Humidity-Insensitive Fabrication of Efficient CsPbI3 Solar Cells in Ambient Air
Recently, CsPbI3 perovskite solar cells (PSCs) have made breakthrough due to constantly refresh power conversion efficiency (PCE) profit from its admirable photoelectric properties and enhanced thermal stability. However, most fabricating processes are operated inside nitrogen glove box in that the CsPbI3 is notorious sensitive to moisture. The tedious and rigorous operation conditions will restrict the CsPbI3 PSCs commercialization. In our research, to solve the awkward situation of fabricating the CsPbI3 PSCs under the ambient moisture, we succeed in attempting an easy one step anti-solvents hot substrate (Anti-hot) spin-coating method to fabricate CsPbI3 film. We expound that pre-heating substrate will accelerate the precursor concentrations up to supersaturation limit with changing the mixed solvents saturated vapor pressure. Meanwhile, the anti-solvents method could induce heterogeneous nucleation. As a result, we could efficaciously control the nucleation generation and grain growth under the ambient moisture and resist the molecular water erosion and damage. Finally, the uniform and compact CsPbI3 film could be achieved and the corresponding PSCs obtain the champion PCE up to 15.91% in high humidity environment (RH, ~50%). We hope our exploration can provide a synthetic approach to help acquire the high-quality CsPbI3 films for PSCs under ambient condition.