Homogeneity Regulation in Sequential Fabricated Perovskite Film for Industrial‐Scale Deposition of Fully‐Textured Perovskite/Silicon Tandem Cells

The combination of industrially crystalline silicon with metal halide perovskites in a tandem configuration has been the focus of intense research efforts. Although a hybrid deposition method has been developed to achieve conformal and scalable growth of perovskite film on textured silicon, this dry/wet approach faces problems of incomplete reaction and phase impurities, posing a challenge for up-scaling fabrication. Herein, a synergistic strategy is demonstrated for homogeneity regulation of penetration of organic salts by employing solvent engineering in slot-die coating combined with near-infrared (NIR) irradiation pre-heating. The use of mixed solvent contributes to a phase-pure and homogeneous perovskite film by balancing the rate of solvent evaporation and reactant diffusion. Additionally, the NIR energy heats the large-area perovskite wet film directly and rapidly in the air, and thus controls the solvent volatilization for uniform phase transformation. As a result, this strategy enables the air-processed perovskite-silicon tandem device based on an industrial c-Si cell to achieve an efficiency of 30.95% (certified 30.6%) for an active area of 1.0 cm² and obtain an efficiency of 27.1% for an aperture area of 110 cm². Furthermore, the encapsulated large-area device retains 89% of the initial output after 1100 h of maximum power point tracking.