In the present work, ZnO films were obtained on mesoporous silicon substrates by the method of HF magnetron sputtering of a metallic zinc target in reaction oxygen and argon gas medium. The properties of the ZnO films obtained on mesoporous substrates were studied depending on the ratio of the partial pressures of the working gases (argon/oxygen). X-ray analysis showed that in the process of deposition, the ZnO films of a hexagonal structure were formed. The effect of the porous layer on the structural and luminescent properties of the thin ZnO films was studied.The results showed that the porous silicon substrate reduces residual stresses and can be used for obtaining high-quality ZnO films.

No abstract

This work is focused on the creation and study of photosensitive structures based on zinc oxide nanofibers, which are promising for solar energy. Zinc oxide nanowires were obtained on the porous zinc selenide surface. The porous substrate was obtained by electrochemical etching of a low-resistance n-ZnSe plate (110) with a polished surface. Nanowires were deposited by radical-beam epitaxy. The annealing temperature was varied from 400°C to 500°C. The oxygen radical flux was 1.5•10 17 cm -2 s -1 . The process duration was 50 minutes. According to the scanning electron microscopy results, the nanowires length reaches 10 μm, the nanowires diameter is ~1 μm. The predominant X-ray diffraction reflex at 2θ=34.44° indicates the polycrystalline nature of the manufactured ZnO coatings with a wurtzite-type hexagonal lattice. The study of nanowires ZnO luminescence at room temperature contains an ultraviolet peak around 385 nm. This peak is related to the zinc oxide edge luminescence. Based on the fabricated structure, the design of the photoconverter was developed. The upper contact of the fabricated photoelectric converter was created by vacuum thermal sputtering of aluminum through a mask. The deposition was carried out at a substrate temperature of 200° C. Ohmic contacts were made using conductive silver paste. The reverse ohmic contact was formed by applying Al paste to the entire reverse side of the surface. The upper layer of the structure is an array of ZnO nanowires. The active base layer is ZnSe. The light volt-ampere characteristics of the obtained structure were measured in the AM 1.5 illumination mode. No-load voltage Uxx, short-circuit current Isc and the fill factor of the current-voltage characteristic FF of the solar element were measured. The efficiency of the manufactured photoconverter was 13.7 %.

A wide range of possible applications of gallium oxide requires further investigations on growth techniques of its thin films, especially deposited on non-native substrates. One of the ways to avoid imperfection of Ga2O3 film because of variations in structure and lattice parameters of substrate could be an exploitation of buffer porous layer previously synthesized on the substrate. The 170 nm films deposited on porous-Si/Si substrate by rf magnetron sputtering are found out to be composed of β-Ga2O3 elliptical grains with sizes ∼150 nm. Both EDAX and Raman spectroscopy results show formation of a thin interfacial SiO2. Impedance spectroscopy measurements reveals two charge transfer processes with activation energies of 1.33 eV and 1.79 eV.

No abstract