AzaBenzannulated perylene diimide multimers as electron acceptors for organic solar cells

We present herein a series of AzaBenzannulated PDI (AzaBPDI) multimers, with their synthesis, characterizations and applications as non-fullerene acceptors in bulk-heterojunction organic solar cells. AzaBPDI dimers and trimer were prepared by a straightforward one-pot sequence of imine condensation, photocyclization and re-aromatization reactions from easily accessible aminoPDI and commercially available di- or trialdehydes, respectively. Their strong visible-light absorption and LUMO energy levels between -3.53 and -3.63 eV make them suitable electron acceptors for organic solar cells. When associated with the donor polymer PM6, we observed high device open-circuit voltages over 1.1 V, thus demonstrating that the AzaBPDI scaffold has the potential for delivering high performance fullerene-free photovoltaics.

Automated summary

In this study, a series of AzaBenzannulated PDI (AzaBPDI) multimers were synthesized and their potential as non-fullerene acceptors in bulk-heterojunction organic solar cells was investigated. The AzaBPDI dimers and trimer were easily prepared through a one-pot sequence of reactions. The AzaBPDI showed strong visible-light absorption and suitable LUMO energy levels, making them promising electron acceptors for organic solar cells. The combination of AzaBPDI with the donor polymer PM6 resulted in high device open-circuit voltages, demonstrating the potential of AzaBPDI for high-performance fullerene-free photovoltaics.