Integration of colloidal nanocrystals into lithographically patterned devices

We report a facile method for reproducibly fabricating large-scale device arrays, suitable for nanoelectronics or nanophotonics, that incorporate a controlled number of sub-50-nm-diameter nanocrystals at lithographically defined precise locations on a chip and within a circuit. The interfacial capillary force present during the evaporation of a nanocrystal suspension forms the basis of the assembly mechnism. Our results demonstrate for the first time that macromolecule size particles down to 2-nm diameter and complex nanostructures such as nanotetrapods can be effectively organized by the capillary interaction. This approach integrates the merits of bottom-up solution-processed nanostructures with top-down lithographically prepared devices and has the potential to be scaled up to wafer size for a large number of functional nanoelectronics and nanophotonics applications.