From pre-fabricated nano building blocks to macroscopic materials: designing exotic electronic phenomena from the bottom up
Dr. Al-Amin Dhirani
Department of Chemistry
University of Toronto
Wednesday, December 11, 2013
C2-361 (Reading Room)
Abstract: Over decades and in many cases even longer, nanostructures have been fashioned with exquisite control over their size, shape and chemical composition. This in turn has led to control over their properties given the strong relationship between structure and property dictated by quantum mechanics at such small scales. If we view nanostructures as “artificial atoms” or “building blocks” to make still larger assemblies of matter, we may realistically hope to fashion a wide range of new materials whose properties at the macroscopic scale can be designed through choice of building blocks and assembly architecture at the nano-scale.
To explore this approach for controlling electronic properties of macroscopic materials, we use a prototype system of two nano-building blocks with contrasting electronic behaviour, namely “conducting” (gold) nanoparticles and nominally “insulating” (alkanedithiol) molecular crosslinkers. A goal of this talk is to provide a survey of the rich range of material electronic behaviours that even just these two building blocks can generate, e.g. single electron effects, metal-insulator transitions, semiconductor transistor-like conductance gating, and a newly observed but theoretically predicted quantum resonance that evolves as the assembly progresses. The latter can be used as a platform to study some remarkable and widely studied quantum phenomena in contemporary condensed matter science. The talk will survey both new insights and new opportunities, including inspiration for commercial technologies, that arise as a result of using nanostructures to assemble materials from the bottom-up.