2D Geometrical Parameters of Asymmetric Plasmonic Crescent-Shaped Nanostructures Fabricated with Colloidal Nanolithography.

A 2D geometric analysis of the thin-film crescent-shaped nanostructure array fabrication process based on colloidal lithography was carried out. Calculation formulas are given that allow, at given angles of evaporation (generally, deposition) of a thin metal film through a mask formed by nanospheres deposited on the substrate surface, and its subsequent sputtering (normal or oblique) through the same mask, to find the 2D boundaries of the resulting crescent-shaped nanostructures. The analytical and numerical results obtained make it possible to optimize the specified angles to obtain an array of the thin-film crescent-shaped nanostructures with the required geometric parameters, such as the crescent tip angles and/or the crescent width. [ABSTRACT FROM AUTHOR]