Cs₂AgBiBr₆ Double Perovskites as Lead-Free Alternatives for Perovskite Solar Cells?

Finding lead-free alternatives remains an important and challenging topic in the field of perovskite solar cells. In this perspective, the potential of Cs2AgBiBr6 double perovskites in solar cells is discussed based on reported absorption and emission data. Whereas the material is capable of exceeding and potentially doubling current efficiency values of around 3%, mainly by an optimized solar cell design, industrially relevant devices cannot be fabricated without major changes in the absorption onset. Nevertheless, Cs2AgBiBr6 poses various scientific questions and exact recombination and charge transport processes are yet to be unraveled, preparing us for the double perovskite or perovskite-like materials to come.