Electrochromic performance of the mixed V2O5–WO3 thin films synthesized by pulsed spray pyrolysis technique

Vanadium pentoxide (V2O5) mixed tungsten trioxide (WO3) thin films have been synthesized by a novel pulsed spray pyrolysis technique (PSPT) on glass and fluorine doped tin oxide (FTO) coated glass substrates at 400 °C. Aqueous solutions of equimolar vanadium chloride and ammonium tungstate were mixed in volume proportions (5%, 10% and 15%) for the deposition of V2O5–WO3 thin films. The structural, morphological, optical and electrochemical properties of V2O5–WO3 thin films were investigated by FT-IR, XRD, SEM, cyclic voltammetry, chronoamperometry and chronocoulometry techniques. The results showed that the electrochemical properties of V2O5 were altered by mixing WO3. All the films exhibited cathodic electrochromism in lithium containing electrolyte (0.5 M LiClO4 + propylene carbonate (PC)). Maximum coloration efficiency (CE) of about 49 cm2 C−1 was observed for the V2O5 film mixed with 15% WO3. The electrochemical stability of the sample was examined and it was found to be stable up to 1000 cycles.