Change in the pathways of polymorphic transitions during colloidal heteroepitaxy

Polymorphic transitions between three hexagonal structures have been observed during the epitaxial growth of colloidal particles when the ratio of particle sizes of the epitaxial and substrate particles was a specific value. These polymorphic transitions were examined by performing Brownian dynamics simulations. In both the experiment and simulations, three types of hexagonal structures formed in the first epitaxial layer when the epitaxial particle size was chosen appropriately. The growth pathways of the epitaxial layers and final structures depend on the growth conditions. The key factors determining the growth pathway and final structure of the epitaxial layers are the interaction between the substrate and first epitaxial layer, the difference in the ease of formation of the second layers due to the unevenness of the first epitaxial layer, and the rate of epitaxial particle supply on the substrate.