"The effective conversion of light into chemical or electrical energy is one of the major challenges of humanity during the 21st century. Organic bulk heterojunctions of polymers or aggregates of small molecules combining donor- and acceptor-functionality offer promising prospects for effective light-induced energy conversion. In order to efficiently utilize the solar energy, interpenetrating networks of donor- and acceptor components are often required. While impressive advances have been achieved in organic photovoltaics systems, so far a deterministic control of their nanoscale morphology has been elusive. It would be a major breakthrough to develop model systems with well-defined periodic, interpenetrating networks of electron donor- and acceptor-phases. It is the goal of this project to create such highly defined model systems, to enhance our understanding of the relationship between the electronic and structural parameters and the resulting light-induced charge carrier dynamics. To pursue this challenge, we base our strategy on the recently discovered conceptual paradigm of Covalent Organic Frameworks (COFs). COFs are a class of highly porous, organic crystalline materials that are held together by covalent bonds between molecular building blocks. In a concerted team effort with organic chemists, we will create COFs with different π-stacked heteroaromatic electron donor- and acceptor moieties, thus forming highly ordered interpenetrating networks for light-induced charge separation. This interdisciplinary program is unique as we join the forces of top-level organic synthesis with advanced nanoscience and in-depth physical characterization in one team."