The obtaining of uniform arrays of silver and gold nanoparticles with a surface density up to 3.3∙109 cm–2 on the zinc oxide buffer layers by sol-gel method is described. The variations of the solution composition and synthesis mode, layers coating and subsequent heat treatment were carried out. The absorption spectra of the obtained samples had a peak near 400–570 nm corresponding to the plasmon resonance in the Ag and Au nanoparticles. Wavelength and shape of Ag and Au nanoparticles plasmon peak varied depending on the synthesis mode: the use of ZnO buffer layers leads to an increase in the intensity of the nanoparticles plasmon peak, the annealing leads to a gradual decrease and broadening of the absorption peak of Ag and mixed Ag and Au nanoparticles arrays, but does not affect the peak of Au nanoparticles.

Micro- and nanoparticles of β-Ga2O3 are synthesized as a result of chemical reaction of an aqueous solution of gallium nitrate and various alkalis: ammonia, sodium, potassium, and lithium hydroxides. It is shown that particles morphology depends on the type and concentration of alkali. The use of microwave treatment of ammonia containing solutions made it possible to change the shape of particles from ellipsoidal to parallelepiped while maintaining their size. In contrast to the synthesis with ammonia, for other alkalis dispersed particles were obtained only at a ratio of alkali to gallium nitrate equal to 3, and these particles did not belong to the gallium oxide β-phase.

β-Ga2O3 thin films were obtained by the sol-gel method on sapphire and quartz substrates, as well as on Cu-O buffer layers. It was shown that the sol-gel method allowed to obtain β-Ga2O3 thin films with good optical and structural properties by using X-ray diffraction, scanning electron microscopy and optical spectroscopy. The energy of the optical band gap of Ga2O3 films calculated by the Tauc plot varied from 4.39 to 4.59 eV.