Preparation of ZnO film on p-Si and I-V characteristics of p-Si/n-ZnO

Directory of Open Access Journals (Sweden)

Shampa Mondal

2013-02-01

Full Text Available Zinc oxide (ZnO thin films were deposited on p-silicon (Si substrate from ammonium zincate bath following a chemical dipping technique called SILAR. Films in the thickness range 0.5-4.5 µm could be prepared by varying the number of dipping for a fixed concentration (0.125 M of zincate bath and fixed pH (11.00-11.10. Higher values of dipping produced nonadherent and poor quality films. Structural characterization by X-ray diffraction (XRD indicates the formation of polycrystalline single phase ZnO with strong c-axis orientation. The structural characteristics of the films were found to be a sensitive function of film thickness. The degree of orientation was found to be a function of film thickness and a maximum was found at around 2.2 µm. Scanning electron microscopy (SEM reveals the formation of sub-micrometer crystallites on silicon substrate. The coverage of crystallites (grains on substrate surface increases with number of dipping. Dense film containing grains distributed throughout the surface is obtained at large thicknesses. The ohmic nature of silver (Ag on ZnO and Aluminum (Al on p-Si was confirmed by I-V measurements. I-V characteristic of the p-Si/n-ZnO heterojunction was studied and rectification was observed. The maximum value of forward to reverse current ratio was ~15 at 3.0 V.

Preparation and characterization of chitosan/ZnAl2O4 films

International Nuclear Information System (INIS)

Araujo, P.M.A.G.; Santos, P.T.A.; Rodrigues, P.A.; Costa, A.C.F.M.; Araujo, E.M.

2012-01-01

Chitosan films have been explored for biomedical application, as the chitosan to be, low toxicity, abundant in nature, show affinity for dispersion loads and high mechanical strength. On the other hand, ZnAl 2 O 4 has energy gap of approximately 3.8 eV, which makes it useful for use as photoelectric device ultraviolet. Thus, this work has as objective to prepare films of quitosana/ZnAl 2 O 4 in proportions of 5:1, 5:2, 5:3, 5:4 and evaluate the structural, morphological and thermals characteristics. To this end, ZnAl2O4 first nanoparticles (NPs) was deagglomerated and 325 mesh sieve and added to chitosan diluted in 1% acetic acid, and dried at 60°C. After drying, a solution of 1M sodium hydroxide was added to obtain a film with neutral pH. The films were characterized by XRD, SEM and TG. For all proportions evaluated it was verified the presence of ZnAl 2 O)4 and chitosan phases. By micrographs, it was observed that there was formation of agglomerates of ZnAl 2 O 4 NPs both on the surface of the films, the encapsulated in chitosan. In all samples the ratio 5:4 showed the greatest consistency both in relation to the film surface of the nanoparticles in the chitosan matrix. TG/DTA curves of quitosana/ZnAl 2 O 4 film for all the samples showed that for the concentration of 5:1 to 5:3 occurred three mass loss while for concentration of 5:2 to 5:4 were only two stages decomposition. (author)

Structural, optical and thermal properties of {beta}-SnS{sub 2} thin films prepared by the spray pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Khelia, C.; Ben Nasrallah, T.; Amlouk, M.; Belgacem, S. [Faculte des Sciences, Tunis (Tunisia). Lab. de Physique de la Matiere Condensee; Maiz, F. [Equipe de Photothermique de Nabeul, Inst. Preparatoire aux Etudes d' Ingenieur de Nabeul (Tunisia); Mnari, M. [Lab. de Chimie Analytique, Campus Univ., Tunis (Tunisia)

2000-03-01

Tin disulfide {beta}-SnS{sub 2} thin films have been prepared on pyrex substrates by the spray pyrolysis technique using tin tetrachloride and thiourea as starting materials. The depositions were carried out in the range of substrate temperatures from 240 to 400 C. Highly c-axis oriented {beta}-SnS{sub 2} films, having a strong (001) X-ray diffraction line are obtained at temperature 280 C and using concentration ratio in solution R = [S]/[Sn] = 2.5. Films surfaces were analyzed by contact atomic force microscopy (AFM) and by scanning electron microscopy (SEM) in order to understand the effect of the deposited temperature on the surface structure. On the other hand, from transmission and reflection spectra, the band gap energy determined is about 2.71 eV. Finally using the photodeflection spectroscopy technique, the thermal conductivity K{sub c} and diffusivity D{sub c} were obtained. Their values are 10 Wm{sup -1}K{sup -1} and 10{sup -5} m{sup 2}s{sup -1} respectively. (orig.)

Solar control on irradiated Ta2O2 thin films

International Nuclear Information System (INIS)

Baydogan, N. D.; Zayim, E. Oe.

2007-01-01

Thin films consisting of Ta 2 O 5 have been used in industry in applications related to thin-film capacitors, optical waveguides, and antireflection coatings on solar cells. Ta 2 O 5 films are used for several special applications as highly refractive material and show different optical properties depending on the deposition methods. Sol-gel technique has been used for the preparation of Ta 2 O 5 thin films. Ta 2 O 5 thin films were prepared by sol-gel proses on glass substrates to obtain good quality films. These films were exposed to gamma radiation from Co-60 radioisotope. Ta 2 O 5 coated thin films were placed against the source and irradiated for 8 different gamma doses; between 0.35 and 21.00 kGy at room temperature. Energetic gamma ray can affect the samples and change its colour. On the other hand some of the Ta 2 O 5 coated thin films were irradiated with beta radiation from Sr-90 radioisotope. The effect of gamma irradiation on the solar properties of Ta 2 O 5 films is compared with that of beta irradiation. The solar properties of the irradiated thin films differ significantly from those of the unirradiated ones. After the irradiation of the samples transmittance and reflectance are measured for solar light between 300 and 2100 nm, by using Perkin Elmer Lambda 9 UV/VIS/NIR Spectrophotometer. Change in the direct solar transmittance, reflectance and absorptance with absorbed dose are determined. Using the optical properties, the redistribution of the absorbed component of the solar radiation and the shading coefficient (SC) are calculated as a function of the convective heat-transfer coefficient. Solar parameters are important for the determination of the shading coefficient. When the secondary internal heat transfer factor (qi), direct solar transmittance (□ e ), and solar factor (g) are known, it is possible to determine shading coefficient via the dose rates. The shading coefficient changes as the dose rate is increased. In this study, the shading

Nd3-xBixFe4GaO12 (x = 2, 2.5 films on glass substrates prepared by MOD method

Directory of Open Access Journals (Sweden)

Yoshida T.

2014-07-01

Full Text Available We studied Nd3-XBiXFe4GaO12 films to obtain perpendicular magnetic anisotropy as well as large Faraday effect. NdBi2Fe4GaO12 (Bi2:NIGG and Nd0.5Bi2.5Fe4GaO12 (Bi2.5:NIGG films were obtained on Nd2BiFe4GaO12 (Bi1:NIGG layer prepared on glass substrates by metal-organic decomposition (MOD method. Bi2:NIGG and Bi2.5:NIGG films showed large Faraday rotation angles of 7.5 and 10.5 degree/µm, at a wavelength of 520 nm, respectively. Those films have perpendicular magnetic anisotropy with a coercivity of 350 Oe and a saturation magnetic field of 730 Oe.

