Nature Materials, Published online: 03 September 2026; doi:10.1038/s41563-026-02722-3Regulating interfacial properties helps to improve the performance of perovskite solar cells but requires extrinsic chemical doping. A strategy based on an organic-cation-induced reconfiguration of lead iodide octahedral connectivity effectively regulates the carrier-selective interface without extrinsic dopants, achieving efficient and stable solar cells.