Photovoltaic (PV) solar energy conversion is on the track to become the key technology for a
global sustainable energy supply. A substantial increase of module efficiencies above the
fundamentally and technologically given limit of about 25 % for single-junction PV modules
could disproportionately further reduce the costs of PV electricity. The emergence of the new
material class of metal-halide perovskites and the unprecedented progress in perovskite
solar cells (PSC) over the past very few years provides a unique opportunity to overcome the
single-junction limit with a low-cost approach. The project goal until 2020 is to pass through a first complete development cycle for novel perovskite multi-junction solar cells, this is from the level of material design to modules fully including the system view.