Physical properties and electrochemical behavior of thin layers of vanadium doped cerium dioxide

The present work examines undoped and vanadium (V) doped cerium dioxide (CeO2) thin films prepared by an automated spray pyrolysis technique. The doping concentrations are 2,4, 6, and 8 at.%. Various characterization techniques were carried out to investigate the vanadium effect on the structural as well as the optical properties of the CeO2 films. The study also focused on inspecting the electrochemical characteristics of the CeO2 thin layers. The X-ray diffraction (XRD) results showed the presence of a polycrystalline cubic phase of the fluorite type of the CeO2 material, which is confirmed by results from Raman spectroscopy. The Scanning Electron Microscopy images showed that Vanadium doped films have excellent growth on the ITO substrate with a smooth surface. Optical analysis exhibits a decline in terms of the band gap value and the average transmittance within the visible range by increasing V doping proportions. Electrochemical properties were studied using cyclic voltammetry, which demonstrated that 4 at.% of V doped CeO2 thin films exhibited an excellent capacity to insert and extract the Li+ ions. The pure CeO2 film remained fully transparent after Li+insertion/disinsertion. These interesting results expand the field applications for this material, especially for electrochromic devices.