Cost-efficient processes for high-efficiency III-V/Si tandem solar modules with at least 30 % efficiency

An innovative adhesive based on the phenomenon of capillary suspensions discovered at the Institute is to be used to improve the interconnection of sensitive high-efficiency solar cells and make it more efficient.

Capillary suspensions are ternary liquid/liquid/solid systems with two immiscible liquids.

The self-organization of the suspended particles, which is induced by the capillary forces of the second immiscible liquid, drastically lowers the threshold for the formation of a percolating particle network. As a result, the desired electrical conductivity can be achieved with lower silver consumption than with conventional adhesives. The aim of the project is to formulate an electrically conductive adhesive with a conductivity greater than 3000 S/cm and a silver content of less than 40% by weight. In order to achieve this, the potential of halogen-containing additives for increasing the conductivity of silver-containing adhesives is also to be evaluated as part of the capillary suspension concept mentioned above.

The suitability of alternative conductive particles for the production of conductive adhesives is also being evaluated in order to further reduce silver consumption in solar module production.

Finally, a concept for the production of the developed electrically conductive adhesives on an industrial scale is to be developed.