Dynamic Reconstruction of Fluid Interface Manipulated by Fluid Balancing Agent for Scalable Efficient Perovskite Solar Cells.

Laboratory-scale spin-coating techniques are widely employed for fabricating small-size, high-efficiency perovskite solar cells. However, achieving large-area, high-uniformity perovskite films and thus high-efficiency solar cell devices remain challenging due to the complex fluid dynamics and drying behaviors of perovskite precursor solutions during large-area fabrication processes. In this work, a high-quality, pinhole-free, large-area FAPbI perovskite film is successfully obtained via scalable blade-coating technology, assisted by a novel bidirectional Marangoni convection strategy. By incorporating methanol (MeOH) as a fluid balance agent, the direction of Marangoni convection is effectively regulated, mitigating the disordered motion of colloidal precursor particles during the printing process. As a result, champion power conversion efficiencies (PCEs) of 24.45% and 20.32% are achieved for small-area FAPbI devices (0.07 cm) and large-area modules (21 cm), respectively. Notably, under steady illumination, the device reached a stabilized PCE of 24.28%. Furthermore, the unencapsulated device exhibited remarkable operational stability, retaining 92.03% of its initial PCE after 1800 h under ambient conditions (35 ± 5% relative humidity, 30 °C). To demonstrate the universality of this strategy, a blue perovskite light-emitting diode is fabricated, showing an external quantum efficiency (EQE) of 14.78% and an electroluminescence wavelength (EL) of 494 nm. This work provides a significant technique for advancing solution-processed, industrial-scale production of high-quality and stable perovskite films and solar cells.