The solvent-engineering method is becoming an increasingly popular technique to create metal halide perovskite films due to its ability to control microstructure, crystalline structure, phase and orientation. In this technique, crystallization is triggered by applying an “antisolvent in the final stages of deposition. The antisolvent (i.e., a solvent with low solubility for metal and organic halide precursors) removes the host solvent initially used to dissolve precursor materials. Host solvent removal reduces precursor solubility and rapid local supersaturation occurs, initiating nucleation, precipitation, and solidification of the dissolved materials into a uniform film with improved morphology and electronic quality, resulting in better performance and stability of perovskite-based solar cells. The antisolvent-host solvent interaction is frequently discussed based on one-dimensional parameters such as dipole moment, boiling point or permittivity.

However, the predictive capacity of these parameters, such as solubility and molecular interaction, is limited as they provide an incomplete characterization of the molecular interactions. In this work, we propose the implementation of Hansen Solubility Parameters (HSPs) to improve solvents-antisolvents selection. The HSPs offer a sophisticated model to describe interactions based on cohesive energy. HSP is easily applicable to solvents, antisolvents, and mixtures, as well as precursors, and can be visualized in the Hansen space where interactions between the component materials in perovskite formation can be quantified by their distance in the Hansen space. By applying the HSP theory it becomes possible to visualize and quantify the solubility and interaction of solvents an antisolvents involved in halide perovskite film formation.

Following this approach, it is possible to identify suitable solvents and antisolvents depending on their solubility as well as classify them based on their application procedures. Similarly, this approach could aid in the substitution of common hazardous solvents for “greener ones retaining the perovskite film characteristics. The application of solubility models offers a simpler and promising path to enhance perovskite fabrication methods and categorize solvents and antisolvents more effectively.