Synthesis of ether-bonded perylene diimide oligomers without noble-metal catalysts for organic solar cells

Here, a noble-metal-free synthetic strategy is reported for constructing three perylene diimide (PDI)-based non-fullerene acceptors (NAJ-3, NAJ-2-m, and NAJ-2-p), featuring PDI units linked to one benzene core via ether bonds. Among them, NAJ-3, with a propeller-like conformation, exhibited the best photovoltaic performance. The unique three-dimensional architecture of NAJ-3 enables effective suppression of molecular aggregation while maintaining efficient π-π stacking, which facilitates the formation of nano-sized interpenetrating networks and charge transport. NAJ-3 exhibits the best photovoltaic performance because of the intensified absorption, suitable energy levels, and balanced carrier transport. This work provides a cost-effective synthetic route without noble-metal catalysts for the scalable production of PDI-based NFAs. This is of great significance for the green synthesis of organic photovoltaic materials, yet it has not received sufficient attention.