Tin-based perovskites could be used to make stable, eco-friendly solar cells

Researchers from the Helmholtz-Zentrum Berlin (HZB) and the University of Potsdam have investigated ion densities in four common perovskite compounds used for solar cells, discovering that tin-based perovskites produced with an alternative solvent exhibit significantly lower ion density—only one tenth that of lead-based perovskites. This lower ion density correlates with enhanced stability, as mobile halide ions are a primary cause of degradation in perovskite solar cells. The team found that tin perovskites degrade five times slower than lead-based ones, with one tin perovskite variant showing excellent operational stability for over 600 hours. The tin perovskites were synthesized using different solvents, including dimethyl sulfoxide (DMSO) and a DMF-DMI solvent mixture, the latter helping to avoid tin oxidation and reduce ion migration. Lead-based perovskites exhibited the highest ion density, while tin-lead mixtures and tin-only perovskites