Study of plasmonic properties of copper monosulfide nanoparticles depending on their dielectric constant

Iryna Yaremchuk,Tetiana Bulavinets

doi:10.15587/2706-5448.2021.237269

Abstract

The object of research is plasmonic properties copper of monosulfide nanoparticles. One of the most problematic areas is that there is still no unambiguous answer to which main copper monosulfide nanoparticles parameters have a decisive effect on their resonance absorption, scattering or electric field enhancement. It is necessary to study the plasmonic properties of copper monosulfide nanoparticles depending on their main parameter, namely the dielectric constant. The principle of dipole equivalence and Mee-Gans theory for the modeling of the optical nanoparticle characteristics is used. It is found that dielectric constant is a crucial parameter determining the resulting optical response of such nanoparticles. The surrounding medium refractive index affects the position and magnitude of the nanoparticles maximum plasmonic absorption. The nonspherical nanoparticles are characterized by two plasmon peaks corresponding to transverse and longitudinal localized surface plasmon resonance if the ratio between the axes is higher than 1.5. The ellipsoidal nanoparticles exhibit higher sensitivity to changes in the refractive index of the surrounding medium in comparison to the spherical ones. The obtained research results are primarily the basis for further comprehensive research of plasmonic copper monosulfide nanoparticles for their specialized applications. Second, knowledge of the influence of the nanoparticle dielectric constant on their resulting spectral characteristics allow tuning of the localized surface plasmon resonance peak position in a wide wavelength range, from 500 to 1200 nm, using the nanoparticle synthesis technique. Thus, the material under study is promising for sensor applications in a wide spectral range.

Highlights

In recent years copper sulfide nanoparticles have at tracted considerable attention in terms of its use in vari ous materials, optoelectronic devices, solar cells, sensors, and biomedicine [1]
It is necessary to study the plasmonic properties of copper monosulfide nanoparticles depending on their main parameter, namely the dielectric constant
In [7] it was shown that the difference between the dielectric constants of four different CuS thin films is quite large: from 10 to 100 for the real part and from 0.25 to 4.0 for the imaginary part depending on the material composition and synthesis technology

Summary

Introduction

In recent years copper sulfide nanoparticles have at tracted considerable attention in terms of its use in vari ous materials, optoelectronic devices, solar cells, sensors, and biomedicine [1]. This interest is primarily caused by low toxicity and high absorption coefficient in the near infrared region [2, 3]. In [7] it was shown that the difference between the dielectric constants of four different CuS thin films is quite large: from 10 to 100 for the real part and from 0.25 to 4.0 for the imaginary part depending on the material composition and synthesis technology. The nanoparticles morphology and the refractive index of the surrounding medium were taking into account

Methods of research

Research results and discussion

Conclusions