Self-Stimulated Dissociation in Non-Fullerene Organic Bulk-Heterojunction Solar Cells

Non-fullerene bulk-heterojunctions have shown an emerging driving force to realize resistance-free dissociation with energetic order toward developing high-efficiency photovoltaics. Here, by monitoring the dissociation at D:A interfaces with our magnetic field effects of photocurrent, we discovered that the self-stimulated dissociation occurs in the non-fullerene bulk-heterojunction (PM6:Y6) solar cells at the condition that the non-fullerene Y6 molecules are once optically excited to generate a photoinduced dipolar polarization. Here, the self-stimulated dissociation is a unique phenomenon to realize the resistance-free dissociation in non-fullerene organic solar cells, as against other solar cells, which lack self-stimulated dissociation mechanism. Therefore, our work provides much deeper understanding on the operating mechanism of generating photovoltaic actions to further advance non-fullerene bulk-heterojunction solar cells.