Charge Transfer from Perovskite Quantum Dots to Multifunctional Ligands with Tethered Molecular Species

TL;DR

This paper develops multifunctional ligands for perovskite quantum dots, enabling efficient charge transfer and stable hybrid materials for optoelectronic and photocatalytic applications.

Contribution

It introduces a ligand design strategy that ensures strong surface binding, colloidal stability, and efficient charge transfer in pQDs, supported by experimental and theoretical analysis.

Findings

Ferrocene-functionalized ligands enable near-unity hole transfer efficiency.

Density functional theory reveals molecular reorganization post-charge transfer.

The approach is extendable to electron and energy transfer processes.

Abstract

Perovskite quantum dots (pQDs) are promising materials for optoelectronic and photocatalytic applications due to their unique optical properties. To enhance charge carrier extraction or injection donor/acceptor molecules can be tethered to the pQD. These molecules must strongly bind to the ionic surfaces of pQDs without compromising colloidal stability. These we achieve by using multifunctional ligands containing a quaternary ammonium binding group for strong pQDs surface attachment, a long tail group for colloidal stability, and a functional group near the pQD surface. Such pQDs with ferrocene-functionalized ligands show fast photoexcited hole transfer with near-unity efficiency. Density functional theory calculations reveal how ferrocene's molecular structure reorganizes following hole transfer, affecting its charge separation efficiency. This approach can also be extended to in photoexcited electron and energy transfer processes with pQDs. Therefore, this strategy offers a blueprint for creating efficient QD-molecular hybrids for applications like photocatalysis.