Influence of substrate temperature on properties of sprayed WO3 thin films

Tungsten oxide (WO3) thin films were deposited by using the spray pyrolysis technique. For the deposition, a 5 mM propanolic solution of ammonium tungstate was sprayed with a 6 ml min−1 spray rate onto the fluorine doped tin oxide coated conducting glass substrates. The substrate temperature was varied from 250 to 450°C, at an interval of 50°C. The influence of the substrate temperature on the structural and optical properties of the WO3 films was studied. The electrochemical properties of WO3 in 0.1 M H2SO4 electrolyte were studied using cyclic-voltammetry and chronoamperometry and various parameters were estimated. The WO3 sample deposited at 350°C having mixed triclinic and hexagonal structure exhibited highest colouration efficiency.