Investigation of Optical and Structural Properties of VO2 Thin Films by Thermal Treatment

In this study, VO2 thin films were grown on SiO2 substrate using the PLD method. Then the grown VO2 thin films were subjected to heat treatments at different temperatures and times in the atmosphere environment. The structural properties of the heat-treated films were investigated using X-ray diffraction (XRD) technique and Raman spectroscopy techniques. The surface microstructures of these films were investigated by Scanning Electron Microscope (SEM) technique, and their optical properties and bond structures were investigated by Photoluminescence (PL) spectra and Fourier Transform Infrared Spectroscopy (FTIR) measurements, respectively. Especially XRD and Raman results revealed that heat treatments with high temperature values transformed the films into VO2 and V2O5 mixed-phase crystal structures. Due to the heat treatment carried out in the atmosphere and the high oxygen affinity of the vanadium metal, crystallization took place in both VO2 and V2O5 forms. In order to obtain homogeneous crystalline VO2 structures, heat treatments should be carried out for a long time in oxygen-limited environments.