Synthesis, passivation and characterization of lead-selenide supercrystals

Abstract

Self-assembly and oriented attachment are used to build complex nanostructured materials. To characterized them, experimental techniques such as Scanning Tunnel Microscopy have to probe their surface, which is currently not feasible due to a layer of organic molecules that coatthe entire volume of these materials. In this work, PbSe supercrystals were synthesized and ligand exchange techniques described in literature were adapted to remove the aformentioned organic layer. This would allow these superstructures to be probed under STM, while keeping the geometry and the electrical properties of these nanomaterials essentially unchanged. Two methods were developed and tested with varying degrees of success. The methodology was also extended to cover different types of nanomaterials, such as nanoplatelets.