Halogen-free Solvents for Non-Fullerene Organic Solar Cells

Organic solar cells are an exciting, clean energy generating technology offering low-cost, scalable fabrication routes. New non-fullerene acceptors such as ITIC produce highly efficient devices but they are typically achieved using halogenated solvents which are harmful to human health and the environment. Using environmentally friendly, halogen-free solvents such as o-xylene and CS2:acetone not only mitigates these problems but also increases the ease of scalability and industrialisation. In Sheffield, we have produced halogen-free devices with efficiencies comparable to halogenated systems. Using SANS, we will probe the bulk morphology of a range of halogen-free blend thin-films. These results, combined with other characterisation techniques will allow us to develop a thorough understanding of the structure-property-function relationships which is key to improving device performance.