共查询到20条相似文献,搜索用时 15 毫秒
1.
R. Neskovska 《Thin solid films》2007,515(11):4717-4721
Thin cuprous oxide films were prepared by a low cost, chemical deposition (electroless) method onto glass substrates pre-coated with fluorine doped tin oxide. The X-ray diffraction pattern confirmed the Cu2O composition of the films. Visible transmittance spectra of the cuprous oxide films were studied for the as-prepared, colored and bleached films. The cyclic voltammetry study showed that those films exhibited cathode coloring electrochromism, i.e. the films showed change of color from yellowish to black upon application of an electric field. The transmittance across the films for laser light of 670 nm was found to change due to the voltage change for about 50%. The coloration memory of those films was also studied during 6 h, ex-situ. The coloration efficiency at 670 nm was calculated to be 37 cm2/C. 相似文献
2.
The polycrystalline films of Cu2O, prepared by electrodeposition, consist of grains with well-defined geometrical shapes. The size and the orientation of grains which define the surface texture can be controlled by controlling the deposition parameters. Grains with a size ranging from a few tenths of a micrometer to about 10m and with a preferential orientation of the (1 0 0) or (1 1 1) planes parallel to substrates can be obtained under certain deposition conditions. The effect of pH, bath temperature and the rate of deposition on the orientation and the size of grains is discussed. 相似文献
3.
T. Mahalingam J. S. P. Chitra J. P. Chu Hosun Moon Han Joon Kwon Yong Deak Kim 《Journal of Materials Science: Materials in Electronics》2006,17(7):519-523
Cuprous oxide (Cu2O) is an interesting p-type semiconductor with a band gap of 2 eV suitable for solar cell applications. Deposition of Cu2O thin films by electrodeposition from aqueous solutions is a low temperature and inexpensive technique. in the present work,
Cu2O thin films were cathodically deposited on Cu and tin oxide coated glass substrates by the cathodic reduction of copper (II)
lactate solution. The optimized deposition conditions to synthesize cuprous oxide thin films were experimentally identified
as; Deposition potential: −0.555 V versus SCE, pH: 9.0 ± 0.1, Bath temperature: 70∘C. X-ray diffraction studies revealed the formation of single phase cubic Cu2O films. The effect of annealing on the structure and morphology of Cu2O thin films are studied. The dielectric susceptibility, optical conductivity and packing density are evaluated. Photoelectrochemical
solar cells based on p-Cu2O films are constructed. Spectral response studies indicate a peak in photo current density around 600 nm corresponding to
the band gap of Cu2O thin films. The effects of annealing, chemical etching and photo etching on the solar cell parameters are studied. 相似文献
4.
We have used chemical deposition of copper complex solution to prepare CuO thin films on commercial fiberglass. The deposition of copper oxides was done in a beaker using a solution of thiosulfatocuprate (I) as precursor and NaOH as a film conditioner. In order to establish a correlation between experimental conditions and the produced copper species, as well as the film quality, the as deposited and annealed samples were characterized using X-ray diffraction, visible spectrophotometry and atomic force microscopy. The most important result is that a Cu2O 80-nm film can be obtained directly with a short immersion of fiberglass into the copper solution. The film growth of this copper phase occurred in [111] and [200] directions. Moreover, this phase is converted to CuO by annealing at 375 °C. 相似文献
5.
JianBo Liang Naoki KishiTetsuo Soga Takashi JimboMohsin Ahmed 《Thin solid films》2012,520(7):2679-2682
We present an improved preparation method for the growth of high quality crystals of cuprous oxide films grown by thermal oxidation of cupper foils with water vapor. This method proved to be good for preparing cuprous oxide films with high purity and large grain size. X-ray diffraction studies revealed the formation of Cu2O films with preferred (111) orientation. The cuprous oxide diodes fabricated by the above technique have been studied using current-voltage method. 相似文献
6.
G. Torres-Villaseñor R. Barrio-Paredes S. Victor Radcliffe 《Journal of Materials Science》1978,13(10):2164-2170
The stress-strain behaviour under compresion at constant strain rate of single crystals (051 and 122) compression axis) and polycrystalline samples of cuprous oxide have been examined at room temperature and hydrostatic pressure up to 12 kb and at atmospheric pressure and high temperature up to 600° C. At high environmental pressure, plastic flow occurs at 6 kb. At high temperatures and one atmosphere, extensive plastic deformation was observed after 500° C. The resultant slip planes were of the {110} and {100} types. Transmission electron microscopy of thin foils prepared from deformed specimens shows that the Burgers' vectors of the glide dislocations are of the 111, 110 and 100 types. 相似文献
7.
