Growth of Co9S8 Islands on Cu2S Nanodisks

Nanosized heterojunctions enable the study of physical processes such as charge transfer and also present a substrate to realize low-dimensionality devices. Here, we describe the formation of pristine heterojunctions between Cu2S and Co9S8. We observed heterojunction formation in a single reaction. Heteroassembly occurs due to the Cu2S nanodisk (ND)-assisted nucleation of Co9S8 nanocrystals (NCs). Evidence for this mechanism comes from the observation of epitaxy between the two materials. Heteroassemblies exhibit emergent physical properties that are absent in the two independent phases.