Just Scratching the Surface: <i>In Situ</i> and Surface-Specific Characterization of Perovskite Nanocrystal Growth
James C. Sadighian, C. Wong
Abstract
The model of nucleation and growth proposed by LaMer has guided our understanding of nanocrystal (NC) formation for over 70 years. However, LaMer’s model does not account for the effects of surface–ligand interactions on the availability of precursor, the resulting burst nucleation, or the growth of the NC. These interactions play a critical role in determining the electronic properties and physical structure of perovskite NCs. The surfaces of perovskite NCs are dynamic, with multiple processes occurring simultaneously, such as the adsorption and desorption of ligands and growth via incorporation of precursor or oriented attachment of small crystallites. These unstable surfaces are difficult to characterize during growth. A model of NC growth that includes the behavior and impact of ligands at the NC surface would enhance rational syntheses of perovskite nanomaterials with targeted properties. Here we discuss techniques and strategies that have provided insight into the nature of NC surfaces, emphasizing the need for new, multimodal, in situ measurements to characterize the role of surface ligands during perovskite NC growth.