Controlling the Morphology and Interface of the Perovskite Layer for Scalable High-Efficiency Solar Cells Fabricated Using Green Solvents and Blade Coating in an Ambient Environment

Low-cost and solution-processed perovskite solar cells have shown great potential for scaling-up mass production. In comparison with the spin coating process for fabricating devices with small areas, the blade coating process is a facile technique for preparing uniform films with large areas. High-efficiency perovskite solar cells have been reported using blade coating, but they were fabricated using the toxic solvent N,N-dimethylformide (DMF) in nitrogen. In this work, we present highly efficient blade-coated perovskite solar cells prepared using a green solvent mixture of gamma-butyrolactone (GBL) and dimethyl sulfoxide (DMSO) in an ambient environment. By carefully controlling the interface, morphology, and crystallinity of perovskite films through composition variations and additives, a high power conversion efficiency of 17.02% is achieved in air with 42.4% reduction of standard deviation in performance. The findings in this work resolve the issues of scalability and solvent toxicity; thus, the mass production of perovskite solar cells becomes feasible.