Scalable Ultrasonic Spray-Processing Technique for Manufacturing Large-Area CH₃NH₃PbI₃ Perovskite Solar Cells

Organic-inorganic hybrid perovskite solar cells are on the brink of a breakthrough in photovoltaic technology. Scale-up and large-area processing have become the focal points that must be resolved before commercialization. In this study, the scalable ultrasonic spray deposition method for high-throughput coating of the perovskite photoactive layer with a large active area of up to 3 cm² is implemented by precisely controlling the concentration of the precursor solution and spray passes. CH₃NH₃PbI₃ films with large crystallites and a suitable thickness of ∼350 nm are facilely developed through one-step direct ultrasonic spraying. Less hysteresis and highly reproducible power conversion efficiencies (PCEs) of up to 12.30% (11.43 ± 0.43% on average for 20 devices) are achieved by an optimized single-junction device with an active area of 1 cm², along with good ambient stability. The device retained ∼80 and ∼65% of the initial PCE after 60 and 105 days in ambient, respectively. The ultrasonic spray-coated perovskite solar cells can be further scaled to larger areas of 2 and 3 cm² and exhibit PCEs of 10.18 and 7.01%, respectively. The reliable scale-up process for manufacturing the atmospheric wet-coated perovskite film is available in cost-effective and easily operated bench-top variants to bridge the interconnection between applied research and industry.