Nature-Inspired Redox Shuttle with Regenerable Antioxidant for Efficient All-Perovskite Tandem Solar Cells

• A natural and regenerable redox shuttle using glutathione (GSH) effectively eliminates harmful Sn4+ and Sn0/Pb0 impurities in Pb-Sn perovskite solar cells. • GSH incorporation regulates perovskite crystallization, leading to high-quality charge separation junctions and improved device performance. • GSH-modified Pb-Sn solar cells achieve a champion PCE of 23.71%, and all-perovskite tandem cells reach 28.49% with 90% retention after 560 hours. • This nature-inspired redox shuttling strategy provides a new pathway for developing efficient and stable all-perovskite tandem solar cells.