Optical and Structural Properties of Sol - Gel Derived ZnO:F Thin Films

In the present work, we report the influence of the fluorine doping (two different concentrations) in ZnO films and the annealing temperatures on the film structural, vibrational and optical properties. ZnO:F films are successfully deposited by a facile sol-gel approach. X-Ray diffraction (XRD) analysis shows that F doping induces an improved film crystalinity. The ZnO:F films are polycrystalline with wurtzite structure. Fourier Transform Infrared (FTIR) study reveals that fluorine affects the shapes and positions of the absorption bands. The optical transparency of ZnO:F films is higher than that of undoped ZnO.The optical band gap has been determined from spectrophotometric data. The optical band gap values become narrower with increasing the annealing temperatures, due to the bigger crystallite sizes.