cell that combines two perovskite absorbers with different band gaps shows great potential for increasing efficiency and reducing costs.


Services and Expertise

Evaluation of Materials and Components

We have laboratory lines for processing under inert gas. Currently, three glovebox lines with spin coaters, vacuum evaporators and various automated basic characterization processes are in operation. Solar cells are produced on these lines under exclusion of oxygen and water in order to test and optimize new materials and layer stacks.

Characterization and Modeling

To identify the factors limiting the efficiency of solar cells and modules, various electro-optical characterization techniques are used. In addition to current-voltage characteristics at various intensities and temperatures, these include electro- and photoluminescence measurements (both steady-state and transient), LBIC (Light Beam Induced Current), and DLIT (Dark Lock-in Thermography). Imaging techniques can also be used for these methods. Numerical simulations of the various processes occurring in the solar cells allow us to further our understanding.

Upscaling and Manufacturing in Roll-to-Roll Processes

Fraunhofer ISE develops layer systems, PV module concepts and production processes which are suitable for cost-effective roll-to-roll production. Even for medium production volumes, material costs are the largest factor in roll-to-roll production costs. Thus, our major focus here is to develop manufacturing solutions that are cost-effective, available and compatible with safety requirements. Upscaling can be carried out at various development stages, from spin-coated laboratory modules up to demonstrators produced on sheet coating and flatbed screen printing systems and large PV modules produced on film rolls with the roll-to-roll process.     

Technical Equipment

With our inert atmosphere through the preparation phase and partially automated characterization line, we are able to both perform and evaluate extensive parameter variations in a short amount of time.

Dust-reduced room for substrate cleaning (UV-OZON, ultrasonic bath) and spin coating under laminar flow

Three connected gloveboxes for fully inert production and semi-automated characterization of components, from the mixing of solutions through the spin coating of organic functional layers up to the vacuum coating of metals and oxides (characteristics under dark, bright (AM 1.5G) and artificial light, spectral sensitivity measurements)

Two additional gloveboxes, one for coatings (spin coater, blade coater) and one for computer-controlled vacuum coating (four thermal sources, electron beam with automatically changing crucibles)


We manufacture organic and perovskite solar cells and modules both on single substrates and in roll-to-roll processes. The following equipment is available for this purpose:

Film applicator with adjustable squeegee, temperature-controlled base plate and air knife for defined drying (operation possible under inert gas and in air).

Coatema Easycoater for slot dye coating on single substrates (operation with nitrogen and air possible)

Glovebox-integrated, automated slot dye coating system for the production of solar cells and modules on single substrates (up to 30x50 cm²) under an inert atmosphere

Kroenert "LabCo" roll-to-roll coating machine, working width 500mm

Slot dye casting (inert gas or air) (TSE Troller, Switzerland, AAA grade, 250mm)

Rotary screen printing (SPG print Storck RSI compact, 330 mm)

R2R Flexodruckwerk (500mm, Norbert Schläfli Maschinen, Schweiz)

Circulating air/float dryer (inert gas or air) (Kroenert BMB Drytec) for printing and coating processes (up to 150°C, 2 m long)

Laminating unit (inert gas or air) with register control

proprietary thread wiping process for structuring (air)

UV curing for bonding the modules after separation

Access to precision printing processes from silicon technology


Simulation and characterization of customer components: A wide range of tools are used from electro-optical component simulation to imaging characterization, for example.

Electrical simulation of components (Sentaurus TCAD)

Optical simulation (transfer matrix, RCWA, etc.)

Simulation tools for module and cell layout optimization

Suns-VOC for optimization and monitoring (steady state and quasi-steady state)

Spectroscopy measurements (UV-VIS, photo- and electroluminescence)

Imaging characterization method (thermography, photo- and electroluminescence)

Electro-optical characterization (CELIV, VOC and JSC, etc.)