NEW NANOSTRUCTURED MATERIAL OBTAINED BY THE METHOD OF TEMPLATE SYNTHESIS

Abstract

The article presents the results of an experimental study of zinc diselenide nanocrystals obtained by chemical deposition, which is the simplest method in the a-SiO2/Si-n track matrix. A sample of the SiO2/Si track was obtained by irradiation with Xe ions with an energy of 200 MeV (F = 108 ions/cm2) on a DC-60 cyclotron (Astana, Kazakhstan) followed by chemical treatment with fluoric acid (HF) in an aqueous solution. Before chemical treatment, ultrasonic cleaning of the sample surface with isopropanol was performed for 15 minutes (6.SB25-12DTS). After treatment, the samples were washed with deionized water (18.2 MOm). The chemical deposition of the track template was carried out at room temperature for 60 minutes. A solution consisting of zinc chloride and Selenium dioxide (ZnCl2 – 3.4 g/l, SeO2 – 0.2 g/l) was used as the electrolyte. The surface of the samples after deposition was examined using a Hitachi S-4800 scanning electron microscope (SEM). Morphological analysis showed that the degree of filling of nanopores varies depending on temperature. X-ray diffraction analysis (XRD) was performed using the D8 ADVANCE ECO X-ray diffractometer. According to X-ray diffraction analysis, the chemical deposition of zinc in the a-SiO2/Si-n trace matrix led to the formation of ZnSe2O5 nanocrystals with an orthorhombic crystal structure. The experimental parameters of the crystal lattice, crystal density, effective charge and chemical bond population are in good agreement with the results of quantum chemical calculations and other literature data performed in the approximation of linear combinations of atomic orbitals. Nonempirical calculations have shown that ZnSe2O5 has a direct range at the G point, and the calculated effective charges of atoms demonstrate a significant covalent contribution to chemical bonds forming mixed ionic covalent bonds. Photoluminescence (PL) was measured by excitation with light with a wavelength of 300 nm in the room temperature. The PL spectra were considered as a symbiosis of luminescence of zinc oxide and zinc selenide. The PL spectrum of chemically deposited samples consists of a wide band in the wavelength range from 2.6 to 3.2 eV at room temperature.