SYNTHESIS OF ORTHORHOMBIC TIN DIOXIDE NANOWIRES IN TRACK TEMPLATES

Abstract

In this work, the synthesis of orthorhombic SnO2 nanowires (NWs) was carried out by electrochemical deposition into prepared SiO2/Si-p ion-track template. Track formations in the SiO2/Si structure were created by irradiation on a DC-60 cyclotron with swift heavy Xe ions with an energy of 200 MeV (Ф = 108 cm−2). A 4% aqueous solution of hydrofluoric acid (HF) was used to form nanoporous templates. Electrochemical deposition (ECD) of SnO2 into the track template was carried out at room temperature, the voltage at the electrodes was 1.75 V. During the ECD process, an electrolyte with the following chemical composition was used: 6 g/l SnCl2 (Sigma-Aldrich) – 25 ml H2O – 2 ml HCl (“reagent grade”; 35%; ρ = 1.1740 g/cm3). The surface morphology of the samples, after the ECD process, was studied on a Zeiss Crossbeam 540 two-beam scanning microscope. The phase composition and crystallographic structure of nanoheterostructures (SnO2-NP/SiO2/Si) with nanopores filled with tin dioxide were studied using X-ray diffraction (XRD) on a multifunctional X-ray diffractometer Rigaku SmartLab. Photoluminescence was measured in the optical range of 320–600 nm using a CM2203 spectrofluorimeter (Solar). The electrical characteristics of the synthesized tin dioxide nanowires were studied using a VersaStat 3 potentiostat from Ametek.As a result, a SnO2-NWs/SiO2/Si nanoheterostructure with orthorhombic crystal structure of SnO2 nanowires was obtained. Photoluminescence excited by light with a wavelength of 240 nm has a low intensity, arising mainly due to defects such as oxygen vacancies and interstitial tin or tin with damaged bonds. Measurement of the current-voltage characteristic showed that the SnO2-NP/SiO2/Si nanoheterostructure obtained in this way contains arrays of p-n junctions.