Multi‐Channel Pumped Ultrasonic Spray‐Coating for High‐Throughput and Scalable Mixed Halide Perovskite Solar Cells

Abstract The upscaling of perovskite solar cells to achieve high‐throughput and highly efficient photovoltaic devices is still challenging. In this work, spray deposition of MAPbI 3‐ x Br x mixed halide perovskite is achieved using a ternary channel pumping system to deposit methylammonium iodide, PbI 2 , and PbBr 2 precursor solutions. The compositions of six kinds of perovskite films ( x = 0–0.5) are manipulated by adjusting the flow rate of the syringe pump rather than through traditional methods of preparing and changing the chemical management of the halogen precursors. Large clusters in highly oriented crystalline perovskite films are fabricated as MAPbI 2.91 Br 0.09 film ( x = 0.09) with a champion power conversion efficiency (PCE) of 15.60%. When vacuum‐assisted thermal annealing is used, the optimized PCE increased further up to 17.07%. To confirm the homogeneity of the perovskite film over the large area (7 × 10 cm 2 ), eight divided subcells with dimensions of 2.5 × 2.5 cm 2 showed the highest and average PCE of 17.11% and 16.25 ± 0.77%, respectively. These findings highlight the relevance of high‐throughput screening of perovskite compositions and the versatility of scalable solution process, in which active layers are deposited by spray‐coating.