Influence of the substrate on the self-assemblies of silver sulfide nanocrystals

The influence of the substrate on the morphology of 2D and 3D superlattices made of 5.8 nm silver sulfide nanocrystals coated with dodecanethiol is reported. Two substrates, highly oriented pyrolytic graphite (HOPG) and molybdenum disulfide (MoS2), are used. Self-assemblies of nanocrystals are characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM) techniques. It is proposed that the different behaviors observed on the two substrates are related to van der Waals interactions between particles and between particle–substrate as well as to capillary forces.