TiO2 and Cu/TiO2 Thin Films Prepared by SPT

Directory of Open Access Journals (Sweden)

S. S. Roy

2015-12-01

Full Text Available Titanium oxide (TiO2 and copper (Cu doped titanium oxide (Cu/TiO2 thin films have been prepared by spray pyrolysis technique. Titanium chloride (TiCl4 and copper acetate (Cu(CH3COO2.H2O were used as source of Ti and Cu. The doping concentration of Cu was varied from 1-10 wt. %. The X-ray diffraction studies show that TiO2 thin films are tetragonal structure and Cu/TiO2 thin films implies CuO has present with monoclinic structure. The optical properties of the TiO2 thin films have been investigated as a function of Cu-doping level. The optical transmission of the thin films was found to increase from 88 % to 94 % with the addition of Cu up to 8 % and then decreases for higher percentage of Cu doping. The optical band gap (Eg for pure TiO2 thin film is found to be 3.40 eV. Due to Cu doping, the band gap is shifted to lower energies and then increases further with increasing the concentration of Cu. The refractive index of the TiO2 thin films is found to be 2.58 and the variation of refractive index is observed due to Cu doped. The room temperature resistivity of the films decreases with increasing Cu doping and is found to be 27.50 - 23.76 W·cm. It is evident from the present study that the Cu doping promoted the thin film morphology and thereby it is aspect for various applications.

Application of V2O5 thin films deposited by laser ablation in micron batteries of solid state

International Nuclear Information System (INIS)

Escobar A, L.; Camps, E.; Haro P, E.; Camacho L, M.A.; Julien, C.

2001-01-01

The obtained results from synthesizing V 2 O 5 thin films by laser ablation are presented. Depending on the deposit conditions V 2 O 5 thin films have been grown as amorphous as a crystalline ones with preferential orientation. The results of the electrochemical characterization of one of the synthesized layers are presented when being manufactured joint with it a micron battery. (Author)

Structural and optical properties of {beta}-FeSi{sub 2}/Si(100) prepared by laser ablation method

Energy Technology Data Exchange (ETDEWEB)

Kakemoto, H; Makita, Y; Obara, A; Tsai, Y; Sakuragi, S; Ando, S; Tsukamoto, T

1997-07-01

{beta}-FeSi{sub 2} is a promising material for the application of various electronic, optoelectronic and energy devices. The authors present here the semiconducting properties of {beta}-FeSi{sub 2} films on Si(100) substrate prepared by laser ablation method. Samples were grown using poly-crystalline bulk {beta}-FeSi{sub 2} prepared by horizontal gradient freeze method. For the monitoring of growth, in-situ observation of ablation plume was made through fluorescence spectroscopy. Reflection of high-energy electron beam diffraction (RHEED) was also made in-situ to see the surface morphology. Characterization of the films by X-ray diffraction presented purely {beta}(220) orientation. Raman scattering measurements at room temperature also indicated that the grown films are semiconducting {beta}-FeSi{sub 2}. Optical absorption spectra at room temperature showed absorption coefficient higher than 10{sup 5} cm{sup {minus}1} above the band-gap ({approximately}1.2 eV). It was revealed that high quality semiconducting {beta}-FeSi{sub 2} films can be fabricated by laser ablation method without post-annealing.

Synthesis of V-doped TiO{sub 2} films by chemical bath deposition and the effect of post-annealing on their properties

Energy Technology Data Exchange (ETDEWEB)

Shopova-Gospodinova, Denitsa [Institut fuer Materialwissenschaft, Universitaet Stuttgart, Heisenbergstrasse 3, D-70569 Stuttgart (Germany); Jeurgens, Lars P.H.; Welzel, Udo [Max-Planck-Institut fuer Intelligente Systeme (formerly MPI for Metals Research), Department Mittemeijer, Heisenbergstrasse 3, D-70569 Stuttgart (Germany); Bauermann, Luciana Pitta; Hoffmann, Rudolf C. [Institut fuer Materialwissenschaft, Universitaet Stuttgart, Heisenbergstrasse 3, D-70569 Stuttgart (Germany); Bill, Joachim, E-mail: mwishopova@imw.uni-stuttgart.de [Institut fuer Materialwissenschaft, Universitaet Stuttgart, Heisenbergstrasse 3, D-70569 Stuttgart (Germany)

2012-07-01

Amorphous composite films, composed of a Ti{sub 1-x}V{sub x}O{sub 2} solid-solution phase and a V{sub 2}O{sub 5} phase, were produced by chemical bath deposition and subsequently air-annealed at various temperatures up to 550 Degree-Sign C. The microstructure and chemical composition of the as-prepared and annealed films were investigated by a combinatorial experimental approach using Scanning electron microscopy, X-ray powder diffraction and X-ray photoelectron spectroscopy. Ultraviolet-Visible Spectrometry was applied to determine the optical band gap of the as-prepared and annealed films. It followed that the incorporation of vanadium in the as-deposited films reduces the optical band gap of TiO{sub 2} from about 3.8 eV to 3.2 eV. Annealing of the films up to 350 Degree-Sign C leads to slight increase of band gap, as attributed to a reduction of the defect density in the initially amorphous oxide films due to the gradual development of long-range order and a concurrent reduction of the V{sup 4+}-dopant concentration in the Ti{sub 1-x}V{sub x}O{sub 2} solid-solution phase. The films crystallized upon annealing in air at 550 Degree-Sign C, which resulted in drastic changes of the phase constitution, optical absorbance and surface morphology. Due to the lower solubility of V{sup 4+} in crystalline TiO{sub 2}, V{sup 4+} segregates out of the crystallizing Ti{sub 1-x}V{sub x}O{sub 2} solid-solution phase, forming crystalline V{sub 2}O{sub 5} at the film surface. - Highlights: Black-Right-Pointing-Pointer Incorporation of vanadium in TiO2 thin film reduces its optical band gap. Black-Right-Pointing-Pointer Amorphous V-doped TiO2 and TiO2-V2O5 composite films were air-annealed up to 550 Masculine-Ordinal-Indicator C. Black-Right-Pointing-Pointer Annealing of the films up to 350 Degree-Sign C leads to slight increase of the band gap.

Correlation of optical energy gap with the nearest neighbour short range order in amorphous V2O5 films

International Nuclear Information System (INIS)

Dhawan, Sahil; Vedeshwar, Agnikumar G; Tandon, R P

2011-01-01

The optical and structural properties of well characterized vacuum-evaporated amorphous V 2 O 5 films were studied in the thickness range 5-500 nm. The structural analyses show that V-O, O-O and V-V nearest neighbour distances defining the short range order vary nonlinearly with film thickness. The optical absorption shows thickness-dependent energy gap (E g ) and the nonlinear behaviour of thickness-dependent E g is similar to that of nearest neighbour distance with film thickness. The E g correlates linearly very well with all the three nearest neighbour distances. The variation of E g with film thickness is attributed to the residual stress in the film which causes the changes in short range order. The change in E g corresponding to the change in V-O distance was found to be 35 eV nm -1 . This change is almost three times of that with V-V distance.

Reversible superhydrophilicity and hydrophobicity switching of V2O5 thin films deposited by magnetron sputtering

Science.gov (United States)

Zhang, Chunzi; Peng, Zhiguang; Cui, Xiaoyu; Neil, Eric; Li, Yuanshi; Kasap, Safa; Yang, Qiaoqin

2018-03-01

V2O5 thin films are well-known "smart" materials due to their reversible wettability under UV irradiation and dark storage. Their surfaces are usually hydrophobic and turn into hydrophilic under UV irradiation. However, the V2O5 thin films deposited by magnetron sputtering in present work are superhydrophilic and turned into hydrophobic after days' of storage in air. This change can be recovered by heating. The effects of many factors including surface roughness, irradiation from visible light, UV, & X-ray, and storage in air & vacuum on the reversible switching of wettability were investigated. The results show that air absorption is the main factor causing the film surface change from superhydrophilicity to hydrophobicity.

