Plasma-driven formation of vertically aligned silver-phosphorus core-shell nanostructures

Vertically aligned phosphorus-silver core-shell nanostructures (PSCS) have been successfully grown on silicon substrates using a sequential plasma processing approach. Phosphorus incorporation is achieved through evaporation from a red phosphorus tablet, while the silicon substrate is initially coated with a thin silver layer. The formation of catalyst grains on the substrate surface is essential for nanostructure development. Hydrogen plasma treatment is employed to granulate the silver layer, enabling effective interaction with incoming phosphorus atoms. Subsequent sequential H₂/He plasma treatments initiate and sustain the growth of the core-shell structures. Initial observations indicate that PSCS growth begins with formation of a crystalline silver-phosphorus core, which is subsequently encapsulated by a phosphorus shell, resulting in a core-shell heterostructure. SEM and TEM are extensively used to examine PSCS growth and identify key parameters influencing the process. In addition, XRD and XPS were employed to investigate the crystallinity and surface chemical composition of these structures, respectively.