Perovskite films grown with green mixed anti-solvent for highly efficient solar cells with enhanced stability

Organic inorganic hybrid halide perovskite solar cells have attracted considerable attention owing to their high power conversion efficiency. Up to now, anti-solvent assisted one-step spin-coating crystallization method is still a major process to achieve high quality perovskite film. However, the toxicity of commonly used anti-solvents and the nonrepeatability of corresponding solar cell still obstruct the potential of commercial applications. Here, high-quality perovskite film, fabricated with anti-solvent engineering, is successfully developed by using a green mixed anti-solvent of ethylacetate with isopropanol as additive. Compared with pure ethylacetate anti-solvent, the mixed anti-solvent can significantly improve the surface morphology and passivate the grainboundary/surface defects of perovskite film, distinctly enhancing the photovoltaic property and the repeatability of P-i-N planar devices. The best-performing device exhibits a remarkable efficiency of 18.98% with negligible hysteresis and praiseworthy stability over 30 days in dry conditions. Our findings provide an avenue for high efficiency and stable planar perovskite devices with low cost and environmental-friendly manufacturing.