Nature Materials, Published online: 23 February 2026; doi:10.1038/s41563-026-02494-wThe vacuum process is scalable and solvent free, yet all-vacuum-deposited perovskite solar cells still trail solution-processed counterparts. Facet-directed co-evaporation yields (100)-oriented mixed-halide wide-bandgap films for efficient, stable single-junction cells and perovskite–silicon tandem cells.