Surface Plasmon Resonance and Field Enhancement of Au/Ag Alloyed Hollow Nanoshells

We investigate the nanostructure, surface plasmon resonance (SPR) absorption and nonlinear enhancement of Au/Ag alloyed hollow nanoshells prepared by the replacement reaction of Ag nanoparticles in a HAuCl₄ aqueous solution. As the volume of HAuCl₄ increases from 0mL to 0.5mL, the SPR band of the Au/Ag alloyed nanoshells is tuned from 430nm to 780nm, andthe third-order nonlinear optical susceptibility is enhanced nearly by an order of magnitude, which indicates a large enhancement of local field in the Au/Ag alloyed hollow nanoshells with hole defects.