Stefano Pisoni1 Thomas Feurer1 Fan Fu1 Shiro Nishiwaki1 Thierry Moser1 Romain Carron1 Stephan Buecheler1 Ayodhya Tiwari1

1, Empa-Swiss Federal Laboratories for Materials Science and Technology, Duebendorf, , Switzerland

Solar cells based on chalcogenide compound semiconductors, such as chalcopyrites, kesterites, and perovskites offer numerous inherent advantages of thin film deposition technologies for potentially low cost production of large area solar modules on flexible foils as well rigid glass substrates. These compounds allow band gap engineering over a wide composition range and they are attractive for development of multi-junction solar cells, especially important is the combination of perovskite as top cell and Cu(In,Ga)Se2 as bottom cell. The talk would provide a review of the developments of all thin film tandem solar cells with a large part covering the progress and the state of the art of high efficiency tandem solar cells and mini-modules on glass and flexible foils in different configurations.