Enhancing luminescence efficiency of CdSe quantum dots through the amine-assisted Z-type ligand

Abstract

The passivation of quantum dots (QDs) by organic ligands is a crucial means to drive the green production and large-scale synthesis of QDs. Alkylamines have been found to significantly enhance the photoluminescence efficiency of CdSe QDs. However, the interaction mechanism between alkylamines and QDs remains unclear. In this study, we propose a type of surface ligand, Z* ligands, formed by the combination of alkylamines with Z-type cadmium carboxylate. Our findings demonstrate that compared to traditional Z-type, L-type, and X-type ligands, the Z* ligand exhibits more pronounced fluorescence enhancement of QDs, while minimizing the surface etching effect. Through density functional theory calculations, we further elucidate the mechanism by which the Z* ligand enhances the photoluminescence efficiency and stabilizes the QD surface. These fundamental findings contribute to a deeper understanding of the passivation mechanism of organic ligands on QDs, and providing new possibilities for the green synthesis of highly luminescent QDs.