Enhanced optical transparency and electrical conductivity of Ba and Sb co-doped SnO2 thin films

The highly conducting Ba and Sb co-doped SnO2 (BATO) thin films have been deposited on the glass substrates by cost-effective spray pyrolysis method. The structural, surface, optical properties of the films are investigated as a function of fixed Sb and varying Ba doping concentrations. X-ray diffraction data indicated the films to be polycrystalline with a tetragonal crystal structure. The 2 wt % Ba and 5 wt % Sb co-doped (BATO(2)) film showed higher average transmittance of about 85% in the visible region and the estimated direct bandgap value was 3.71 eV. The BATO(2) film also showed relatively low resistivity of 4.415 x 10(-4) Omega cm and sheet resistance of 23.14 Omega/square than films of other concentration. A temperature-dependent electrical conductivity measurement was carried out to investigate the conduction mechanism of the films by estimating the activation energies using Arrhenius plots. Temperature-dependent electrical properties of the films are also theoretically verified using Kroger-Vink notation. At the higher temperature region, the electrical properties were analyzed in terms of ionic carrier concentration and oxygen partial pressure. These experimental results indicate that the Ba and Sb co-doped SnO2 thin film is a potential candidate for alternative transparent conducting electrode application. (C) 2020 Elsevier B.V. All rights reserved.