Magnetic and optical properties of MgAl2O4-(Ni0.5Zn0.5Fe2O4 thin films prepared by pulsed laser deposition

Directory of Open Access Journals (Sweden)

Takeshi Misu, Naonori Sakamoto, Kazuo Shinozaki, Nobuyasu Adachi, Hisao Suzuki and Naoki Wakiya

2011-01-01

Full Text Available Thin films composed of MgAl2O4 and (Ni0.5Zn0.5Fe2O4 ([MA(100-x-NZFx] films were grown on fused SiO2 substrates by pulsed laser deposition. X-ray diffraction measurements revealed that the films were polycrystalline, and that their lattice constant varied linearly with composition, indicating the formation of a solid solution. The film with x=60 was paramagnetic and those with x ≥ 70 were ferromagnetic. The films had a transparency above 75% in the visible range, but the transparency decreased with the x value. The optical band gaps were 2.95, 2.55, 2.30 and 1.89 eV for x=20, 40, 60, 80 and 100, respectively. The Faraday rotation angle increased with x in the visible range, and the film with x=70 exhibited a value of 2000 degrees cm-1 at 570 nm, which is comparable to the rotation angle of Y3Fe5O12. Owing to their high transparency, which extends into the visible range, the [MA(100-x-NZFx] films can be used in novel magneto-optical devices.

A Highly Thermostable In2O3/ITO Thin Film Thermocouple Prepared via Screen Printing for High Temperature Measurements

Directory of Open Access Journals (Sweden)

Yantao Liu

2018-03-01

Full Text Available An In2O3/ITO thin film thermocouple was prepared via screen printing. Glass additives were added to improve the sintering process and to increase the density of the In2O3/ITO films. The surface and cross-sectional images indicate that both the grain size and densification of the ITO and In2O3 films increased with the increase in annealing time. The thermoelectric voltage of the In2O3/ITO thermocouple was 53.5 mV at 1270 °C at the hot junction. The average Seebeck coefficient of the thermocouple was calculated as 44.5 μV/°C. The drift rate of the In2O3/ITO thermocouple was 5.44 °C/h at a measuring time of 10 h at 1270 °C.

Thermal and electrical properties of 60V2O5–5P2O5–(35− x) B2O3 ...

Indian Academy of Sciences (India)

The samples of composition 60V2O5–5P2O5–(35−)B2O3–CeO2, = 1, 2, 3, 4 and 5 mol% were prepared by the melt-quench method. The prepared samples were characterized by X-ray diffraction, thermogravimetric-differential thermal analysis and impedance spectroscopy. The activation energies were evaluated ...

Evidence of the semiconductor-metal transition in V{sub 2}O{sub 5} thin films by the pulsed laser photoacoustic method

Energy Technology Data Exchange (ETDEWEB)

Perez-Pacheco, A.; Acosta-Najarro, D. R.; Cruz-Manjarrez, H.; Rodriguez-Fernandez, L.; Pineda-Santamaria, J. C; Aguilar-Franco, M. [Instituto de Fisica-Universidad Nacional Autonoma de Mexico, Mexico DF (Mexico); Castaneda-Guzman, R. [Laboratorio de Fotofisica y Peliculas Delgadas, CCADET-UNAM, Mexico DF (Mexico)

2013-05-14

In this work, the pulsed photoacoustic technique was used to investigate the semiconductor-metal transition of thin vanadium pentoxide films (V{sub 2}O{sub 5}) under increasing temperature. The V{sub 2}O{sub 5} thin films were simultaneously deposited by RF magnetron sputtering at room temperature, on corning glass and SnO{sub 2}:F/glass substrates, in order to compare the photoacoustic response. The elemental and structural analysis of the V{sub 2}O{sub 5} films was performed by Rutherford backscattering spectroscopy and X-ray diffraction. The optical transmission and band gap were determined using UV-Vis spectroscopy. The electrical properties were measured using four-point probe measurements with the Van der Pauw geometry.

Single-phase {beta}-FeSi{sub 2} thin films prepared on Si wafer by femtosecond laser ablation and its photoluminescence at room temperature

Energy Technology Data Exchange (ETDEWEB)

Lu Peixiang [State Key Laboratory of Laser Technology and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)]. E-mail: lupeixiang@mail.hust.edu.cn; Zhou Youhua [State Key Laboratory of Laser Technology and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China) and Physics and Information School, Jianghan University, Wuhan 430056 (China)]. E-mail: yhzhou@jhun.edu.cn; Zheng Qiguang [State Key Laboratory of Laser Technology and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Yang Guang [State Key Laboratory of Laser Technology and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)

2006-02-06

Single-phase {beta}-FeSi{sub 2} thin films were prepared on Si(100) and Si(111) wafers by using femtosecond laser deposition with a FeSi{sub 2} alloy target for the first time. X-ray diffraction (XRD), field scanning electron microscopy (FSEM), scanning probe microscopy (SPM), electron backscattered diffraction pattern (EBSD), and Fourier-transform Raman infrared spectroscopy (FTRIS) were used to characterize the structure, composition, and properties of the {beta}-FeSi{sub 2}/Si films. The orientation of {beta}-FeSi{sub 2} grains was found to depend on the orientation of the Si substrates, and photoluminescence at wavelength of 1.53 {mu}m was observed from the single-phase {beta}-FeSi{sub 2}/Si thin film at room temperature (20 {sup o}C)

Preparation of n-type semiconductor SnO2 thin films

International Nuclear Information System (INIS)

Rahal, Achour; Benramache, Said; Benhaoua, Boubaker

2013-01-01

We studied fluorine-doped tin oxide on a glass substrate at 350°C using an ultrasonic spray technique. Tin (II) chloride dehydrate, ammonium fluoride dehydrate, ethanol and NaOH were used as the starting material, dopant source, solvent and stabilizer, respectively. The SnO 2 : F thin films were deposited at 350°C and a pending time of 60 and 90 s. The as-grown films exhibit a hexagonal wurtzite structure and have (101) orientation. The G = 31.82 nm value of the grain size is attained from SnO 2 : F film grown at 90 s, and the transmittance is greater than 80% in the visible region. The optical gap energy is found to measure 4.05 eV for the film prepared at 90 s, and the increase in the electrical conductivity of the film with the temperature of the sample is up to a maximum value of 265.58 (Ω·cm) −1 , with the maximum activation energy value of the films being found to measure 22.85 meV, indicating that the films exhibit an n-type semiconducting nature. (semiconductor materials)

Influence of solution deposition rate on properties of V_2O_5 thin films deposited by spray pyrolysis technique

International Nuclear Information System (INIS)

Abd–Alghafour, N. M.; Ahmed, Naser M.; Hassan, Zai; Mohammad, Sabah M.

2016-01-01

Vanadium oxide (V_2O_5) thin films were deposited on glass substrates by using a cost-efficient spray pyrolysis technique. The films were grown at 350° through thermal decomposition of VCl_3 in deionized water with different solution spray rates. The high resolution X-ray diffraction results revealed the formation of nanocrystalline films having orthorhombic structures with preferential orientation along (101) direction. The spray rate influenced the surface morphology and crystallite size of the films. The crystallite size was found to increase whereas the micro-strain was decreased by increasing the spray deposition rates. The increase in crystallite size and decrease in the macrostrain resulted in an improvement in the films’ crystallinity. The UV-Visible spectroscopy analysis indicated that the average transmittance of all films lies in the range 75-80 %. The band gap of V_2O_5 film was decreased from 2.65 to 2.46 eV with increase of the spray deposition rate from 5 ml/min to 10 ml/min. first, second, and third level headings (first level heading).

