Research Project:
During a cation exchange reaction, the cations in a semiconductor nanocrystal are replaced by a different type of cation, while the anion sublattice remains intact. This process has been exploited to synthesize nanocrystal heterostructures and metastable structures – useful in optical and electronic applications – that are inaccessible by conventional synthesis techniques. However, the microscopic mechanisms of cation exchange remain unclear.
I have developed a model to study the microscopic basis of cation exchange, focusing specifically on the effect of lattice mismatch – the difference in size between different types of cations. Lattice mismatch creates effective long-ranged elastic interactions between cations, which results in interesting phase behavior and spatial organization of the cations in the lattice. While at the ESI, I will extend this model to incorporate additional effects, including changes in local bond environments and electrostatic interactions between cations.
Coming soon.