Fluorine-doped ZnO thin films deposited by spray pyrolysis technique

Fluorine doped ZnO thin films (FZO) are prepared onto glass substrates at 350 °C by the chemical spray pyrolysis technique. X-ray diffraction spectra show a polycrystalline of ZnO (wurtzite structure) where the amount of fluorine doping affects to preferential orientation (002 plane along c-axis) and does not vary the lattice parameters. Therefore, F introduction in lattice is by the substitution of O-2 ions by F-1 ions. Any variation is observed in transmittance and reflectance measurements in 400–2000 nm wavelength range when samples present F dopant; they have transmittance around 80% in the near infrared and visible zones. The FZO films are degenerate and exhibit n-type electrical conductivity. The best resistivity and mobility are 7.6 × 10-3 Ω cm and 3.77 cm2 V-1 s-1 respectively. The calculated values of the mean free path are very small compared to the grain sizes calculated using XRD measurements. Therefore, we suggest that ionized impurity and/or neutral impurity scattering are the dominant scattering mechanisms in these films.