Photo-degradation in bulk heterojunction organic solar cells using a fullerene or a non-fullerene derivative electron acceptor

The use of Non-Fullerene Acceptors (NFAs) in the active layer organic solar cells (OSCs) has made it possible to exceed 18% conversion efficiency. However, OSCs still present stability issues under operational conditions that need be surpassed for their industrialization. In this work, we investigated binary and ternary blends examine efficiency as layers OSCs. We used a fluorinated polymer (PF2) an electron donor two different acceptors, fullerene derivative (PC71BM) NFA (EH-IDTBR). demonstrated using EH-IDTBR instead PC71BM leads decrease attributed low out-of-plane mobility measured blend. single electron-acceptor significantly enhanced continuous illumination. Ternary were tested reach simultaneously high long-term stability. best efficiency/stability compromise appeared when only electron-acceptor. identified changes main charge-carrier recombination mechanism photo-degraded devices from bimolecular content trap-assisted ones. Finally, blend morphology at nanometer scale stable while photo-degradation impacted