Nature Materials, Published online: 06 April 2026; doi:10.1038/s41563-026-02546-1The weak contact between the oxide electrode and molecular layer in inverted perovskite solar cells is prone to deformation, limiting long-term device stability. A bulk nano-heterointerface is designed to strengthen the binding force between molecules and spherical silicon oxide nanoparticles, increasing the interfacial contact area and improving the operational stability of perovskite solar cells.