Optical Properties of Pure and Alloyed Silver-Copper Nanoparticles Embedded and Coupled in Dielectric Matrixes

Abstract

In this study by using the boundary element method, influence of various parameters on the response to electromagnetic radiation for pure and alloyed silver-copper was investigated. The results demonstrate decreasing interparticle gap from 20nm to 1nm for silver coupled nanoparticles leads to shifting the wavelength of optical extinction peak from 362nm to 393nm. Decreasing interparticle gap from 20nm to 1nm for Cu coupled nanoparticles leads to shifting the wavelength of optical extinction peak from 323nm to 336nm. By an increase in the medium refractive index of 1 to 2 the peak of optical extinction for a coupled Cu nanoparticles with 1nm gap distance the wavelength of plasmon resonance peak shifted from 336nm to 366nm and longitudinal plasmon resonance peak shifted from 498nm to 559nm. By changing the composition of an alloy of copper and silver nanoparticles with diameter of 10nm in dielectric matrix with refractive index 1.3 the wavelength of plasmon resonance peak shifted from 378nm for pure silver nanoparticles to 530nm for pure copper nanoparticles. In addition for Cu-Ag alloy coupled nanoparticles with 1nm interparticle gap, the wavelength of resonance peak shifted from 420nm for pure silver nanoparticles to 544nm for pure copper nanoparticles. In the case of embedded nanoparticles for coupled silver nanoparticles with 6nm gap distance, the wavelength of resonance peak shifted from 396nm to 409nm, and for coupled silver nanoparticles with 2nm gap distance, the wavelength of resonance peak shifted from 414nm to 430nm. Furthermore for coupled Cu nanoparticles with 2nm gap distance, the wavelength of resonance peak shifted from 575nm to 582nm. The results could be employed for plasmatic sensor design and fabrication.