Structural, optical and electrical properties of F-doped ZnO nanorod semiconductor thin films deposited by sol–gel process

Structural, optical and electrical properties of fluorine-doped ZnO nanostructure semiconductor thin films prepared by sol–gel spin coating method have been investigated. The thin films have polycrystalline structure with a preferential growth along the ZnO (0 0 2) plane. The grain size for the films was found to be in the range of 24–35 nm. Scanning electron microscopy (SEM) images clearly revealed that the 10% F-doped ZnO film was composed of nanorods. Transmittance spectra of the films indicate that the films have high transparency. The optical band gap and Urbach energy of the F-doped ZnO films vary with fluorine doping. The refractive index dispersion curve of 20% F-doped ZnO film obeys the single-oscillator model. The dispersion parameters, Eo and Ed were found to be 6.104 and 12.045 eV, respectively. For 10% F-doped ZnO film, temperature-dependent conductivity studies revealed that the conduction mechanism is changed from the thermally activated conductivity to the grain boundary scattering with increase in temperature.