Printable High‐Efficiency and Stable FAPbBr3 Perovskite Solar Cells for Multifunctional Building‐Integrated Photovoltaics

Perovskite solar cells (PSCs) show great promise for next-generation building-integrated photovoltaic (BIPV) applications because of their abundance of raw materials, adjustable transparency, and cost-effective printable processing. Owing to the complex perovskite nucleation and growth control, the fabrication of large-area perovskite films for high-performance printed PSCs is still under active investigation. Herein, the study proposes an intermediate-phase-transition-assisted one-step blade coating for an intrinsic transparent formamidinium lead bromide (FAPbBr₃ ) perovskite film. The intermediate complex optimizes the crystal growth path of FAPbBr₃ , resulting in a large-area, homogeneous, and dense absorber film. A champion efficiency of 10.86% with high open-circuit voltage up to 1.57 V is obtained with a simplified device architecture of glass/FTO/SnO₂ /FAPbBr₃ /carbon. Moreover, the unencapsulated devices maintain 90% of their initial power conversion efficiency after aging at 75 °C for 1000 h in ambient air, and 96% after maximum power point tracking for 500 h. The printed semitransparent PSCs, with average visible light transmittance over 45%, demonstrate high efficiencies for both small devices (8.6%) and 10 × 10 cm² modules (5.55%). Finally, the ability to customize the color, transparency, and thermal insulation properties of FAPbBr₃ PSCs makes them high prospects as multifunctional BIPVs.