Investigation of physicochemical properties of (Ti-V)Ox (4.3 at.% of V) functional thin films and their possible application in the field of transparent electronics

During the last decade, functional materials, which simultaneously possess high transmission over the visible light range and good conductivity of electron or hole type electrical conduction at room temperature, have been the subject of interest of many researchers. In this work, (Ti-V)Ox thin films were deposited using the high energy reactive magnetron sputtering method and their structural, chemical, electrical and optical properties were characterized. In order to determine the material composition, energy dispersive spectroscopy measurements were performed and homogeneous concentration of titanium, vanadium and oxygen components as a function of thin film depth was revealed. High resolution transmission electron microscopy investigations as well as selected area electron diffraction patterns confirmed that the thin films were composed of the mixture of nanocrystalline TiO2-V2O5-V2O3 phases. The images of thin films investigated by atomic force microscope revealed a homogeneous, densely packed surface with RMS surface roughness of ca. 2.3 nm. X-ray photoelectron spectroscopy measurements showed that the surface of thin films consists of elements that are specific to the mixture of TiO2 and aforementioned vanadium oxides. Optical properties were determined on the basis of optical spectrophotometry measurements, and the high transmission level of the thin films was confirmed in the visible light range. Based on these results, the refractive index, extinction coefficient and optical band-gap width were estimated. In order to verify the possible application of these thin films in the field of transparent electronics the resistivity and I–V measurements of films deposited on silicon were performed.