Our packing models showed that formation of the nanocrystal superstructures is dominated by the selective facet-to-facet contact induced by the anisotropic patchiness of the tetrahedra. Using techniques in real and reciprocal spaces, we successfully characterized the superstructures from their nanocrystal translational orderings down to the atomic-orientation alignments of individual quantum dots.

Here we report the packing of truncated tetrahedral quantum dot nanocrystals into three distinct superstructures-one-dimensional chiral tetrahelices, two-dimensional quasicrystal-approximant superlattices and three-dimensional cluster-based body-centred-cubic single supercrystals-by controlling the assembly conditions. The packing of spherical nanocrystals, which frequently adopt dense, face-centred-cubic or hexagonal-close-packed arrangements at thermodynamic equilibrium, has been much more widely studied than that of non-spherical, polyhedral nanocrystals, despite the fact that the latter have intriguing anisotropic properties resulting from the shapes of the building blocks.sup.11-13. Abstract : The assembly of uniform nanocrystal building blocks into well ordered superstructures is a fundamental strategy for the generation of meso- and macroscale metamaterials with emergent nanoscopic functionalities.sup.1-10.

Nanoshell crystalmaker