Congratulations to Isaiah Chen (in Paulette Clancy’s group at JHU) and the rest of the team at Cornell (Jessica, Daniel, and Michelle) for publishing the paper in ACS Nano ‘the role of dimer formation in the nucleation of superlattice transformations and its impact on disorder’
This paper focuses on elucidating the mechanism of the self-assembly of colloidal nanocrystals to form epitaxially connected superstructures, which researchers know needs to be practically perfect to allow coherent charge transport. The community is currently unable to create superlattices with the desired fidelity because we lack an understanding of how nanocrystals assemble and attach to form a bridged superlattice.
This paper sheds light on this mechanism using a molecular-scale computational approach to simulate the assembly process, informed by molecular-scale information from cutting-edge imaging techniques to help both in setting up the initial pre-assembled starting point and validating the computational predictions. Our two key results in this paper are to (i) uncover the significant influence of dimerization during assembly; and (ii) establish precisely and quantifiably exactly how tolerant the (essentially irreversible) attachment of nanoparticles to form a fully connected superlattice will be to positional and rotational disorder in the pre-assembled system. This new definition will assist researchers to find ways to stay within these tolerances as they pursue the goal of perfectly connected superlattices.