Effect of nickel seed layer on growth of α-V{sub 2}O{sub 5} nanostructured thin films

Energy Technology Data Exchange (ETDEWEB)

Sharma, Rabindar Kumar; Kant, Chandra; Kumar, Prabhat; Singh, Megha, E-mail: meghasingh-08@yahoo.com; Reddy, G. B. [Thin film Laboratory, Department of Physics, Indian Institute of Technology Delhi-110016 (India)

2015-08-28

In this communication, we reported the role of Ni seed layer on the growth of vanadium pentoxide (α-V{sub 2}O{sub 5}) nanostructured thin films (NSTs) using plasma assisted sublimation process (PASP). Two different substrates, simple glass substrate and the Ni coated glass substrate (Ni thickness ∼ 100 nm) are employing in the present work. The influence of seed layer on structural, morphological, and vibrational properties have been studied systematically. The structural analysis divulged that both films deposited on simple glass as well as on Ni coated glass shown purely orthorhombic phase, no other phases are detected. The morphological studies of V{sub 2}O{sub 5} film deposited on both substrates are carried out by SEM, revealed that features of V{sub 2}O{sub 5} NSTs is completely modified in presence of Ni seed layer and the film possessing the excellent growth of nanorods (NRs) on Ni coated glass rather than simple glass. The HRTEM analysis of NRs is performed at very high magnification, shows very fine fringe pattern, which confirmed the single crystalline nature of nanorods. The vibrational study of NRs is performed using micro-Raman spectroscopy, which strongly support the XRD observations.

Friedel-Crafts Alkylation of o-xylene over V2O5/ZrO2 Catalysts

CSIR Research Space (South Africa)

Kesavan Pillai, Sreejarani

2012-01-01

Full Text Available The present study has undertaken the Friedel-Crafts benzylation of aromatics over the V2O5/ZrO2 catalysts systems. Catalysts with different V2O5 content (0-15wt %) was prepared by wet impregnation method and characterized by XRD, BET surface area...

Effect of Mn doping on the structural and optical properties of ZrO2 thin films prepared by sol–gel method

International Nuclear Information System (INIS)

Berlin, I. John; Lekshmy, S. Sujatha; Ganesan, V.; Thomas, P.V.; Joy, K.

2014-01-01

Homogeneous and transparent Mn doped ZrO 2 thin films were prepared by sol–gel dip coating method. The films were annealed in air atmosphere at 500 °C. The X-ray diffraction pattern of the undoped ZrO 2 thin film revealed a mixed phase of tetragonal and monoclinic ZrO 2 with preferred orientations along T(111) and M(− 111). Grazing Incidence X-ray Diffraction of Mn doped ZrO 2 thin films reveals the introduction of Mn interstitial in ZrO 2 which stabilize the mixed phase of ZrO 2 into tetragonal phase. Atomic force microscope image shows the addition of catalyst (Mn) which stops isotropic agglomeration of particles, instead of anisotropic agglomeration that occurred resulting in growth of particles in certain direction. Average transmittances of > 70% (in UV–vis region) were observed for all samples. The optical band gap decreased from 5.72 to 4.52 eV with increase in Mn doping concentration. The reduced band gap is due to the introduction of impurity levels in the band gap, by incorporation of the metal ions into the ZrO 2 lattice. The d-electron of Mn (t 2g level) can easily overlap with the ZrO 2 's valence band (VB) because t 2g of Mn is very close to VB of ZrO 2 . This overlap caused a wide VB and consequently decreases the band gap of ZrO 2 . The photoluminescence (PL) spectrum of undoped zirconia thin film exhibits an intense near band edge emission peak at 392.5 nm (3.15 eV) and weak emission peaks at 304 (4.07 eV), 604 nm (2.05 eV) and 766 nm (1.61 eV). Additional PL peaks were observed for Mn doped ZrO 2 located at around 420, 447 (blue), 483 (blue) and 529 (green) nm respectively. These peaks were due to the redox properties of various valence state of Mn in ZrO 2 . The prepared Mn doped ZrO 2 thin films can be applied in optical devices. - Highlights: • Mn-doped ZrO 2 thin films were prepared by sol–gel dip coating method. • Introduction of Mn interstitial in ZrO 2 stabilizes ZrO 2 into tetragonal phase. • The optical band gap

Effect of aging of V{sub 2}O{sub 5} sol on properties of nanoscale films

Energy Technology Data Exchange (ETDEWEB)

Senapati, Sujata [Materials Science Programme, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Samtel Centre for Display Technologies, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Panda, Siddhartha, E-mail: spanda@iitk.ac.in [Materials Science Programme, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Samtel Centre for Display Technologies, Indian Institute of Technology Kanpur, Kanpur 208016 (India)

2016-01-29

Nanoscale films having thicknesses in the range of 92 nm–137 nm were obtained by spin coating V{sub 2}O{sub 5} sol at different stages of aging. The observed structural and morphological changes with time can be attributed to the reactions occurring in the sol. The film morphology changed from an indistinctive featureless film to a homogenous film having ribbon-like nanostructures with aging of sols. TGA and FTIR analysis confirmed loss in the amount of intercalated water content with aging giving rise to structural changes (decrease in interlayer spacing) which were observed using XRD. Variations in mechanical, electrical, and optical properties of the thin films were observed with aging of the sol. Strain in the films were found to decrease with aging. The electrical conductivity increased with aging and this can be correlated to the improved crystallinity of the films with aging. The optical bandgap (calculated from UV–Vis data) decreased and the transmittance increased with aging. - Highlights: • Nanoscale V{sub 2}O{sub 5} films synthesized by spin coating progressively aged sol. • Structural and morphological changes were observed in the films. • Loss of water of hydration resulted in decrease in interlayer spacing. • Strain in the film decreased and conductivity increased with aging. • Increase in transmittance and decrease in optical band gap with aging observed.

Effects of the precursor concentration and different annealing ambients on the structural, optical, and electrical properties of nanostructured V2O5 thin films deposited by spray pyrolysis technique

Science.gov (United States)

Irani, Rowshanak; Rozati, Seyed Mohammad; Beke, Szabolcs

2018-04-01

V2O5 thin films were deposited with different precursor concentrations of 0.01, 0.05, and 0.1 M on glass substrates by spray pyrolysis technique, then the optimized films were annealed in different ambients (air, oxygen, and vacuum). The results showed that by increasing the concentration, the films grew along the (001) direction with an orthorhombic structure. Field emission scanning electron microscopy showed that nanorods were formed when depositing 0.05 molar of VCl3. We conclude that with the precursor concentration, the surface nanostructure can be well-controlled. Annealing improved the crystallinity under all ambients, but the best crystallinity was achieved in vacuum. It was revealed that the as-deposited films had the highest transmission, whereas the films annealed in air had the lowest. When annealed in air, the optical band gap decreased from 2.45 to 2.32 eV. The sheet resistance, resistivity, mobility, conductivity, and carrier concentration were measured for all the prepared V2O5 films.

