Self-assemblies of silver sulfide nanocrystals on various substrates

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. The two substrates used are highly oriented pyrolytic graphite (HOPG) and molybdenum disulfide (MoS2). The self-assemblies of nanocrystals were characterized with scanning electron microscopy and atomic force microscopy techniques, and it was found that the self-organization in 2D and 3D superlattices markedly differs with the substrate used. These changes in behavior are explained in terms of particle-particle and particle-substrate van der Waals interactions and capillary forces.