Design of generic assays based on electron paramagnetic resonance to understand degradation processes in novel fullerene-free organic solar cells.

The constantly increasing global energy demand and massive use of fossil fuels is putting a very heavy burden on our environment. Not surprisingly, policy makers world-wide are pressing for renewable and eco-friendly alternative energy sources. Solar energy is inexhaustible and offers many possibilities. In principle, organic solar cells (OSCs) would be ideal, since they are light, flexible, and offer the potential of large-area fabrication. Their cost can be kept low, provided nonfullerene OSCs with sufficient power conversion efficiencies can be found. The recent successes in synthesis of materials for non-fullerene OSCs are very promising. However, one of the biggest problems common to all OSCs is the poor stability of the cells. Advancements in OSC stability can only be obtained through in-depth knowledge of the molecular reaction paths and morphological changes that impair this stability. This in turn requires good assays to monitor and evaluate these processes. This project targets at the development of a systematic methodology, based on different electron paramagnetic resonance techniques, to study mechanistic steps in OSC degradation on a molecular level. The assays will be optimized for studies of both the organic core materials (blends) and the corresponding OSC devices. The methodology will be applied here to the case of non-fullerene OSCs, but will be generic for studies of other OSCs and related novel photovoltaic devices.

Keywords:ELECTRON SPIN RESONANCE, SOLAR CELL

Disciplines:Classical physics, Elementary particle and high energy physics, Other physical sciences