Structural synergies between conjugated polymers and non-fullerene acceptors: a key to improve photovoltaic stability?

While performances in organic solar cells (OSCs) have soared in the last five years, the lack of stability is hindering the commercialization of flexible, wearables devices. Among the different sources of instability, the diffusion of small molecules out of the mixed domains has been identified as a very important and inherent issue that must be tackled. However, there is still a lack understanding about the structural interaction between rigid conjugated polymers and non-fullerene acceptor molecules, that are nowadays the keystone system for high efficiency OSCs. We have proved in recent experiments how the same system yield different mixing behavior with different thermal stability upon the experimental parameters during fabrication. We aim to study the synergies and structural interactions between a series of conjugated polymers and small molecules, approaching a correlation between the blend and their thermal stability, that will be critical for their performance stability.