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The possibility for tuned excitation of surface plasmon resonance in Ag-In and Ag-Sb films with different compositions and thicknesses was studied in terms of preparation and microstructural and optical properties. The analyses show that plasmon excitation can be achieved both by changing the thickness of the deposited bimetallic films and by varying their composition. The imaginary ε'' part of the complex permittivity of the thin films has a maximum due to the transverse oscillations of free electrons in the range of 1 eV to 3.5 eV. The films’ applicability as amplifying substrates in surface-enhanced fluorescence was tested. Tryptophan and Cu (II)-phthalocyanine (CuPc) dye were used to analyze the efficiency of the localized surface plasmon resonance excitation in the ultraviolet spectral region. Amplification enhancing coefficient of 4.17 times was obtained in the case of CuPc dye.

The present work reports on the preparation, structural and optical properties of thin bimetallic films from the Ag-In system. Thin films with required compositions were prepared by annealing of Ag/In stacks. The chemical and phase composition, as well as the surface morphology of thin films were analyzed by energy dispersive X-ray microanalysis, X-ray diffraction and atomic force microscopy, respectively. The optical properties of the thin film coatings were characterized by spectroscopic ellipsometry. The increase of the indium content increases the values of the imaginary part of the complex permittivity in the visible spectral region and decreases them in the ultraviolet spectral region. As a result, a shift of the plasmonic activity towards higher photon energies was achieved.

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Thin Au-In films were prepared by thermal co-evaporation and studied by the means of energy dispersive X-ray analysis, X-ray diffraction, scanning electron microscopy and spectroscopic ellipsometry. The alloying tendency in the as-deposited thin films was analysed and the influence of the AuIn2 and Au7In3 compounds on the optical properties and the possibility for excitation of a plasmon resonance in the bimetallic condensates was analysed.