Electrochromic WO3 thin film was prepared by using tungsten metal solution in hydrogen
peroxide as a starting solution and by sol-gel dip coating method. XRD pattern showed that tungsten
oxide crystal phase formed at 400. In the view of electrochemical property, WO3 thin film which
was heat-treated at 300 and was amorphous had better than that of the crystalline phase.
ZnO:Eu3+ films were obtained by dip-coating method and influence of heat treatment on luminescent properties was investigated. Emission and excitation spectra revealed that the organic and nitrate molecules, which adhered on the surface of films when the samples were treated at lower temperatures (300oC-400oC), played an important role on the luminescent properties. At higher temperatures (500oC-800oC), the luminescence spectra of ZnO and Eu3+ were quite different with those treated at lower temperatures. Energy transferred from ZnO host to Eu3+ was obviously observed in the emission and excitation spectra. The luminescence mechanism was discussed briefly.
Nanocrystalline titanium dioxide (TiO2) thin films have been prepared by dip coating method. The TiO2 thin films have been coated on glass substrate and annealed at 400, 450 and 500° C respectively. The X- ray diffraction pattern shows that TiO2 nanocrystalline thin films are of anatase structure and the grain size is found to be in the range of 20-35 nm. The annealed films have been observed to be nanocrystalline in nature and the crystallinity has been observed to improve on annealing. The surface topography of the films has been studied using atomic force microscope. The optical properties have been studied using transmittance spectra. The band gap has been found to lie in the range of 3.70 to 3.83 eV depending on the annealing temperature.
Using TiCl4 and CuCl2 as precursors, the sols were prepared. The coatings of Ti/Cu oxide were formed on both glass and alumina substrates by dip-coating method. XRD results showed that the coatings could be composed of anatase TiO2, CuO and M6O type oxides. The M6O type oxide on glass substrate is in the form of Cu3Ti3O, however is Cu2Ti4O on alumina substrate. The formations of the CuO and M6O are related to the Cu:Ti ratio. A high Cu:Ti ratio corresponds to the CuO, whereas to the M6O. Also the sols were analyzed by infrared spectroscopy and the mechanism of the formation of the coatings was discussed in the paper.
Optical and mechanical characterization of novel cobalt-based metal oxide thin films synthesized using sol–gel dip-coating method