Optical Conductivity of Spherical Metal Nanoparticles Taking into Account the Size Dependence of the Fermi Energy

Authors A.O. Koval1,2

1Zaporizhzhia Polytechnic National University, 64, Zhukovskogo St., 60063 Zaporizhzhia, Ukraine

2Scientific and Production Complex "Iskra", 84, Mahistralna St., 69071 Zaporizhzhia, Ukraine

Е-mail andrej.koval@ukr.net
Issue Volume 14, Year 2022, Number 2
Dates Received 21 December 2021; revised manuscript received 17 April 2022; published online 29 April 2022
Citation A.O. Koval, J. Nano- Electron. Phys. 14 No 2, 02013 (2022)
DOI https://doi.org/10.21272/jnep.14(2).02013
PACS Number(s) 61.46.Bc, 73.22. – f
Keywords Fermi energy, Metallic nanoparticle, Optical conductivity, Size quantization.

The interaction of electromagnetic waves with a spherical metal nanoparticle is studied in this work. Within the model of a finite spherically symmetric potential well, the dimensional dependence of the Fermi energy of conduction electrons is calculated. It has been shown that taking into account the model of a finite spherical potential well leads to a decrease in the value of the Fermi energy, while the general character of the size dependences is preserved. In the diagonal response approximation, the expressions are obtained and the diagonal components of the optical conductivity tensor of a spherical metal nanoparticle with radius r0 are calculated. The influence of the variation of the effective radius and the material of a spherical nanoparticle on the frequency dependences of the real and imaginary parts of the optical conductivity has been investigated. By comparing the results of calculations of the diagonal component of the optical conductivity tensor of a spherical nanoparticle and a cylindrical nanowire for Cu, the influence of the dimensionality of the systems is established. The results of the calculations show a strong dimensional and frequency dependence of the real and imaginary parts of the optical conductivity. The calculations are performed for Ag, Cu and Al spherical nanoparticles. The differences in the results for Ag, Cu and Al spherical nanoparticles are explained by different values of the relaxation time of conduction electrons.

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