Optical and electrical properties of fluorine doped tin oxide thin film

Abstract

Thin film of SnO2:F was prepared by spray pyrolysis technique on glass substrate. Surface Morphology, using scanning electron microscope, shows micrograph image with grains size distribution between 16 and 380 nm. Structural characterization by XRD indicates a similar rutile polycrystalline material as SnO2. A four point probe I–V measurement (Van der Pauw method) was used to study electrical properties and the result shows a room temperature sheet resistance of 24 Ω/sq. In addition, a temperature dependence of the electrical response indicates that defect scattering is the main contribution to the DC resistivity. Optical properties were studied by UV–Visible spectroscopy and the spectrum was fitted using Drude-Lorentz model with DC conductivity value (frequency equal to zero) as a fitting condition. Optical result shows average transmittance around 81.2% for the visible frequency range. It indicates a TCO figure of merit value of 5.2 × 10−3 Ω−1. In addition, a first principle calculation using DFT with PBE0 hybrid exchange-correlation was realized to SnO2 and SnO2:F systems in order to understand, from a theoretical point of view, the experimental results. Finally, the FTO film was utilized and evaluated as a transparent electrode in the preparation of a dye-sensitized solar cell.