Wen He Xiuying Tian Yi Du Caiyun Sun Xudong Zhang Xiuxiu Han Shanshan Han Xianan Sun Xiaoyong Du Yuanzheng Yue 《Materials science & engineering. C, Materials for biological applications》2010,30(5):758-762
Hollow cuprous oxide (Cu2O) microspheres with a diameter of ca. 1.8 μm are prepared by using yeast as template. The possible mechanism for the formation of the hollow Cu2O spheres is revealed. The biotemplated sample is investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and ultraviolet–visible (UV–vis) absorption spectra. The sample consists of the crystalline Cu2O microspheres with diameters of about 59.5 nm and lattice parameter of 4.264 Å. The observed optical band gap of the product indicates that the blue–shift effect occurs, which is attributed to the hollow Cu2O microspheres. 相似文献
8.
Characterization of copper oxide thin films deposited by the thermal evaporation of cuprous oxide (Cu2O) 总被引:1,自引:0,他引:1
M.F. Al-Kuhaili 《Vacuum》2008,82(6):623-629
Thin films of copper oxide were deposited by thermal evaporation of cuprous oxide (Cu2O) powder. The substrates were either unheated or heated to a temperature of 300 °C. The films were also annealed in air at a temperature of 500 °C for 3 h. The films were characterized by X-ray photoelectron spectroscopy, X-ray diffraction and UV-visible spectrophotometry. The effects of the substrate temperature and post-deposition annealing on the chemical, structural and optical properties of the films were investigated. As-deposited films on unheated substrates consisted of mixed cupric oxide (CuO) and Cu2O phases, with a higher concentration of the Cu2O phase. However, the films deposited on heated substrates and the annealed films were predominantly of the CuO phase. 相似文献
9.
Zhen Zhang Wenbin Hu Yida Deng Cheng Zhong Haoren Wang Yating Wu Lei Liu 《Materials Research Bulletin》2012,47(9):2561-2565
Three conventional complexing agents, including lactic acid, citric acid and EDTA, are applied in the electrodeposition of microcrystalline cuprous oxide (Cu2O) film on indium tin oxide glass substrate. Both scanning electron microscopy and X-ray diffraction have been performed to characterize the morphology and texture of microcrystalline Cu2O film. It is found that the stability constant of copper-based complex compound can obviously influence the deposition overpotential of Cu2O, and the overpotential can significantly alter the growth priority of different planes, which results in oriented growth of Cu2O grains. The quantitative relationships between the stability constant and the deposition overpotential of different complexing agents, as well as the relationship between the overpotential and the formation energy of microcrystalline cuprous oxide's (1 1 0), (1 1 1) and (2 0 0) planes are calculated, respectively. 相似文献
10.
The growth of Cu2O thin films electrodeposited by a two-electrode system with acid and alkaline electrolytes under different values of direct current (DC) densities was investigated. The microstructure of Cu2O thin films produced in the acid electrolyte changes from a ring shape to a cubic shape with increasing DC density, and the microstructure of Cu2O thin films produced in the alkaline electrolyte has a typical pyramid shape. The X-ray diffraction results show that Cu2O thin films can be electrodeposited over a larger current domain than those deposited by a three-electrode system. The growth of Cu2O thin films is examined under this domain, and the electrocrystallization process of such films is discussed taking into consideration the effect of current density on nucleation, cluster growth, and crystal growth. 相似文献
11.
12.
Smaller cuprous oxides (Cu2O) nanocubes were synthesized by solution-phase method at 160 °C, using ethylene glycol reducing Cu(NO3)2·3H2O with poly(vinylypyrrolidone) (pvp) as capping agent. The Cu2O nanocubes were characterized by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and X-ray powder diffraction (XRD). SEM showed that most of Cu2O nanocubes were uniform and monodisperse, with the average edge length about 130 nm. The TEM results were consistent with the SEM results. Selected area electron diffraction (SAED) suggested that as-prepared Cu2O nanocubes were single crystalline. The geometric shape and size of Cu2O nanoparticles were greatly affected by the presence of PVP and its molar ratio (in repeating unit) relative to copper nitrate, temperature and the concentration of Cu(NO3)2·3H2O. The mechanism of Cu2O nanocubes formation was also discussed. 相似文献
13.
