2011-05-05
10:30 at HCI J 574

Assembly of anisotropic nanoparticles for plasmonic and solar energy applications

Asaph Widmer-Cooper

School of Chemistry, University of Sydney

Nanoparticles can now be made in an incredible array of materials, sizes, shapes, and patterns, often with unusual and tunable optical and electronic properties. However, organizing such particles into extended structures that could revolutionize technology remains a challenge. I will discuss two projects that I have worked on in this area. The first concerns the self-assembly of silver nano-polyhedra into mm-sized plasmonic supercrystals, where we have recently discovered and explained the formation of a new packing of octahedra with complex helical motifs (see image); and the second involves directing the assembly of semiconducting nanorods into nano-carpets that can be used for printing solar cells or, when combined with catalysts and embedded in a polymer membrane, for splitting water into hydrogen and oxygen. A key element of this work has been close interaction between experiment and theory in order to understand the interactions that exist between nanoparticles, and between nanoparticles and various interfaces, as well as their phase behavior and non-equilibrium dynamics, and to thereby gain better control over the assembly process.