The project focuses on investigating and developing novel principles for solar-to-electricity and solar-to-fuel conversion using organic semiconductors and employing multiple photons in a process that mimics natural photosynthesis. The goal is to develop efficient solar energy convertors based on cheap and abundant materials that offer prospects to be employed on large scale and contribute to global conversion and storage of solar energy.Presently, state-of-the-art polymer solar cells reach power conversion efficiencies of ~10% in solar light. Projected efficiencies are as high as 20% when multi-junction solar cells can be employed. Closing this gap is a tremendous challenge that will require pushing every single step in the conversion process to its intrinsic limits, eliminating losses close to perfection. In addition to efficient conversion, storage of energy is crucial because solar electricity supply and demand are intermittent. Capturing solar energy in chemical bonds of molecular fuels is most effective in terms energy density and the first firm ideas are emerging on how this can be achieved. We will use our expertise in the area of polymer solar cells to create multi-junction molecular solar-to-electricity conversion devices with unprecedented power conversion efficiencies and develop new concepts for efficient solar-to-chemical conversion.To reach these ambitious goals, the project focuses on investigating fundamental questions regarding charge generation and on developing new organic materials, electrocatalysts and devices for solar-to-electricity and solar-to-fuel conversion. The activities involve designing and synthesizing new materials, performing photophysical and morphological studies, analyzing charge and exciton transport in relation to morphology, developing new interfacial layers, electrocatalysis, and exploring the use of multi-junction configuration devices in solar cells and artificial leaves.