MODELING THE FORMATION PROCESSES OF STRUCTURE IN Ag–Au BIMETALLIC NANOCLUSTERS

In the production of SERS substrates, two main approaches are used to form an array of plasmonic nanoparticles: photolithography and chemical methods, each having its advantages and disadvantages. Another possible method is thermal evaporation in vacuum, which was chosen for analysis through computer modeling. For this purpose, molecular dynamic simulation of crystallization processes of binary Ag–Au nanoparticles array was used, allowing smooth adjustment of the plasmon resonance wavelength. Three arrays of Ag–Au nanoparticles with diameter 2.0, 4.0 and 6.0 nm of various target compositions from Ag₉₀Au₁₀ to Ag₅₀Au₅₀ were created and subjected to cooling procedure from melt with different rates of thermal energy removal. During the modeling of Ag–Au nanoparticles internal structure formation, conclusions were drawn about the dependence of these processes on target composition, size, and level of thermal exposure. Based on the obtained patterns, adjustments to the technological process of creating SERS substrates using binary Ag–Au nanoparticles were proposed.