Nanowires of Cu2O as well as Cu were synthesized within the anodic aluminum oxide templates in an aqueous acidic electrochemical cell. The content of Cu2O in the copper nanowires was controlled by varying the anodic potential of the pulse-reverse electrolysis and the pH of the electrolyte within a range of 2.0–3.9. For the pH of 2.0, pure Cu nanowires were deposited regardless of the anodic potential. When the anodic potential became higher than the cathodic one, pure Cu2O nanowires were produced at a pH of 3.9. The growth of Cu2O nanowires in the acidic electrolyte was ascribed to the local increase of the pH at the pore base, as well as the capacitive barrier layer of the template. 相似文献
14.
Uniform spheres of nanocrystallite size cuprous oxide particles have been prepared by a simple polyol process using cupric nitrate as a precursor in ethylene glycol. As synthesized compound was dried at 333 K in a vacuum oven and characterized by XRD, FT-IR and SEM techniques. The crystallite size of the cuprous oxide calculated from Scherer's formula was found to be ∼11 nm. 相似文献
15.
The films of CuxS(1x2), prepared by evaporation in vacuum and condensation of stoichiometric sulphides of copper, change their phases by heat treatment in vacuum. Cu2S chalcocite appears as the most stable phase in the range 270 to 450° C and the other sulphur rich phases transform into chalcocite presumably by a loss of sulphur. By electron diffraction we have confirmed the low temperature monoclinic chalcocite phase, the high temperature hexagonal chalcocite phase, the monoclinic djurleite phase, the cubic digenite low and high temperature forms and the hexagonal covellite phase. The low temperature digenite phase presents a superstructure which is similar to that observed by Kazinetset al. on digenite prepared by evaporation in vacuum on a single crystal substrate of NaCl at temperatures of 350 to 400° C. Electron diffraction data of chalcocite (Cu2S), djurleite (Cu1.93S), digenite (Cu1,8S) are presented. 相似文献
16.
AbstractPhase-pure cuprous oxide (Cu2O) crystals are difficult to grow since cupric oxide can form within the crystal as the crystal is cooled to ambient conditions. Vacancies are the solute which causes precipitation of macroscopic defects. Therefore, even when a mostly phase-pure single crystal is used as a feed rod, cupric oxide inclusions persist in the recrystallized solid. Control of the thermal profile during crystal growth, however, can improve phase-purity; a slow counter-rotation rate of the feed and seed rods results in fewer inclusions. Cupric oxide can be removed by annealing, which produces a factor of 540 ± 70 increase in phase-purity. 相似文献
17.
18.
《Materials Science & Technology》2013,29(9):743-747
AbstractA new method of making thin copper strip direct from cuprous oxide powder by an integrated powder technology route has been outlined. The proposed route consists of making, by a slurry method, a green cuprous oxide strip which is subsequently reduced with hydrogen to produce a porous copper strip. The strip is densified by hot rolling to produce a fully dense structure. The combined reduction and sintering behaviour of the green cuprous oxide strip is reported. The mechanism of reduction of the cuprous oxide with hydrogen at various temperatures is discussed, and the geometry of the reaction zone in the green oxide strip is described.MST/183 相似文献
19.
Xiaojun Zhang Guangfeng Wang Haibian Wu Xiaoqing Zhang Huaqiang Wu 《Materials Letters》2008,62(28):4363-4365
Porous cuprous oxide octahedra with a mean diameter of 1 μm have been successfully prepared with high yield via a hydrothermal reduction process at a low temperature. The growth mechanism and the influences of the poly(vinylpyrrolidone) (PVP) and citric acid have been discussed. And then, the samples were used as photocatalytic in the degradation of methyl red (MR). Thanks to the 3D architecture of the product, the photocatalytic performance has been significantly improved. We believe that the present work will open up to systematically explore ways to fabricate porous nanostructures and thus find use in a variety of applications. 相似文献
20.
Thin films of Sm2O3 have been grown on Si(100) and fused quartz by low-pressure chemical vapour deposition using an adducted β-diketonate precursor.
The films on quartz are cubic, with no preferred orientation at lower growth temperatures (∼ 550°C), while they grow with
a strong (111) orientation as the temperature is raised (to 625°C). On Si(100), highly oriented films of cubic Sm2O3 at 625°C, and a mixture of monoclinic and cubic polymorphs of Sm2O3 at higher temperatures, are formed. Films grown on either substrate are very smooth and fine-grained. Infrared spectroscopic
study reveals that films grown above 600° C are free of carbon. 相似文献