Interactions and Energy Scales in Self Assembly and Directed Assembly of Nanocrystal Superlattices

Long range ordered structures of nanocrystals or nanoparticles are known as superlattices. We, and others, have shown that the cohesive energy of nanocrystals in superlattices is very large, of the order of hundrends of $k_BT$. In this talk we will show theoretical and computational results on nanocrystals capped with hydrocarbons showing how these systems overcome these scales and successfully self-assemble into orderes structures with long range order. Irrespectively of the interactions, these systems show a tendency towards local icosahedral order. Time permitting, issues related to polydipersity will be discussed.