Modification of surface chemistry in quantum dot (QD) thin films through post-deposition ligand exchange is commonly employed to engineer the morphology and electronic landscape of these materials. While much effort has been devoted to analyzing the structures generated following ligand exchange, understanding the dynamics of QD reorganization has been frustrated by a lack of real-time, <i>in situ</i> characterization of structure and ligand chemistry during the exchange process. Digital imaging of QD thin films suspended at a liquid-air interface provides a simple benchtop method for tracking macroscale reorganization of these films during ligand exchange. This presentation will discuss experiments that correlate this macroscale reorganization with changes in nanoscale structure and ligand chemistry. Film reorganization dynamics are found to depend on both the concentration and type of entering ligand. These dynamics are compared across a range of organic and inorganic entering ligands to show how both the binding group and the presence of counterions can affect the reorganization process. Real-time tracking of macroscale reorganization is thereby shown to be a simple technique that provides insight into nanoscale structure and underlying ligand exchange chemistry.

Tracking quantum dot ligand exchange through macroscale thin film reorganization

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.