Preprint Article Version 1 This version is not peer-reviewed

# Investigation of Tunable Surface Plasmon Resonances on Spheroid Core–Shell Alloy Nanoparticles Using DDA Method

Version 1 : Received: 9 July 2018 / Approved: 25 July 2018 / Online: 25 July 2018 (11:53:51 CEST)

How to cite: Liu, J.; Su, C.; Ye, Q.; Chen, W.; Chen, Y.; Yang, C. Investigation of Tunable Surface Plasmon Resonances on Spheroid Core–Shell Alloy Nanoparticles Using DDA Method. Preprints 2018, 2018070480 (doi: 10.20944/preprints201807.0480.v1). Liu, J.; Su, C.; Ye, Q.; Chen, W.; Chen, Y.; Yang, C. Investigation of Tunable Surface Plasmon Resonances on Spheroid Core&ndash;Shell Alloy Nanoparticles Using DDA Method. Preprints 2018, 2018070480 (doi: 10.20944/preprints201807.0480.v1).

## Abstract

In this work, numerical simulations for the absorption and scattering efficiencies of spheroid core–shell nanoparticles (CSNs) were conducted and studied using the discrete-dipole approximation method. The characteristics of surface plasmon resonances (SPR) depend upon shell thickness, the compositions of the core and shell materials, and the aspect ratio of the constructed CSNs. We used different [email protected] compositions, specifically [email protected]2, [email protected]2, [email protected]2, [email protected]2, [email protected], and [email protected], for extinction spectra analysis. We also investigated coupled resonance mode wavelengths by adjusting the composition’s layer thickness and aspect ratio. In this study, we show that the extinction efficiency of the [email protected]2 core–shell nanoparticles (CSNPs) was higher than that of the others, and we examined the impact of TiO2 shell thickness and Ag core radius on SPR peak positions. From the extinction spectra we found that the [email protected]2 nanoparticle had better refractive index sensitivity and figure of merit when the aspect ratio was set to 0.3. All of the experimental results proved that the tunability of these plasmonic resonances was highly dependent on the material used, the layer thickness, and the aspect ratio of the [email protected] CSNPs.

## Subject Areas

surface plasmon resonance; core–shell nanoparticles; discrete-dipole approximation; aspect ratio