Fig. 1

a Schematic of the classical free energy diagram for homogeneous nucleation as a function of the particle radius. Reproduced with permission from Ref. [33]. Copyright 2019, The Royal Society of Chemistry. b LaMer model for nucleation and crystal growth. Regions I, II, and III represent prenucleation, nucleation, and growth stages, respectively. c Nucleation (red trace) and growth (blue trace) rates as a function of the supersaturation degree. Reproduced with permission from Ref. [34]. Copyright 2017, Springer nature. Preparation methods of PVK SCs are categorized as d temperature cooling crystallization, e slow evaporation crystallization, f inversion temperature crystallization, and g antisolvent vapor-assisted crystallization