Development of Processes and Measures for Efficiency Improvement and New Materials

Robot for cell string pickup
© Fraunhofer CSP
Robot for cell string pickup.

The Module Technology Center (MTC) in Schkopau manufactures solar modules in all standard and special sizes of up to 2.2m x 2.6m. Equipment comprises an automatic tabber springer (X3 of X-cell automation), an automatic layup (USK), an industrial laminator (Meier Solar Solutions), a xenon flasher (Berger) and an electroluminescence (pi4). The development activities concentrate on the reduction of the electricity generation costs in the module by means of power enhancement (CTM), cost reduction (material), increased throughput rates (processes) or yield increase (process control).


  • Production of solar modules
  • Process development for new materials
  • Development and evaluation of new processes


Robot for cell string layup
© Fraunhofer CSP
Robot for cell string layup.

Manufacture of Solar Modules

In order to reduce electricity generation costs in solar models and increase the module power at the same time, we are working on reducing the optical and electrical losses. To enhance the yield of a module, the development of shading-resistant circuits, the improvement of light coupling and, in general, an increase of the module's service life stand in the focus of our research services.
As far as module manufacturing is concerned, we contribute to the reduction of costs by developing new, cost-saving materials and to an increase in yields by means of an improved process control.

Solar cell soldering
© Fraunhofer CSP
Solar cell soldering in IR soldering unit.

CTM Enhancement

In order to achieve protection against environmental influences and for an easy installation and handling, solar cells are wired and laminated in solar modules. This produces optical and electrical losses which reduce the power of the module. Dividing the solar cells in half reduces the currents in the cells and cell connectors by 50 percent and also reduces the serial resistance losses. This way, and by an intelligent wiring of the half-cells, solar modules with 15W more power could be manufactured. A solar module with 144 half-cells produces 330W, whereas the power of a corresponding reference module composed of 72 whole cells amounts to 315W. This is equivalent to a power increase of nearly 5 percent. The additional power is achieved by reducing the electrical losses and improving the optics within the solar modules. Field measurements of yields carried out over ten months demonstrated that the modules produce three percent more energy. The new development is the result of a one-year project conducted between the Solar Energy Research Institute of Singapore (SERIS) and the Fraunhofer-Center for Silicon Photovoltaics CSP.

One-third Cell Module
© Fraunhofer CSP
One-third Cell Module.

One-third Cell Module

The one-third cell module of the Fraunhofer CSP manufactured at the Module Technology Center (MTC) in Schkopau displays five special features as compared with conventional modules.

The division of the solar cells reduces the electricity per each cell and thus the serial resistance losses in the cell connectors. As the serial resistance losses escalate with the square of the electrical current, the losses can be reduced to one-fourth by dividing the cells in two, and to one-ninth by dividing them into three parts.

soldered connection solar cell
© Fraunhofer CSP
Microscopical cross-section of the soldered connection of a solar cell.

Analysis of Connection Technologies

By applying either destructive or nondestructive test methods we are able to assess and analyze the contact sites according to material scientific and microstructural criteria. Here, experiences acquired from the fields of microelectronics, automotive, power electronics, etc. are supported by our competences in evaluating the contact reliability of the single connection levels in integrated circuit packaging of photovoltaics.

Tabber Stringer
© Fraunhofer CSP
Tabber stringer with induction solder unit.

Cell-String Manufacturing

At the Module Technology Center, we give you the opportunity to manufacture solar modules in small series and test new materials and manufacturing processes.

As we possess a tabber stringer of the latest generation, we can manufacture customized cell strings according to customer specifications (2-4 bus bars, whole cell/half-cell).