Kondratenko O. Morphology and optical properties of composite metal and porous dielectric films.

The thesis is devoted to study of interrelation between morphology and effective optical parameters of composite heterosystems with nanosized metallic and dielectric inclusions: gold films with different thickness and morphologies (continuous and island films) on dielectric and semiconductor substrates; composite heterosystems based on semiconductor structures SiO2/Si with developed surface. Classical and topological size effects in thickness dependency of optical parameters of gold films are demonstrated, which are a basic element of nanoplasmonic. The complex analysis of AFM data and calculation of autocorrelation function for surface relief allow determining the shape and size of gold nanoparticles grown on GaAs substrate. The symmetrical Bruggeman effective medium approximation is grounded for description of optical characteristics and adsorption sensitivity of composite heterosystems containing both metallic and dielectric nanosized components. It is shown that thermal annealing of thin gold films on dielectric substrate is an efficient way for influence on structure, surface morphology and optical characteristics that allows controlling the position of peak and half-width of local surface plasmon resonance. It is determined that irradiation of the silicon by high-energy particles causes change its optical constants, increasing of both surface roughness and near-surface defectness of silicon layer. It is shown that creation of developed surface in SiO2/Si structure after irradiation by heavy ions (40Аr, 131Xe, 209Ві) with following etching of pores in layer SiO2 causes increasing of sensitivity of heterosystem effective optical constants to adsorption of ethanol, acetone and ammonia molecules, that points out to perspective for application as gas-sensitive optical sensors.