Interior Structural Tailoring of Cu2O Shell-in-Shell Nanostructures through Multistep Ostwald Ripening

We report a multistep Ostwald ripening approach through which the interior multilayer structures of a Cu2O shell-in-shell nanopartide can be controllably tailored. Using this method, we can fine-control several important geometrical parameters of Cu2O multilayer nanoshells, such as the number of layers, the thickness of each shell, and the intershell spacing, to systematically fine-tune the synergistic optical properties of the particles over a broad spectral range in the visible and near-infrared regions. We have performed Mie scattering theory calculations to interpret the origin of the complex, multipeaked extinction spectral line shapes and geometry-dependent optical tunability of the Cu2O multilayer nanoshells.