Regulating Surface Metal Abundance via Lattice‐Matched Coordination for Versatile and Environmentally‐Viable Sn‐Pb Alloying Perovskite Solar Cells

Narrow-bandgap Sn-Pb alloying perovskites showcased great potential in constructing multiple-junction perovskite solar cells (PSCs) with efficiencies approaching or exceeding the Shockley-Queisser limit. However, the uncontrollable surface metal abundance (Sn