Local surface plasmon resonances in Cu/As$_2$Se$_3$ film structures

Plasmon nanostructures are synthesized for the first time as a result of Cu diffusion into an As$_2$Se$_3$ film during the formation of a Cu/As Se film structure by the successive deposition of Cu and As$_2$Se$_3$ in vacuum. Using spectroscopic ellipsometry, the spectra of the extinction coefficients and refractive index, as well as the real and imaginary parts of the permittivity of the synthesized structures in the wavelength range of 240–2500 nm, that indicate the presence of localized surface plasmon resonances are obtained. It is shown that the frequency position of plasmon resonances in the wavelength range from 470 to 660 nm can be controlled by changing the thickness of the copper film and annealing.