Long-Range Charge Transport via Redox Ligands in Quantum Dot Assemblies

We present a strategy to actively engineer long -range charge transport in colloidal quantum dot assemblies by using ligand functionalities that introduce electronic states and provide a path for carrier transfer. This is a shift away from the use of inactive spacers to modulate charge transport through the lowering of the tunneling barrier for interparticle carrier transfer. This is accomplished with the use of electronically coupled redox ligands by which a self-exchange chain reaction takes place and long-range charge transport is enabled across the film. We identified the different modes of charge transport in these quantum dot/redox ligand assemblies, their energetic position and kinetics, and explain how to rationally manipulate them through modulation of the Fermi level and redox ligand coverage.

Automated summary

This article presents a strategy to actively engineer long-range charge transport in colloidal quantum dot assemblies by introducing ligand functionalities. The use of electronically coupled redox ligands enables a self-exchange chain reaction and facilitates long-range charge transport across the film. The different modes of charge transport in these assemblies and their manipulation through modulation of the Fermi level and redox ligand coverage are identified.