In recent years, organic solar cells have attracted growing interest from both academia and industry as they provide flexible, large-area devices with up to 13% efficiency that can be produced at room temperature and at low cost. As the efficiency of such technologies is strongly related to the molecular materials used, a connection between macroscopic device properties and molecular characteristics is essential for the design of optimised devices. Here, experiments are often limited in entering the molecular scale. In contrast, simulations of molecular properties and device phenomena can give insights that guide the production of improved organic solar cells.
Within my talk, I will present current activities of our research group in this field using quantum chemical and molecular dynamics simulations at different length scales. Single molecule analysis can efficiently guide synthesis towards improved materials.[K. S. Schellhammer et al. Chem. Mater. 2017] Charge transfer absorption at the donor-acceptor interface is studied in a joint experimental/theoretical investigation providing insight into the distinct behaviour of molecular vibrations at room temperature.[K. Vandewal et al. JACS 2017] And a new nucleation-equilibration algorithm allows systematic construction and analysis of polycrystalline films.