Spectroscopic Ellipsometry of BaxSr1?xTiO3 Thin Films Prepared by the Sol-Gel Method

Abstract

Subject classification: 77.55.+f; 78.20.Ci; 81.20.Fw Stoichiometric Ba x Sr 1Àx TiO 3 (BST) thin films with various values of x were prepared on Si(100) substrates by the sol-gel method. The influence of Sr content on the structure and the optical properties was studied by X-ray diffraction (XRD) and spectroscopic ellipsometry (SE) in the UV-visible region. The measured SE spectra were analyzed with an appropriate procedure to accurately determine the thickness and the optical constants of thin films. It has been found that the optical constants of the BST films are functions of the film composition. The optical bandgap energy increases with the increasing of Sr content.

Optical and electro-optic anisotropy of epitaxial Ba0.7Sr0.3TiO3 thin films

“…19 Meanwhile, voids caused by surface roughness and porosity inside the film is another controlling factor for the variation of refractive index. 19,20 Moreover, changes in electronic structure due to lattice distortion and some variations in atomic coordinate 8 may also be responsible for the observed variation in refractive index of differently oriented BST thin films. Electro-optic properties of the Ba 0.7 Sr 0.3 TiO 3 thin films were measured with a transverse geometry at the wavelength of 632.8 nm using modified Sénarmont method.…”

Photoluminescence at room temperature in polycrystalline BaxSr1−xTiO3 ceramics obtained by solid-state reaction method

“…Tian et al [14] and Yang et al [15] [16,17]. The excitation energy (514.5 nm, 2.4 eV) used in our work is too low to excite the electrons from the valence band (VB) to conduction band (CB) in BST ceramics.…”

Epitaxial (Ba,Sr)TiO3 Ferroelectric Thin Films for Integrated Optics

“…This lowest energy oscillator is the largest contributor to the dispersion of the refractive index . Meanwhile, voids caused by surface roughness and porosity inside the film is another controlling factor for the variation of refractive index Yang et al, 2002). Moreover, changes in electronic structure due to lattice distortion and some variations of atomic coordination caused by the substrate orientations may also be responsible for the observed variation in refractive index of differently oriented BST thin films.…”