Bi-nanorod/Si-nanodot hybrid structure: surface dewetting induced growth and its tunable surface plasmon resonance

Abstract

Hybrid nanostructures composed of plasmonic metal and semiconductor are receiving increasing attentions, owing to their unique optical features that are induced by the co-existence of localized surface plasmon resonance (SPR) and semiconduction as well as the synergistic interactions between these two components. Other than the structures based on conventional noble metals, a cost-effective structure based on non-noble metal is studied in this work. Utilizing the surface dewetting in Bi-Si system, the Bi-nanorod/Si-nanodots hybrid structure (BSHS) is prepared by alternated sputtering of Bi and Si at low rate. The shift, split, and high order excitation of SPRs in BSHS are studied combining numerical and theoretical simulation. Calculations of the optical extinction performed as a function of the size of BSHS show a guideline to tune its spectra.