Fabrication of metal-semiconductor hybrid clusters for self-organized colloidal devices

Abstract

The aggregates of small number of colloidal particles, colloidal clusters, have been studied from many researchers for understanding of nanoscopic matters as using atomic model and photonic materials. These colloidal clusters provide various possibilities of constructing more complex colloidal structures than can be realized by simple spherical particles. To form compact packing clusters, emulsion templates are used as confined geometry and evaporation of emulsion induce the colloidal clusters that have the unique configuration according to the number of constituent particles. Especially, binary colloidal clusters have selective interactable regions than are uncovered with small colloidal particles. The morphology of the binary colloidal clusters inspires the self-organized colloidal devices. In order to function as a device, colloidal clusters should have active components that can be activated by light, electricity, etc.. We selected semiconductor quantum dots as the active components in self-organized colloidal clusters. Recently, nanometer-sized structures with at least one dimension smaller than the critical size for a given property of a material have attracted considerable attention, mainly due to their size-dependent properties and flexible processing chemistry. Finally, we succeeded to fabricate the self-organized colloidal devices with CdSe semiconductor quantum dots and Au shell particles. Our exploration is expected to bring forward new fields or conceptual paradigm in fabricating nanoscopic devices.