The influence of annealing on the optical properties of spray-deposited SnO2:F thin films

•Fluorine doped tin oxide thin films were produced by the low cost spray pyrolysis technique.•The films were annealed in nitrogen atmosphere.•The films were characterized by SEM, EDX, and transmittance spectroscopy before and after annealing.•The influence of annealing on the optical parameters of SnO2:F thin films was studied.•These results are important for the use of the films in solar cells and optoelectronic devices.

Polycrystalline, fluorine doped tin oxide (SnO2:F) thin films were prepared by the low cost spray pyrolysis (SP) technique on glass substrates at 400 °C. To study the influence of annealing on the optical properties, the films were annealed in nitrogen atmosphere at 400 °C for 30 min. Scanning electron microscopy (SEM), energy dispersion X-ray spectroscopy (EDX), and transmittance spectroscopy were used to characterize the films. It is found that annealing reduces the transmittance and direct optical bandgap energy, and increases the reflectance, extinction coefficient, refractive index, real and imaginary parts of the dielectric constant, dispersion parameters, loss factor, and optical conductivity. These results are important for the use of tin oxide in solar cells and optoelectronic devices.