Crystallographically Oriented Hybrid Perovskites via Thermal Vacuum Codeposition

Hybrid lead halide perovskites typically form polycrystalline films that have multiple grain sizes and surface defects. A key engineering challenge toward commercialization is therefore the production of homogeneous, defect‐free large‐area devices achieving high efficiency. New market opportunities may arise from vacuum‐deposited if detailed understanding control crystal formation are available. Of many factors make reproducibility device performance difficult, two variables identified not yet been considered in detail: deposition speed underlayer material selection. Herein, it demonstrated small changes perovskite growth rate (0.18–0.72 Å·s −1 ) substantially affect preferred orientation. Further, varying interfaces greatly influence composition final thus its energetic profile. The research aids fine‐tuning film at nanometer scale, which enables reproducible fabrication vertically aligned micrometer‐sized features, highly demanded for high‐quality semiconductors.