Facile single-step fabrications of electrochromic WO3 micro-patterned films using the novel photosensitive sol–gel method

Fine-patterned WO3 film was prepared by a photosensitive sol–gel method utilizing tungsten chloride and benzoylacetone (BzAcH) as the starting material and chemical modifier respectively in ethanol. First, the photosensitive sol was obtained by a chelating reaction between tungsten ions and BzAcH. Then, through a single-step patterning process, a fine-patterned WO3 film was fabricated by a photochemical reaction between the chelated complexes and UV light. The structural properties of the films were characterized by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The optical properties of the films tested in the electrochemical cell were determined by optical spectrophotometry in the visible range. The electrochromic properties were studied principally by the cyclic voltammetry (CV) technique.