High Refractive Index Silica-Titania Films Fabricated via the Sol–Gel Method and Dip-Coating Technique—Physical and Chemical Characterization
Magdalena Zięba,
Katarzyna Wojtasik,
Cuma Tyszkiewicz,
Ewa Gondek,
Jacek Nizioł,
Katarzyna Suchanek,
Michał Wojtasik,
Wojciech Pakieła,
Paweł Karasiński
Affiliations
Magdalena Zięba
Department of Optoelectronics, Silesian University of Technology, B. Krzywoustego 2, 44-100 Gliwice, Poland
Katarzyna Wojtasik
Department of Optoelectronics, Silesian University of Technology, B. Krzywoustego 2, 44-100 Gliwice, Poland
Cuma Tyszkiewicz
Department of Optoelectronics, Silesian University of Technology, B. Krzywoustego 2, 44-100 Gliwice, Poland
Ewa Gondek
Department of Physics, Cracow University of Technology, Podchorążych 1, 30-084 Kraków, Poland
Jacek Nizioł
Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow, Poland
Katarzyna Suchanek
Department of Physics, Cracow University of Technology, Podchorążych 1, 30-084 Kraków, Poland
Michał Wojtasik
Oil and Gas Institute—National Research Institute, Lubicz 25A, 31-503 Krakow, Poland
Wojciech Pakieła
Faculty of Mechanical Engineering, Institute of Engineering Materials and Biomaterials, Silesian University of Technology, ul. Konarskiego 18a, 44-100 Gliwice, Poland
Paweł Karasiński
Department of Optoelectronics, Silesian University of Technology, B. Krzywoustego 2, 44-100 Gliwice, Poland
Crack-free binary SiOx:TiOy composite films with the refractive index of ~1.94 at wavelength 632.8 nm were fabricated on soda-lime glass substrates, using the sol–gel method and dip-coating technique. With the use of transmission spectrophotometry and Tauc method, the energy of the optical band gap of 3.6 eV and 4.0 eV were determined for indirect and direct optical allowed transitions, respectively. Using the reflectance spectrophotometry method, optical homogeneity of SiOx:TiOy composite films was confirmed. The complex refractive index determined by spectroscopic ellipsometry confirmed good transmission properties of the developed SiOx:TiOy films in the Vis-NIR spectral range. The surface morphology of the SiOx:TiOy films by atomic force microscopy (AFM) and scanning electron microscopy (SEM) methods demonstrated their high smoothness, with the root mean square roughness at the level of ~0.15 nm. Fourier-transform infrared (FTIR) spectroscopy and Raman spectroscopy were used to investigate the chemical properties of the SiOx:TiOy material. The developed binary composite films SiOx:TiOy demonstrate good waveguide properties, for which optical losses of 1.1 dB/cm and 2.7 dB/cm were determined, for fundamental TM0 and TE0 modes, respectively.
