Optical response of SrTiO3 thin films grown via a sol-gel-hydrothermal method

Abstract

The polycrystalline SrTiO₃ thin films were prepared by the sol-gel-hydrothermal method on glass substrates. The synthesis pathway was initiated by preparing a clear TiO₂ solution using the sol-gel method. This clear solution was then deposited on a glass substrate using the dip coating technique, followed by the transformation of a thin layer of TiO₂ into SrTiO₃ by the hydrothermal method. The crystal structure, bond interactions, and band gap energy of SrTiO₃ thin layers were characterized using X-ray Diffraction (XRD), Fourier Transform Infra-Red spectroscopy (FTIR), and UV–Vis Diffuse Reflectance Spectroscopy (UV-DRS). The XRD patterns of all SrTiO₃ thin layers indicated the perovskite structure of the samples. The FTIR spectrum showed an interaction of the silanol groups on the surface of the glass substrate with Ti–O–Ti of SrTiO₃ layers. The characteristics of the UV-DRS spectrum were influenced by the thickness of the SrTiO₃ layer formed on the glass substrate. The findings of this work provide insights for producing SrTiO₃ layers with specified thickness and morphology.