材料期刊网

Single and double layers of tungsten oxide and vanadium oxide thin films have been deposited on In2O3:SnO2 (ITO) glass using the pulsed laser deposition (PLD) technique at a substrate heating temperature of 200 degreesC and in rich oxygen pressure. The structural properties and chemical composition of as-deposited WO3(V) and V2O5(Ti) thin films were analyzed using X-ray diffraction (XRD), Raman spectrum (RS), and X-ray photo-electron spectroscopy (XPS). The as-deposited V2O5 doped WO3 thin film on ITO glass showed an amorphous structure. Highly oriented growth nano-crystalline TiO2 doped V2O5 thin films with polycrystalline orthorhombic structure were successfully synthesized on ITO glass using the scanning laser ablation technique at a deposition temperature as low as 200 degreesC. Cyclic voltammograms, at a sweep rate of 50 mV s(-1), show that long-term degradation was noticed for the as-deposited WO3(V) thin film, and no Ion-term degradation was noticed for the as-deposited double layer WO3(V)/V2O5(Ti) thin film. Durability was verified to 8000 cycles in the voltage range between -1.0 and 1.0 V. It is demonstrated that these double layer WO3(V)/V2O5(Ti) thin films on ITO are good candidates for cathode thin films for rechargeable batteries and electrochromic devices. As the additional top layer of V2O5M) possesses nano-crystalline and c-axis oriented structure, which is suitable for Li-ions transport, the cycle stability and reversibility of WO3(V) films have been improved. Double layer WO3(V)/V2O5(Ti) thin films provide a neutral brownish blue electrochromic color. Therefore, this double layer film maybe suitable for most building applications. (C) 2001 Elsevier Science B.V. All rights reserved.