In this study, (SnO2-xFx) thin films where (x = 0, 0.02, 0.04, 0.06 and 0.08) have been deposited by chemical spray pyrolysis method on glass substrates at temperature of (400°C), using Tin Chloride Pentahydrate (SnCl4.5H2O) and Ammonium Fluoride (NH4F) solutions. The structural properties and morphology of these films have been studied using XRD and AFM respectively. XRD analysis showed that these films are polycrystalline in nature with tetragonal Rutile structure with preferred orientation of (110). Doping with Fluorine causes a decrease in the crystallite size. The optical properties for all the films were studied by recording the transmittance and absorbance spectra in the range of (300-900) nm. The results showed that the absorbance increases with increasing the doping percentage. The optical energy gap for allowed direct electronic transition was calculated and it was found that the thin film with 0.08 doping percentage has the least value of 3.72 eV. Urbach energy decreases with increasing doping percentage. The optical constants (absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constant) as a function of photon energy for all prepared films were calculated.
نبيل علي بكر | Nabeel A. Bakr | 5282