Electrochromic performance of sol–gel deposited V2O5:Ta films

Vanadium and tantalum-doped vanadium pentoxide, V2O5 and V2O5:Ta thin films (2.5 and 5 mol% of Ta) were prepared using sol–gel dip coating technique.The coating solutions were prepared by reacting vanadium (V) oxytripropoxide and tantalum ethoxide (V) as precursors using anhydrous isopropyl alcohol as solvent.The films were deposited on a transparent glass substrate with ITO conducting film by dip coating technique, with a withdrawal of 20 cm/min from the vanadium–tantalum solution and thermally treated at 300 °C for 1 h. The resulting films were characterized by cyclic voltammetry, optical spectroscopy and by X-ray diffraction analysis (XRD). The morphology of the films were studied by atomic force microscopy (AFM). The feasibility for use of these electrodes as ion storage for electrochromic devices was investigated.