Combined sonochemical/CVD method for preparation of nanostructured carbon-doped TiO{sub 2} thin film

Energy Technology Data Exchange (ETDEWEB)

Rasoulnezhad, Hossein [Semiconductor Department, Materials and Energy Research Center (MERC), Karaj (Iran, Islamic Republic of); Kavei, Ghassem, E-mail: kaveighassem@gmail.com [Semiconductor Department, Materials and Energy Research Center (MERC), Karaj (Iran, Islamic Republic of); Ahmadi, Kamran [Semiconductor Department, Materials and Energy Research Center (MERC), Karaj (Iran, Islamic Republic of); Rahimipour, Mohammad Reza [Ceramic Department, Materials and Energy Research Center (MERC), Karaj (Iran, Islamic Republic of)

2017-06-30

Highlights: • Combination of sonochemical and CVD methods for preparation of nanostructured carbon-doped TiO{sub 2} thin film on glass substrate, for the first time. • High transparency, monodispersity and homogeneity of the prepared thin films. • Preparation of the carbon-doped TiO{sub 2} thin films with nanorod and nanosphere morphologies. - Abstract: The present work reports the successful synthesis of the nanostructured carbon-doped TiO{sub 2} thin films on glass substrate by combination of chemical vapor deposition (CVD) and ultrasonic methods, for the first time. In this method the ultrasound waves act as nebulizer for converting of sonochemically prepared TiO{sub 2} sol to the mist particles. These mist particles were thermally decomposed in subsequent CVD chamber at 320 °C to produce the carbon-doped TiO{sub 2} thin films. The obtained thin films were characterized by means of X-ray Diffraction (XRD), Raman spectroscopy, diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques. The results show that the prepared thin films have anatase crystal structure and nanorod morphology, which calcination of them at 800 °C results in the conversion of nanorods to nanoparticles. In addition, the prepared samples have high transparency, monodispersity and homogeneity. The presence of the carbon element in the structure of the thin films causes the narrowing of the band-gap energy of TiO{sub 2} to about 2.8 eV, which results in the improvement of visible light absorption capabilities of the thin film.

Electrical transport properties of V2O5 thin films obtained by thermal annealing of layers grown by RF magnetron sputtering at room temperature

International Nuclear Information System (INIS)

Giannetta, H.M.R.; Calaza, C.; Lamas, D.G.; Fonseca, L.; Fraigi, L.

2015-01-01

The present study investigates the main electrical transport mechanism in V 2 O 5 thin films deposited by RF magnetron sputtering on the basis of the Mott's small polaron hopping model. The material under test was obtained at room temperature from a V 2 O 5 target and then oxidized at high temperature under air atmosphere to obtain the desired V 2 O 5 phase. The dependence of the electrical conductivity of the V 2 O 5 thin films with temperature was analyzed using the Mott's small polarons hopping transport model under the Schnakenberg form. Model results suggest a polaron binding energy W H = 0.1682 eV, with a structural disorder energy W D = 0.2241 eV and an optical phonon frequency ν 0 = 0.468 × 10 13 s −1 . These results are in agreement with data reported in literature for single crystal V 2 O 5 . However, the carrier mobility μ = 1.5019 × 10 −5 cm 2 /Vs computed in the non-adiabatic regime is significantly smaller than that of the single crystal, suggesting a strong electron–phonon coupling in the V 2 O 5 thin films obtained with the proposed deposition method. - Highlights: • A two-stage deposition method compatible with lift-off patterning is proposed. • V 2 O 5 films are deposited by RF magnetron sputtering and then annealed in air. • Films are analyzed by SEM and its pure phase nature is confirmed by XRD. • Electrical conductivity was fitted using Mott's model for small polarons. • Fit derived parameters confirm charge transport through small-polarons hopping

The optical and electrochemical properties of electrochromic films: WO3+xV2O5

Science.gov (United States)

Li, Zhuying; Liu, Hui; Liu, Ye; Yang, Shaohong; Liu, Yan; Wang, Chong

2010-05-01

Since Deb's experiment in 1973 on the electrochromic effect, transmissive electrochromic films exhibit outstanding potential as energy efficient window controls which allow dynamic control of the solar energy transmission. These films with non-volatile memory, once in the coloured state, remain in the same state even after removal of the field. The optical and electrochemical properties of electrochromic films using magnetron sputter deposition tungsten oxide thin films and vanadium oxide doped tungsten-vanadium oxide thin films on ITO coated glass were investigated. From the UV region of the transmittance spectra, the optical band gap energy from the fundamental absorption edge can be determined. And the Cyclic voltammograms of these thin films in 1 mol LiClO4 propylene carbonate electrolyte (LIPC) were measured and analysed. The anode electrochromic V2O5 doped cathode electrochromic WO3 could make films colour changing while the transmittance of films keeped invariance. These performance characteristics make tungstenvanadium oxide colour changeably thin films are suitable for electrochromic windows applications.

Synthesis and photocatalytic properties of porous TiO2 films prepared by ODA/sol-gel method

International Nuclear Information System (INIS)

Zhang Wenjie; Bai Jiawei

2012-01-01

Porous TiO 2 films were deposited on SiO 2 pre-coated glass-slides by sol-gel method using octadecylamine (ODA) as template. The amount of ODA in the sol played an important role on the physicochemical properties and photocatalytic performance of the TiO 2 films. The films prepared at different conditions were all composed of anatase titanium dioxide crystals, and TiO 2 crystalline size got larger with increasing ODA amount. The maximum specific surface area of 41.5 m 2 /g was obtained for TiO 2 powders prepared from titanium sol containing 2.0 g ODA. Methyl orange degradation rate was enhanced along with increasing ODA amount and reached the maximal value at 2.0 g addition of ODA. After 40 min of UV-light irradiation, methyl orange degradation rate reached 30.5% on the porous film, which was about 10% higher than that on the smooth film. Porous TiO 2 film showed almost constant activity with slight decrease from 30.5% to 28.5% after 4 times of recycles.

Thickness Measurement of V2O5 Nanometric Thin Films Using a Portable XRF

Directory of Open Access Journals (Sweden)

Fabio Lopes

2016-01-01

Full Text Available Nanometric thin films have always been chiefly used for decoration; however they are now being widely used as the basis of high technology. Among the various physical qualities that characterize them, the thickness strongly influences their properties. Thus, a new procedure is hereby proposed and developed for determining the thickness of V2O5 nanometric thin films deposited on the glass surface using Portable X-Ray Fluorescence (PXRF equipment and the attenuation of the radiation intensity Kα of calcium present in the glass. It is shown through the present paper that the radiation intensity of calcium Kα rays is proportional to film thickness in nanometric films of vanadium deposited on the glass surface.

Thickness-dependence of optical constants for Ta2O5 ultrathin films

International Nuclear Information System (INIS)

Zhang, Dong-Xu; Zheng, Yu-Xiang; Cai, Qing-Yuan; Lin, Wei; Wu, Kang-Ning; Mao, Peng-Hui; Zhang, Rong-Jun; Zhao, Hai-bin; Chen, Liang-Yao

2012-01-01

An effective method for determining the optical constants of Ta 2 O 5 thin films deposited on crystal silicon (c-Si) using spectroscopic ellipsometry (SE) measurement with a two-film model (ambient-oxide-interlayer-substrate) was presented. Ta 2 O 5 thin films with thickness range of 1-400 nm have been prepared by the electron beam evaporation (EBE) method. We find that the refractive indices of Ta 2 O 5 ultrathin films less than 40 nm drop with the decreasing thickness, while the other ones are close to those of bulk Ta 2 O 5 . This phenomenon was due to the existence of an interfacial oxide region and the surface roughness of the film, which was confirmed by the measurement of atomic force microscopy (AFM). Optical properties of ultrathin film varying with the thickness are useful for the design and manufacture of nano-scaled thin-film devices. (orig.)

