Growth regulation of WO3 film by H2C2O4 during chemical bath deposition

In this study, a two-step chemical bath deposition-annealing process was used to fabricate WO3 films on a fluorine-doped tin oxide basement. By controlling the reactant amounts, the growth and thickness of the as -prepared H2WO4 and WO3 films can be regulated. A possible three-step growth mechanism was identified to describe the growth of H2WO4 films. The morphology, structure, and light response of the as-fabricated films were characterized by X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared diffuse -reflectance spectroscopy, among other methods. Photoluminescence spectroscopy was used to test the separa-tion, recombination, and transportation of photogenerated carriers. The results indicate the inhibition of the photogenerated carrier recombination rate in the WO3 film with decreasing thickness.