Colloidal Moderate-Refractive-Index Cu₂O Nanospheres as Visible-Region Nanoantennas with Electromagnetic Resonance and Directional Light-Scattering Properties.

Moderate-refractive-index dielectric nano-spheres are found to possess strong electric and magnetic dipole resonances in the visible region. Owing to the overlap of the electric and magnetic dipole resonances, moderate-refractive-index dielectric nanospheres exhibit directional forward scattering at the strongest scattering peak. Such directional scattering is experimentally observed on colloidal Cu2O nanospheres, which are readily prepared through wet-chemistry methods.