The stepwise assembly of negatively charged organic molecules (poly(sodium 4-styrenesulfonate) (PSS) or tetrasodium-meso-tetra(4-sulfonatophenyl) porphine (TPPS)) and positively charged TiO2 colloids on pretreated substrate surfaces utilizing the layer-by-layer (LbL) approach was investigated. The step-by-step formation of these films was studied by UV–vis spectrophotometry and electrochemistry. Photocurrent was generated upon light irradiation of the hybrid thin films assembled on fluorine-doped tin oxide (FTO) conducting glass, which increased linearly as the deposited bilayers increased. In addition, compared to PSS/TiO2 hybrid thin films, the enhancement of the generated photocurrent and the photocurrent response within the wavelength range from 400 to 450 nm were observed in the TPPS/TiO2 hybrid thin films. This was attributed to the dye-sensitized effect of the layered TPPS molecules. It was demonstrated that electrostatic LbL films were attractive systems for the photoelectrochemical investigation, and the control of the generated photocurrent could be achieved by the structure of the multilayered films. 相似文献
The electrochemical reduction of oxides to metals has been studied for decades. Earlier work produced polycrystalline bulk metals. Here, we report that pre-electrodeposited epitaxial face-centered cubic magnetite thin films can be electrochemically reduced to epitaxial body-centered cubic iron thin films in aqueous solution on single-crystalline gold substrates at room temperature. This technique opens new possibilities to produce special epitaxial metal/metal oxide heterojunctions and a wide range of epitaxial metallic alloy films from the corresponding mixed metal oxides. 相似文献
Journal of Solid State Electrochemistry - A study of poly(3-hexylthiophene) (P3HT) thin films by spin-coating process, deposited on conducting glass substrates of fluorine-doped tin oxide (FTO), is... 相似文献
Tungsten oxide thin films, which are cathodic coloration materials that are used in electrochromic devices, were prepared
by a chemical growth method and their electrochromic properties were investigated. The thin films of WO3 were deposited onto electrically conducting substrates: fluorine doped tin oxide coated glass (FTO) with sheet resistance
of about 10 Ω/cm. Transparent, uniform and strongly adherent thin film samples of WO3 were studied for their structural, morphological, optical and electrochromic properties. The XRD data confirmed the monoclinic
crystal structure of WO3 thin films. The direct band gap Eg for the films was found to be 2.95 eV which is good for electrochromic device application.
The electrochromism of WO3 thin film was evaluated in 0.5 M LiClO4/propylene carbonate for Li+ intercalation. Electrochromic properties of WO3 thin films were studied with the help of Cyclic Voltammetry (CV), Chronoamperometry (CA) and Chronocoulometry (CC) techniques. 相似文献
Thin films of copper oxides can be synthesized on substrates by using approaches that are inspired by microbial mineralization processes. In nature, precipitates of manganese and iron oxides with controlled oxidation states and crystal phases are produced through biomineralization by microorganisms. We have previously reported microbial‐mineralization‐inspired approaches that are comprised of direct and intermediate routes for the controlled syntheses of transition‐metal oxides. Herein, these approaches are applied to the thin‐film formation and coating of copper oxides and a related compound with controlled crystal phases and morphologies. Thin films of CuO, Cu2O, and Cu2(OH)3Cl were selectively synthesized by using direct or intermediate routes. Notably, CuO mesocrystal nanosheets formed a thin film over the whole of the substrate. The resultant CuO mesocrystal nanosheets showed enhanced properties for the electrochemical detection of dopamine. This study shows the potential applicability of microbial‐mineralization‐inspired approaches to thin‐film coatings. 相似文献
CdO thin films were deposited on glass, quartz, FTO, silicon wafers of p-type and n-type at 200?°C of substrate temperature employing spray pyrolysis technique using nebulizer. As deposited cadmium oxide thin films were analyzed to find crystallite size, morphology of the substrate, elemental composition and band gap using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDAX) and UV–Vis spectrophotometer. Nature of the thin film was found to be polycrystalline with face centered cubic structure with (111) preferential orientation and evaluated structural parameters show significant effect of used substrates. Spherical sized grains were observed on the surface of the thin films using SEM. The EDAX analysis confirmed that cadmium and oxygen were present in the sample. Direct allowed transition with band gap values lying in the range 2.34–2.44?eV for all the films deposited on various substrates. Among, these thin film coated on FTO substrate was found to have high crystallinity with a narrow band gap, which may be more suitable for opto-electronic applications.
The absorption co-efficient spectra and inset of transmittance spectra with wavelength of CdO thin films at different substrates (Glass, Quartz and FTO).
Multi-layered organic thin films were prepared by stepwise vapor deposition of planar molecules with delocalized π-electrons on indium tin oxide (ITO) glass or KCl crystalline surface. The order of the deposition of π-planar molecules with different redox potential can control enhancement or inhibition of the hole or electron transfer according to the concept of “sequential potential field”, or a potential cascade by the organization of redox components. This concept is here applied to electrochromic or electroluminescent devices composed of multi-layered organic thin films. 相似文献