Au–Cu2O Core–Shell Nanoparticles: A Hybrid Metal-Semiconductor Heteronanostructure with Geometrically Tunable Optical Properties

Abstract

Metal-semiconductor hybrid heteronanostructures may exhibit not only a combination of properties from the disparate components but also further enhanced property tunability and new synergistic properties that arise from the interactions between the metal and semiconductor components. Here we demonstrate that the Au–Cu2O hybrid core–shell nanoparticles not only combine the optical signatures of Cu2O nanoshells and the plasmonic properties of Au nanoparticles but exhibit further enhanced and expanded plasmonic tunability as well due to the dielectric properties of the Cu2O shells surrounding the Au cores. We have developed a robust wet chemistry approach through which we can fine-control several important geometrical parameters of the Au–Cu2O core–shell nanoparticles, such as Cu2O shell thickness, size of the Au core, and the spacing between the core and shell, to systematically and selectively fine-tune the synergistic light absorption and scattering properties of the particles over a broad spectral range ...