A facile spin-cast route for cation exchange of multilayer perpendicularly-aligned nanorod assemblies for solar cell applications

This master’s thesis outlines the novel spin exchange process which was developed to create centimetre scale nanorod assemblies of copper and silver chalcogenides. These assemblies originated by synthesising CdS and CdSe nanorods and vertically aligning them using electrophoretic deposition or self-assembly. A relatively recent method of exchanging cations within individual nanorods known as cation exchange was applied. This happens at accelerated reaction times of <1s and the strength of the anion sublattice keeps the rod shape intact throughout. Our original approach produces superlattice assemblies in rapid speeds while eliminating toxic cadmium and shows that large assemblies can also remain unharmed. Another unique aspect of spin exchange is the ability to control the depth of the exchange through the layer or layers of nanorods potentially creating a p-n sandwich on a substrate. The resulting assemblies were characterised by TEM, SEM, XRD, EDX and XPS.