Organic Solar Cells with Metallogel/LiF Cathode Double Layers and Non-Fullerene Acceptors

Abstract

Metallogels are a new class of soft materials formed by supramolecular interactions between metal ions and low molecular weight gelators(LWMGs), and are well known for their semiconducting nature, especially transition metal-based ones. Recently, it has been shown that some of the metallogels fit into the role of electron transport layers (ETLs) in organic solar cells, offering better performance than that of the conventional ETLs. In line with these results, it is shown here that a Zinc-based metallogel, ZnA- CA (Zinc Acetate Citric Acid), showed better performance as ETL compared to Zinc Oxide (ZnO) in PM6:Y6-based organic solar cells (OSCs). Along with a 5nm thick protective layer of LiF for inhibiting the degradation of the gel/active layer interface, the PM6:Y6 Organic Solar Cell (OSC) returned better power conversion efficiency than that of a cell having ZnO as the ETL.