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• The perovskite film was prepared by ultrasonic spraying method. • Isopropyl alcohol (IPA), a green solvent with low boiling point, was introduced into perovskite precursor solution. • IPA-based PSCs exhibit the champion device efficiency of 22.43 %. The ultrasonic spray coating has been shown to be an effective technique for scaling up production. The nucleation and crystallization process of the perovskite film prepared by the ultrasonic spraying approach is more complicated than that by the spin coating, but they are essential to gaining efficient perovskite solar cells (PSCs). At the same time, the green solvent is the primary problem that must be solved in the process of PSCs commercialization. In this paper, the low boiling point and green solvent isopropyl alcohol (IPA) is introduced into the perovskite precursor solution to prepare FAPbI 3 perovskite by ultrasonic spraying. The addition of IPA enhanced the saturated vapor pressure of the precursor solution, which can create the local chemical microenvironment on the film surface and subsequently retard the nucleation rate from 8.31 s to 8.54 s at nucleation stage. The local chemical improves the initial homogeneity of the sol–gel phase and then leads to improved structural and optoelectronic properties within the FAPbI 3 film via sufficient crystallization from the sol–gel phase to α-FAPbI 3. Ultimately, IPA-based PSCs exhibit the champion device efficiency of 22.43 %. The good long-term stability of PSCs (maintain more than 90 % of the initial efficiency after 1000 h, and keep 80 % after 400 h) in ambient conditions. [ABSTRACT FROM AUTHOR]

Highlights: [•] Self-assembly of recombinant rotavirus virus-like particles. [•] Post-purification assembly yields homogeneous particle. [•] Virion-like epitopes on virus-like particles by on antibody binding analysis. [•] Improved stability, antigenicity and protective efficacy of double-layered VP2/6 VLPs. [•] Resemblance of Escherichia coli-derived VLPs to virus-derived double-layered particles. [Copyright &y& Elsevier]