Ethanol-Assisted Nitrogen-Blade Coating and Surface Passivation for Efficient and Stable Perovskite Solar Modules

Abstract

Scaling perovskite solar cells (PSCs) to large-area modules remains challenging due to efficiency losses from nonuniform films and interfacial defects. Here, we introduce a synergistic strategy combining ethanol-assisted nitrogen-blade coating and iodine (4-fluorophenyl) prop-2-en-1-amine (4-FPPA) surface passivation to fabricate efficient and stable large-area modules. Ethanol incorporation accelerates solvent evaporation during blade coating, enhancing crystallization uniformity and reducing bulk defects. Concurrently, 4-FPPA posttreatment forms a 2D perovskite capping layer by reacting with residual PbI₂, suppressing surface defects and nonradiative recombination. The optimized small-area cells achieve a champion efficiency of 25.11%, while large-area modules (36 cm²) attain a remarkable 22.06% efficiency. Devices fabricated via dual engineering exhibited superior stability against moisture, oxygen and heat. The unencapsulated modules retained nearly 90% of initial PCE after being exposed to air with a relative humidity of 25% for around 1600 h. This work provides a scalable pathway for high-performance perovskite photovoltaics.