Thickness-dependence of optical constants for Ta2O5 ultrathin films

Science.gov (United States)

Zhang, Dong-Xu; Zheng, Yu-Xiang; Cai, Qing-Yuan; Lin, Wei; Wu, Kang-Ning; Mao, Peng-Hui; Zhang, Rong-Jun; Zhao, Hai-bin; Chen, Liang-Yao

2012-09-01

An effective method for determining the optical constants of Ta2O5 thin films deposited on crystal silicon (c-Si) using spectroscopic ellipsometry (SE) measurement with a two-film model (ambient-oxide-interlayer-substrate) was presented. Ta2O5 thin films with thickness range of 1-400 nm have been prepared by the electron beam evaporation (EBE) method. We find that the refractive indices of Ta2O5 ultrathin films less than 40 nm drop with the decreasing thickness, while the other ones are close to those of bulk Ta2O5. This phenomenon was due to the existence of an interfacial oxide region and the surface roughness of the film, which was confirmed by the measurement of atomic force microscopy (AFM). Optical properties of ultrathin film varying with the thickness are useful for the design and manufacture of nano-scaled thin-film devices.

Thermoreflectance characterization of beta-Ga2O3 thin-film nanostrips.

Science.gov (United States)

Ho, Ching-Hwa; Tseng, Chiao-Yeh; Tien, Li-Chia

2010-08-02

Nanostructure of beta-Ga(2)O(3) is wide-band-gap material with white-light-emission function because of its abundance in gap states. In this study, the gap states and near-band-edge transitions in beta-Ga(2)O(3) nanostrips have been characterized using temperature-dependent thermoreflectance (TR) measurements in the temperature range between 30 and 320 K. Photoluminescence (PL) measurements were carried to identify the gap-state transitions in the beta-Ga(2)O(3) nanostrips. Experimental analysis of the TR spectra revealed that the direct gap (E(0)) of beta-Ga(2)O(3) is 4.656 eV at 300 K. There are a lot of gap-state and near-band-edge (GSNBE) transitions denoted as E(D3), E(W1), E(W2), E(W3), E(D2), EDBex, E(DB), E(D1), E(0), and E(0)' can be detected in the TR and PL spectra at 30 K. Transition origins for the GSNBE features in the beta-Ga(2)O(3) nanostrips are respectively evaluated. Temperature dependences of transition energies of the GSNBE transitions in the beta-Ga(2)O(3) nanostrips are analyzed. The probable band scheme for the GSNBE transitions in the beta-Ga(2)O(3) nanostrips is constructed.

Microstructure and optical properties of nanocrystalline Cu2O thin films prepared by electrodeposition.

Science.gov (United States)

Jiang, Xishun; Zhang, Miao; Shi, Shiwei; He, Gang; Song, Xueping; Sun, Zhaoqi

2014-01-01

Cuprous oxide (Cu2O) thin films were prepared by using electrodeposition technique at different applied potentials (-0.1, -0.3, -0.5, -0.7, and -0.9 V) and were annealed in vacuum at a temperature of 100°C for 1 h. Microstructure and optical properties of these films have been investigated by X-ray diffractometer (XRD), field-emission scanning electron microscope (SEM), UV-visible (vis) spectrophotometer, and fluorescence spectrophotometer. The morphology of these films varies obviously at different applied potentials. Analyses from these characterizations have confirmed that these films are composed of regular, well-faceted, polyhedral crystallites. UV-vis absorption spectra measurements have shown apparent shift in optical band gap from 1.69 to 2.03 eV as the applied potential becomes more cathodic. The emission of FL spectra at 603 nm may be assigned as the near band-edge emission.

Preparation and properties of KCl-doped Cu2O thin film by electrodeposition

International Nuclear Information System (INIS)

Yu, Xiaojiao; Li, Xinming; Zheng, Gang; Wei, Yuchen; Zhang, Ama; Yao, Binghua

2013-01-01

With the indium tin oxide-coated glass as working electrode, cuprous oxide thin film is fabricated by means of electrodeposition. The effects of KCl doped and annealing treatment upon Cu 2 O thin film morphology, surface resistivity, open-circuit voltage, electric conduction types and visible light response are studied. The research results indicate that KCl doped has a great effect upon Cu 2 O crystal morphology, thus, making Cu 2 O thin film surface resistivity drop, and the open-circuit voltage increase and that electric conduction types are transformed from p type into n type, and the visible light (400–500 nm) absorption rate is slightly reduced. Annealing treatment can obviously decrease Cu 2 O thin film surface resistivity and improve its open-circuit voltage. When KCl concentration in electrolytic solution reaches 7 mmol/L, Cu 2 O thin film morphology can be changed from the dendritic crystal into the cubic crystal and Cu 2 O thin film surface resistivity decreases from the initial 2.5 × 10 6 Ω cm to 8.5 × 10 4 Ω cm. After annealing treatment at 320 °C for 30 min, the surface resistivity decreases to 8.5 × 10 2 Ω cm, and the open-circuit voltage increases from the initial 3.1 mV to 79.2 mV.

Determination of structural, mechanical and corrosion properties of Nb{sub 2}O{sub 5} and (Nb{sub y}Cu{sub 1−y})O{sub x} thin films deposited on Ti6Al4V alloy substrates for dental implant applications

Energy Technology Data Exchange (ETDEWEB)

Mazur, M. [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland); Kalisz, M., E-mail: malgorzata.kalisz@its.waw.pl [Motor Transport Institute, Jagiellońska 80, 03-301 Warsaw (Poland); Wojcieszak, D. [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland); Grobelny, M. [Motor Transport Institute, Jagiellońska 80, 03-301 Warsaw (Poland); Mazur, P. [Wroclaw University, Institute of Experimental Physics, Max Born 9, 50-204 Wroclaw (Poland); Kaczmarek, D.; Domaradzki, J. [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland)

2015-02-01

In this paper comparative studies on the structural, mechanical and corrosion properties of Nb{sub 2}O{sub 5}/Ti and (Nb{sub y}Cu{sub 1−y})O{sub x}/Ti alloy systems have been investigated. Pure layers of niobia and niobia with a copper addition were deposited on a Ti6Al4V titanium alloy surface using the magnetron sputtering method. The physicochemical properties of the prepared thin films were examined with the aid of XRD, XPS SEM and AFM measurements. The mechanical properties (i.e., nanohardness, Young's modulus and abrasion resistance) were performed using nanoindentation and a steel wool test. The corrosion properties of the coatings were determined by analysis of the voltammetric curves. The deposited coatings were crack free, exhibited good adherence to the substrate, no discontinuity of the thin film was observed and the surface morphology was homogeneous. The hardness of pure niobium pentoxide was ca. 8.64 GPa. The obtained results showed that the addition of copper into pure niobia resulted in the preparation of a layer with a lower hardness of ca. 7.79 GPa (for niobia with 17 at.% Cu) and 7.75 GPa (for niobia with 25 at.% Cu). The corrosion properties of the tested thin films deposited on the surface of titanium alloy depended on the composition of the thin layer. The addition of copper (i.e. a noble metal) to Nb{sub 2}O{sub 5} film increased the corrosion resistance followed by a significant decrease in the value of corrosion currents and, in case of the highest Cu content, the shift of corrosion potential towards the noble direction. The best corrosion properties were obtained from a sample of Ti6Al4V coated with (Nb{sub 0.75}Cu{sub 0.25})O{sub x} thin film. It seems that the tested materials could be used in the future as protection coatings for Ti alloys in biomedical applications such as implants. - Highlights: • Nb{sub 2}O{sub 5} and Nb{sub 2}O{sub 5}:Cu thin films were deposited on a Ti–Al–V surface using the magnetron sputtering. �

Influence of solution deposition rate on properties of V{sub 2}O{sub 5} thin films deposited by spray pyrolysis technique

Energy Technology Data Exchange (ETDEWEB)

Abd–Alghafour, N. M., E-mail: na2013bil@gmail.com [Iraqi Ministry of Education, Anbar (Iraq); Ahmed, Naser M.; Hassan, Zai; Mohammad, Sabah M. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, University Sains Malaysia,11800 Penang (Malaysia)

2016-07-19

Vanadium oxide (V{sub 2}O{sub 5}) thin films were deposited on glass substrates by using a cost-efficient spray pyrolysis technique. The films were grown at 350° through thermal decomposition of VCl{sub 3} in deionized water with different solution spray rates. The high resolution X-ray diffraction results revealed the formation of nanocrystalline films having orthorhombic structures with preferential orientation along (101) direction. The spray rate influenced the surface morphology and crystallite size of the films. The crystallite size was found to increase whereas the micro-strain was decreased by increasing the spray deposition rates. The increase in crystallite size and decrease in the macrostrain resulted in an improvement in the films’ crystallinity. The UV-Visible spectroscopy analysis indicated that the average transmittance of all films lies in the range 75-80 %. The band gap of V{sub 2}O{sub 5} film was decreased from 2.65 to 2.46 eV with increase of the spray deposition rate from 5 ml/min to 10 ml/min. first, second, and third level headings (first level heading).

