Growth, crystal structure and optical properties of Al-doped ZnO thin films

Al-doped ZnO (ZnO:Al) thin films are prepared by high-frequency magnetron sputtering method. The phase analysis and crystal structure refinement are performed using X-ray diffraction data. The mean grain size of the films was determined using the Scherrer formula. The strain and the dislocation density are also calculated. The spectral dependence of the optical transmittance of the obtained sample in the visible and near-infrared regions is studied at room temperature. The integral optical transmittance and the bandgap value of studied films are determined. The optical bandgap value of 3.26 eV is estimated. Based on the obtained experimental results, the refractive index and the high-frequency dielectric constant were determined using the ratio of Tripathy, Moss, Ravindra, and Herve-Vandamme.