The making of a reconfigurable semiconductor with a soft ionic lattice

Synthetic understanding is crucial for designing halide perovskites with controlled properties and for paving ways to create a new family of structures. With expanding synthetic approaches, it is especially necessary to elucidate the formation of halide perovskites and how that influences their associated properties to inform a unifying design principle. In this perspective, we summarize key milestones in the synthesis community of inorganic halide perovskite nanostructures and highlight how the reaction kinetics and thermodynamics of halide perovskites distinguish them from traditional inorganic semiconductors. We then present a retrospective view that conceptually unites physical chemistry theories with advanced synthesis and address lingering questions in the field along with possible solutions. This perspective aims to articulate the relation between structural properties, synthetic tunability, and the environmental stability of halide perovskites and to provide an outlook for new generations of halide perovskite nanostructures for efficient and stable devices.