Substrate-based galvanic replacement reactions carried out on heteroepitaxially formed silver templates

Galvanic replacement reactions have been widely used to transform solution dispersed silver template structures into intricate nanoshell geometries. Here, we report on the use of these same reactions to form hollow substrate-supported Au–Ag nanoshells from silver templates having a heteroepitaxial relationship with the underlying single crystal substrate. The structures obtained exhibit a nanohut geometry, show highly tunable plasmonic properties and are formed as periodic arrays using a lithography-free technique. When removed from the substrate the inverted nanohuts appear as nanobowls with a notch in the rim. The study lays the groundwork for wafer-based devices utilizing nanoshells located at site-specific locations.