Nanocomposite and nanomaterials

Optical Properties of Au-CuS Core-Shell Nanoparticles
Bulavinets T.O.1, Yaremchuk I.Y. 1, Volskyi R.R.1, Bobitski Y.V.1,2
1 Department of Electronic Engineering, Lviv Polytechnic National University,
12, S. Bandera Str., Lviv 79013, Ukraine 
E-mail: tetiana.o.bulavinets@lpnu.ua  
2 University of Rzeszow, Pigonia Str.1, 35959 Rzeszow, Poland

Localized surface plasmon resonance, as well as the efficiency of absorption and scattering of radiation is determined mainly by structural and geometric nanoshells parameters. The ratio of the core and the shell size has a significant effect on the nanoshells optical properties with a certain shape. Thus, in this work the Mi theory and the dipole equivalence method are used to analyze the optical properties of spherical and ellipsoidal (prolate and oblate) Au-CuS nanoshells. The combination of the metallic core (gold) ability to localized plasmon resonance [1] and the semiconductor shell (copper monosulfide) [2] provides a high concentration of electromagnetic field on the nanoshells surface and opens new prospects in understanding of plasmonic properties behavior.
This paper studies the nature of changes in extinction spectra when changing the core/shell size ratio in spherical and ellipsoidal (prolate and oblate) Au-CuS nanoshells. The obtained results are analyzed to establish the regularity of changes in the nanoshells extinction spectra, which can be used to develop devices based on them for different application. The plasmon properties of spherical and ellipsoidal Au -CuS nanoparticles with different sizes were determined. It is established that the intensity of the extinction cross section of spherical nanoshells strongly depends on the ratio between the thickness of the core and the shell. Ellipsoidal oblate and prolate core-shell nanoparticles are characterized by two maxima, which corresponds to the plasmon peak of gold and copper monosulfide nanoparticles, respectively. It is possible to configure the plasmon properties of oblate and prolate ellipsoidal core-shell nanoparticles by changing the core and shell thickness in both directions. Thus, the results of the study suggest that Au-CuS nanoparticles can be used as potential elements of various sensitive sensors.

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2.	S. Goel, F. Chen, W. Cai, Synthesis and biomedical applications of copper sulfide nanoparticles: from sensors to theranostics // Small. -2013. -10. P. 631-645.