Optimization of silica-silver-gold layered nanoshell for large near-field enhancement

Abstract

The near-field enhancement of silica-silver-gold (SSG) nanoshells has been investigated by using Mie theory. If the thickness of Au shell is smaller than 5 nm, the maximum of near-field for SSG increases first and then decreases with increasing Ag layer thickness. Thus, the near-field for SSG can be modified by Ag layer and can possess more excellent near-field enhancement. If the thickness of Au shell is larger than 10 nm, the maximum of near-field of SSG nanoshell decreases with increasing Ag layer thickness. We further discuss the influence of Au shell thickness on the near-field of SSG nanoshell. © 2010 American Institute of Physics.