Microstructure and optical properties of Zn-doped BaTiO₃ thin films

The high-quality BaTiO₃ and Zn-doped BaTiO₃ thin films were prepared on Si substrates by choosing the suitable raw materials and optimizing the preparation of thin films and the post process of annealing. Through the characterization technique of x-ray diffraction (XRD) and atomic force microscope (AFM), the influences of the different doping levels was discussed on the sizes, shapes and uniformities of BaTiO₃ and Zn-doped BaTiO₃ thin films respectively. Raman spectra measurements were carried out to study the lattice vibration modes of thin films. Meanwhile, the type of dopant and the occupied site in the BaTiO₃ lattice were also discussed in detail. For investigating of the mechanism of the doping effects, the optical properties of thin films were studied by spectroscopic ellipsometry furthermore. And the optical constant refractive index and extinction coefficient have been obtained in the wavelength from 400nm to 700nm.