Enhancement of photoelectric catalytic activity of TiO2 film via Polyaniline hybridization

International Nuclear Information System (INIS)

Wang Yajun; Xu Jing; Zong Weizheng; Zhu Yongfa

2011-01-01

A Polyaniline (PANI)/TiO 2 film coated on titanium foil was successfully prepared using the sol-gel method followed by a facile chemisorption. Compared with pristine TiO 2 , the photocatalytic (PC) and photoelectrocatalytic (PEC) degradation rates of 2,4-dichlorophenol (2,4-DCP) with the PANI/TiO 2 film were enhanced by 22.2% and 57.5%, respectively. 2,4-DCP can be mineralized more effectively in the presence of PANI/TiO 2 film. The best PEC degradation efficiency of 2,4-DCP with the PANI/TiO 2 film was acquired at an external potential of 1.5 V with a layer of 1 nm thick PANI. The PANI/TiO 2 film was characterized by Raman spectra, Fourier transform infrared spectra (FT-IR), Auger electron spectroscopy (AES), and electrochemical analysis. These results indicated that there was a chemical interaction on the interface of PANI and TiO 2 . This interaction may be of significance to promote the migration efficiency of carriers and induce a synergetic effect to enhance the PC and PEC activities. - Graphical abstract: The effect of PANI content on 2,4-DCP degradation with initial concentration of 50 mg/L, external potential=1.5 V. Inset: degradation rate constants of various PANI/TiO 2 films. Highlights: → Polyaniline/TiO 2 film was prepared using the sol-gel method followed by chemisorption. → Photoelectrocatalytic degradation rate of 2,4-dichlorophenol was enhanced by 57.5%. → The modification of Polyaniline to TiO 2 film caused a rapid charge separation. → Best degradation efficiency was acquired at 1.5 V with 1 nm thick PANI.

Preparation of anatase TiO2 thin films by vacuum arc plasma evaporation

International Nuclear Information System (INIS)

Miyata, Toshihiro; Tsukada, Satoshi; Minami, Tadatsugu

2006-01-01

Anatase titanium dioxide (TiO 2 ) thin films with high photocatalytic activity have been prepared with deposition rates as high as 16 nm/min by a newly developed vacuum arc plasma evaporation (VAPE) method using sintered TiO 2 pellets as the source material. Highly transparent TiO 2 thin films prepared at substrate temperatures from room temperature to 400 deg. C exhibited photocatalytic activity, regardless whether oxygen (O 2 ) gas was introduced during the VAPE deposition. The highest photocatalytic activity and photo-induced hydrophilicity were obtained in anatase TiO 2 thin films prepared at 300 deg. C, which correlated to the best crystallinity of the films, as evidenced from X-ray diffraction. In addition, a transparent and conductive anatase TiO 2 thin film with a resistivity of 2.6 x 10 -1 Ω cm was prepared at a substrate temperature of 400 deg. C without the introduction of O 2 gas

All solid-state V2O5-based flexible hybrid fiber supercapacitors

Science.gov (United States)

Li, Huan; He, Jin; Cao, Xin; Kang, Liping; He, Xuexia; Xu, Hua; Shi, Feng; Jiang, Ruibin; Lei, Zhibin; Liu, Zong-Huai

2017-12-01

Vanadium pentoxide/single-walled carbon nanotube (V2O5-SWCNT) hybrid fibers with good electrochemical performance and flexibility are firstly prepared by using wet-spinning method. V2O5 nanobelt suspension is obtained by mixing V2O5 bulk, 30% H2O2, H2O and followed by hydrothermally treating at 190 °C for 15 h. SWCNT suspension is suspended into V2O5 nanobelt suspension under vigorous stirring, the V2O5-SWCNT homogenous suspension is obtained. It is injected into a coagulation bath composed of 5 wt % CaCl2 ethanol-water solution using syringe pump, V2O5-SWCNT hybrid fibers are prepared by washing with deionized water and drying at room temperature. Reduced graphene oxide (RGO)-SWCNT hybrid fibers are also prepared by the similar wet-spinning approach and followed by reducing GO-SWCNT hybrid fibers in an aqueous solution of hydriodic acid. All solid-state asymmetric V2O5/SWCNT//RGO/SWCNT fiber supercapacitors are assembled with V2O5-SWCNT fiber as positive electrode and RGO-SWCNT fiber as negative electrode by using PVA-H3PO4 as gel electrolyte. The assembled device not only shows maximum volumetric energy density of 1.95 mW h cm-3 at a volumetric power density of 7.5 mW cm-3, superior rate performance and cycling stability, but also exhibits remarkable flexibility to tolerate long-term and repeated bending. This work will open a new application filed of V2O5-based fibers in wearable energy storage devices.

Sol-gel prepared B2O3-SiO2 thin films for protection of copper substrates

International Nuclear Information System (INIS)

Gouda, M.; Ahmed, M.S.; Shahin, M.A.

2000-01-01

Full text.Borosilicate coating has potential for applications in the field of electronics, e.g., as passivation layers. One of the main difficulties for applying these films by the conventional melting process is the extensive volatilization of B 2 O 3 from the melt. In this work transparent borosilicate films of 2OB 2 O3.8OSiO 2 (in mole %). Prepared by the sole gel method, were applied onto copper substrates by dip-coating technique. The transparency of these films was very sensitive to the humidity of the atmosphere during the coating process. Transparent films were obtained below 20% relative humidity at 20 celsius degree. High temperature oxidation tests, at about 585 celsius degree stream of air, showed that the sol-gel prepared 2OB 2 O 3 .8OSiO 2 thin films are protective coating for copper substrates under fairly severe temperature gradient and oxidizing atmosphere. It was found that the protective action of these films depends on the film thickness

Effects of MeV Si ions bombardment on the thermoelectric generator from SiO{sub 2}/SiO{sub 2} + Cu and SiO{sub 2}/SiO{sub 2} + Au nanolayered multilayer films

Energy Technology Data Exchange (ETDEWEB)

Budak, S., E-mail: satilmis.budak@aamu.edu [Department of Electrical Engineering, Alabama A and M University, Normal, AL (United States); Chacha, J., E-mail: chacha_john79@hotmail.com [Department of Electrical Engineering, Alabama A and M University, Normal, AL (United States); Smith, C., E-mail: cydale@cim.aamu.edu [Center for Irradiation of Materials, Alabama A and M University, Normal, AL (United States); Department of Physics, Alabama A and M University, Normal, AL (United States); Pugh, M., E-mail: marcuspughp@yahoo.com [Department of Electrical Engineering, Alabama A and M University, Normal, AL (United States); Colon, T. [Department of Mechanical Engineering, Alabama A and M University, Normal, AL (United States); Heidary, K., E-mail: kaveh.heidary@aamu.edu [Department of Electrical Engineering, Alabama A and M University, Normal, AL (United States); Johnson, R.B., E-mail: barry@w4wb.com [Department of Physics, Alabama A and M University, Normal, AL (United States); Ila, D., E-mail: ila@cim.aamu.edu [Center for Irradiation of Materials, Alabama A and M University, Normal, AL (United States); Department of Physics, Alabama A and M University, Normal, AL (United States)

