The central role of colloids to explain the crystallization dynamics of halide perovskites: A critical review

Progress and potentialRecently, there has been a growing interest in seeing the perovskite precursor solution as a colloidal suspension rather than a chemical solution. However, little attention has been paid to how these colloids interact to form perovskite. This review aims to shed light on this aspect, focusing mainly on the effect of additives and solvents on the properties of colloidal suspensions. Colloid theory emerges as a tool for comprehending perovskite crystallization mechanisms, thereby advancing the development of improved perovskite-based solar cells.SummarySolar photovoltaics offers a promising avenue for sustainable power generation, with perovskite solar cells gaining significant interest due to their cost effectiveness and remarkable performance. Lead-based perovskites, while possessing superior electron mobility and carrier properties, raise concerns due to environmental and health risks. Substituting lead with tin holds promise. Tin halide perovskites, particularly with iodine as the halide, exhibit lower band gaps, suggesting heightened efficiency. However, managing the crystallization process, crucial for achieving films with desired morphological properties and crystal phase purity, poses a significant challenge for perovskite materials. Although solvent and additive engineering are extensively explored, their specific effects on the colloidal properties of perovskite suspensions received relatively little attention. This review aims to provide an overview of the world of colloids, shedding light on how the manipulation of colloidal properties in perovskite suspensions can exert a substantial influence on the crystallization kinetics of halide perovskite thin films.Graphical abstract