ELLIPSOMETRIC CHARACTERISTICS OF THE OPTICAL CONSTANTS OF ROUGH SILVER SURFACES

Abstract

The highly localized electromagnetic fields in metal nanostructures of various shapes and sizes allows creating unique hybrid photovoltaic converters, optoelectronic devices, optical sensors, and other converters based on plasmon resonance. This paper shows that the technology developed based on electrochemical methods makes it possible to produce rough silver surfaces with deposited polymer films in which surface plasmons with a special spectral distribution can be generated. It describes the processes of transforming electromagnetic radiation incident on rough silver surfaces obtained by the electrochemical method with anodic dissolution (AD) and without AD. This work presents the reflection coefficients s- and p-polarized light which were measured on surface with AD and without AD. The reflection coefficients of polarized light were compared with coefficients of nonpolarised light on different rough silver surfaces. It is also shown that with an increase in surface roughness by 0.15 µm the reflection coefficients decrease by 4 times.

It was established that the conversion of the energy of the p-polarized light into the energy of surface plasmons on the anodically dissolved surface is more effective than on the surface without anodic dissolution. The efficiency of the conversion of incident radiation into the energy of surface plasmons with the due account of the roughness value was calculated. The dispersion curves of the real and imaginary part of dielectric permittivity function were analysed. It was shown that dispersion curves have a complex appearance, which is associated with the roughness of the anodically dissolved surface of silver. The results obtained can be used to develop opto- and biosensors and in photovoltaics for creation of solar energy converters.