Sub‐10 nm Au–Ag Heterogeneous Plasmonic Nanogaps

Abstract Controlling the formation of bimetallic heterogeneous nanogaps structures have many applications in the plasmonics and catalysis fields. Here, a simple and systematic method is developed to fabricate tunable and stable Au–Ag nanowire‐based plasmonic metamaterials. The sub‐10 nm Au–Ag bimetallic heterogeneous nanogaps with desirable optical properties are fabricated by a simple, ultrarapid, and robust nanoskiving technique. Compared to the monometallic linear Ag–Ag and Au–Au nanogaps, the Au–Ag bimetallic heterogeneous nanogaps exhibit remarkable surface enhanced Raman spectroscopy (SERS) enhancement properties due to the nanogaps between the adjacent Au/Ag nanowires, and the Ag/Au bimetallic composite film. In addition, 3D bimetallic heterogeneous nanogaps are built and produce much stronger electric fields than those of the 1D linear nanogaps. The sub‐10 nm Au–Ag heterogeneous nanogaps are promising to be used in SERS substrate, plasmon devices, catalysis, and printed electronics.