The synthesis of monodisperse colloidal semiconductor nanocrystals (NCs) or quantum dots with controlled crystal shape, structure and surface passivation provides ideal building blocks for the assembly of new thin films and devices. These NCs behave like 'artificial atoms' with tunable electronic, optical and thermal properties. This talk will briefly outline our current methods for the synthesis, purification, and integration of single phase NCs and core-shell (heterostructure) NCs and show how these building blocks can be directed to assemble into single component and binary NC superlattices. A and example a binary nanocrystal superlattice (BNSL) of PbS and PbTe nanocrystals is displayed in figure 1.  The modular assembly of semiconductor NCs allows the desirable features of the underlying quantum phenomena to be retained even as the interactions between the NCs allows new delocalized properties to develop. I will focus on the properties that emerge in superlattices as the coupling between the NCs is controlled.  I will share methods we have recently established to direct superlattice formation by interfacial assembly and transfer and demonstrate how pushing to assembly conditions far from equilibrium can drive the process into oscillatory deposition producing films with controlled periodicity on both the nanometer and micron scales.  Specific cases studies in the thermoelectric and optoelectronic properties of IV-VI NC films will be shared as when as the explorations of II-VI NC superlattices for future photovoltaic applications. Progress in the incorporation of and exploitation for plasmonic resonators together with the semiconductor NCs to enahnce the interaction and light harvesting will be shared.

Building with artificial atoms: Multicomponent nanoscale assembly of semiconductor nanocrystal based materials and devices

244th National Meeting (2012)

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