Silicon-Based Modules

About

How are individual solar cells turned into a functioning solar module? First, the solar cells must be connected to one another (interconnection); second, the interconnected solar cells must be embedded in protective layers and laminated into a solar module (encapsulation). Our team works on both of these areas.

During interconnection, flat ribbon wires or round wires are applied to the solar cells. This can be done, for example, by soldering. Since the high temperatures involved in soldering are not suitable for silicon heterojunction solar cells or perovskite-silicon tandem solar cells in particular, alternatives such as electrically conductive adhesives are needed that can be applied at lower temperatures or even at room temperature.

The interconnected solar cells are then embedded in polymer layers and laminated into solar modules together with a backsheet on the rear and a frontsheet on the front. In the past, glass sheets were frequently used on the front and back, which resulted in heavy solar modules. Our team is testing various polymer materials as front and backsheets to produce lightweight, flexible solar modules suitable for a wide range of applications.

Research Topics

  • Testing of novel interconnection technologies such as electrically conductive adhesives
  • Investigation of different materials for encapsulating solar modules
  • Adapting interconnection and encapsulation processes to the requirements of perovskite-based solar cells
  • Testing materials for water vapor permeability, Damp Heat Tests
  • Testing materials for resistance to UV light
  • Manufacturing lightweight, flexible solar modules
  • Mounting options for lightweight solar modules
  • Metallization of solar cells with copper instead of silver
  • Development of new recyclable solar module concepts
  • Integration of laser processes for the manufacture of solar modules

Contact

Dr. Andreas Lambertz

IMD-3

Building 02.6 / Room 3017

+49 2461/61-2885

E-Mail

Module Development

Fig. 1 (top) Laminator for SHJ solar module fabrication. (left) Solar modules integrated in a road. (right) Flexible SHJ solar module.

One of the critical processes in PV manufacturing is module lamination. The work in our module team can be divided into two parts. One part is the interconnection of the solar cells. The cells are first interconnected into strings in a variety of ways, from five busbars to multi-wires. Here, the solar cells can be full size, half size or third size. Then the solar cell clusters are assembled with ribbons to produce a PV module. The other part is vacuum lamination, which achieves the longevity of the solar module to withstand different weather conditions. Both crosslinking and thermoplastic polymer encapsulants are evaluated in this process, including EVA, POE and TPO. Various sizes of modules have been encapsulated, from single module to mini module to commercial module sizes with structures such as double glass, glass/back sheet, front/back sheet. Energy conversion efficiencies beyond 23% on active module area of 243.36 cm² are achieved in 2020.

Another topic is the lightweight, flexible module. By eliminating the need for a glass module structure, a significant weight reduction can be achieved while maintaining compatible performance. It expands the variety of applications that are unsuitable for heavy silicon panels and without additional load bears during installation, such as integration of PV on the curved surface of vehicles (VIPV) and of buildings (BIPV), as well as the application of floating PV.

Team members

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Research institutions / facilities

Publications

Key publications

All publications from the group

References

Last Modified: 02.06.2026