Optical and electrical properties of Au nanoparticles in two-dimensional networks: an effective cluster model

Huimin Su,Kam Sing Wong,Yingshun Li,Xiao-Yuan Li

doi:10.1364/oe.17.022223

Abstract

We report a study of the optical and electric properties of Au nanoparticle networks grown on the porous alumina membrane by dry atom sputtering deposition approach. An effective cluster model was developed to evaluate the dielectric function and the electrical conductivities of the nanoparticle networks by taking into account the effects of the Au particle size, the Au volume fraction, and the particle-particle interaction. The calculated transmission spectra from the model were in good agreement with the experimental data. The percolation threshold of the as-fabricated structure was predicted to occur at Au volume fraction of 0.18, consistent with the dc electric resistance measurement.

Highlights

The interaction of light with metal nanoparticles has been of great interest for both fundamental research and technological applications
We report a study of the optical and electric properties of Au nanoparticle networks grown on the porous alumina membrane by dry atom sputtering deposition approach
With the same effective cluster model, the percolation threshold of the as fabricated nanoparticle networks was predicted to occur at f = 0.18, which agrees with the resistivity measurement

Summary

Introduction

The interaction of light with metal nanoparticles has been of great interest for both fundamental research and technological applications. The as-fabricated nanoparticle networks are modeled as a mixture of the two phases to which the Bruggeman equation is applied This model, which we refer to as “the effective cluster model”, properly accounts for the observed optical and electric responses by including the effects of particle size, particle shape, and the dipole-dipole interaction between neighboring particles. The layout of this article is as follows: In section II, we describe the experimental details regarding the preparation of the Au nanoparticle networks and the characterization by SEM, optical transmission and reflection measurements; Our proposed “effective cluster model” is outlined, where we considered the roleSyntax Error: Unknown font tag 'HeadingPaginationFont'.

Sample fabrication and characterization

Size effect

Aggregation effect

Results and discussion

Conclusions