Octahedral connectivity reconfigures interfacial carrier-selective properties for efficient perovskite solar cells

Regulation of electron- or hole-selective interfacial properties has traditionally relied on extrinsic chemical doping. Here we report a structurally driven strategy for modulating carrier-selective electronic characteristics through the organic-cation-induced reconfiguration of lead iodide octahedral connectivity. Two closely related imidazoline-based cations, which differ by only a single heteroatom, drive the formation of one-dimensional organic lead triiodide phases with distinct octahedral-sharing patterns. Single-crystal analysis combined with theoretical calculations reveals that the variation in connectivity reshapes orbital coupling, leading to pronounced changes in the work function and absolute band-edge positions that give rise to distinct carrier-selective interfacial behaviour without the introduction of extrinsic dopants. Leveraging this structural reconfiguration-induced electronic modulation, we realize complementary charge-selective contacts in perovskite solar cells, achieving a power conversion efficiency of 27.61% (certified steady-state 27.19%), together with excellent operational stability and scalability, including 22.26% efficiency in 655-cm² modules.