Vapor-phase preparation of single-crystalline thin gold microplates using HAuCl4 as the precursor for plasmonic applications

Abstract

We report a facile vapor-phase method to synthesize single-crystalline, atomically smooth gold microplates with thickness less than 100 nm. Compared to the existing methods to synthesize gold plates, the current method uses only chloroauric acid as the precursor and thus allows us to obtain clean gold microplates without any ligands and carbon contamination. By carrying out control experiments, it is hypothesized that Cl⁻ ions play a crucial role in the anisotropic growth of microplates through their selective adsorption on the (111) surface of gold. With their clean, single crystalline and ultrasmooth features, we demonstrate that the synthesized gold microplates may be used to define high-quality plasmonic nanostructures using focused ion beam lithography.