Ligand-Dependent Morphology and Optical Properties of Lead Sulfide Quantum Dot Superlattices

Small angle X-ray scattering, atomic force microscopy, optical microscopy, and absorption and luminescence spectroscopy have shown that the type and amount of surface organic ligands have a strong impact on the morphology and optical properties of 2D superlattices formed by lead sulfide quantum dots (QDs) of different sizes deposited on a glass substrate. This allows control of the process of QD self-assembly, the homogeneity of the superlattices, and the interparticle distance by optimization of the amount of surface ligands. It has been found that annealing and aging also influence the stability of the structural and optical properties of the superlattices.