2011-12-15

The defects and disorder in the thin films caused by MeV ions bombardment and the grain boundaries of these nanoscale clusters increase phonon scattering and increase the chance of an inelastic interaction and phonon annihilation. We prepared the thermoelectric generator devices from 100 alternating layers of SiO{sub 2}/SiO{sub 2} + Cu multi-nano layered superlattice films at the total thickness of 382 nm and 50 alternating layers of SiO{sub 2}/SiO{sub 2} + Au multi-nano layered superlattice films at the total thickness of 147 nm using the physical vapor deposition (PVD). Rutherford Backscattering Spectrometry (RBS) and RUMP simulation have been used to determine the stoichiometry of the elements of SiO{sub 2}, Cu and Au in the multilayer films and the thickness of the grown multi-layer films. The 5 MeV Si ions bombardments have been performed using the AAMU-Center for Irradiation of Materials (CIM) Pelletron ion beam accelerator to make quantum (nano) dots and/or quantum (quantum) clusters in the multilayered superlattice thin films to decrease the cross plane thermal conductivity, increase the cross plane Seebeck coefficient and cross plane electrical conductivity. To characterize the thermoelectric generator devices before and after Si ion bombardments we have measured Seebeck coefficient, cross-plane electrical conductivity, and thermal conductivity in the cross-plane geometry for different fluences.

Preparation of TiO{sub 2}/boron-doped diamond/Ta multilayer films and use as electrode materials for supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Shi, Chao, E-mail: sc_sq1988@163.com [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China); Li, Hongji, E-mail: hongjili@yeah.net [Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384 (China); Li, Cuiping, E-mail: licp226@126.com [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China); Li, Mingji, E-mail: limingji@163.com [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China); Qu, Changqing, E-mail: quchangqing@tjut.edu.cn [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China); Yang, Baohe, E-mail: bhyang207@163.com [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China)

2015-12-01

Highlights: • BDD film was deposited on Ta substrate by hot filament CVD method. • Ti layer was deposited on BDD film by radio frequency magnetron sputtering. • Nanostructured TiO{sub 2}/BDD/nanoporous Ta films were prepared. • The films exhibit good capacitance performance and excellent stability. - Abstract: We report nanostructured TiO{sub 2}/boron-doped diamond (BDD)/Ta multilayer films and their electrochemical performances as supercapacitor electrodes. The BDD films were grown on Ta substrates using electron-assisted hot filament chemical vapor deposition. Ti metal layers were deposited on the BDD surfaces by radio frequency magnetron sputtering, and nanostructured TiO{sub 2}/BDD/Ta thin films were prepared by electrochemical etching and thermal annealing. The successful formation of TiO{sub 2} and Ta layered nanostructures was demonstrated using scanning electron and transmission electron microscopies. The electrochemical responses of these electrodes were evaluated by examining their use as electrical double-layer capacitors, using cyclic voltammetry, and galvanostatic charge/discharge and impedance measurements. When the TiO{sub 2}/BDD/Ta film was used as the working electrode with 0.1 M Na{sub 2}SO{sub 4} as the electrolyte, the capacitor had a specific capacitance of 5.23 mF cm{sup −2} at a scan rate of 5 mV s{sup −1} for a B/C ratio of 0.1% w/w. Furthermore, the TiO{sub 2}/BDD/Ta film had improved electrochemical stability, with a retention of 89.3% after 500 cycles. This electrochemical behavior is attributed to the quality of the BDD, the surface roughness and electrocatalytic activities of the TiO{sub 2} layer and Ta nanoporous structures, and the synergies between them. These results show that TiO{sub 2}/BDD/Ta films are promising as capacitor electrodes for special applications.

Optical characterization of {beta}-FeSi{sub 2} thin films prepared on fused quartz by femtosecond laser

Energy Technology Data Exchange (ETDEWEB)

Zhou Youhua [Wuhan National Laboratory for Optoelectronics and School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Physics and Information Engineering, Jianghan University, Wuhan 430056 (China); Lu Peixiang [Wuhan National Laboratory for Optoelectronics and School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)]. E-mail: lupeixiang@mail.hust.edu.cn; Yang Guang [Wuhan National Laboratory for Optoelectronics and School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Long Hua [Wuhan National Laboratory for Optoelectronics and School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zheng Qiguang [Wuhan National Laboratory for Optoelectronics and School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

2007-10-01

Single-phase {beta}-FeSi{sub 2} thin films have been grown on quartz substrates using femtosecond laser deposition (800 nm, 50 fs, 1 kHz) under gas pressure of 3.0x10{sup -4} Pa. X-ray diffraction (XRD) and field-emission scanning electron microscopy (SEM) were used to determine the structural properties and surface images of the films. Typical XRD patterns of the film showed that no other diffraction peak except {beta}-FeSi{sub 2} was found. The SEM results indicated that the films were composed of well-distributed grains, in the range 50-150 nm in diameter. In addition, normal incidence spectral transmittance and reflectance data suggested that the {beta}-FeSi{sub 2} film has a direct energy gap of about 0.85 eV. The thickness of the layer and the refractive index of the film were determined by performed calculation in the wavelength range 1.9-2.7 {mu}m. Furthermore, the Raman spectra of the films were also discussed.

Preparation and properties of KCl-doped Cu{sub 2}O thin film by electrodeposition

Energy Technology Data Exchange (ETDEWEB)

Yu, Xiaojiao, E-mail: yxjw@xaut.edu.cn [Xi’an University of Technology, Xi’an 710048 (China); Li, Xinming [Xi’an University of Technology, Xi’an 710048 (China); Zheng, Gang [Xi’an University of Technology, Xi’an 710048 (China); Northwestern Polytechnical University, Xi’an 710072 (China); Wei, Yuchen [The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China); Zhang, Ama; Yao, Binghua [Xi’an University of Technology, Xi’an 710048 (China)

2013-04-01

With the indium tin oxide-coated glass as working electrode, cuprous oxide thin film is fabricated by means of electrodeposition. The effects of KCl doped and annealing treatment upon Cu{sub 2}O thin film morphology, surface resistivity, open-circuit voltage, electric conduction types and visible light response are studied. The research results indicate that KCl doped has a great effect upon Cu{sub 2}O crystal morphology, thus, making Cu{sub 2}O thin film surface resistivity drop, and the open-circuit voltage increase and that electric conduction types are transformed from p type into n type, and the visible light (400–500 nm) absorption rate is slightly reduced. Annealing treatment can obviously decrease Cu{sub 2}O thin film surface resistivity and improve its open-circuit voltage. When KCl concentration in electrolytic solution reaches 7 mmol/L, Cu{sub 2}O thin film morphology can be changed from the dendritic crystal into the cubic crystal and Cu{sub 2}O thin film surface resistivity decreases from the initial 2.5 × 10{sup 6} Ω cm to 8.5 × 10{sup 4} Ω cm. After annealing treatment at 320 °C for 30 min, the surface resistivity decreases to 8.5 × 10{sup 2} Ω cm, and the open-circuit voltage increases from the initial 3.1 mV to 79.2 mV.

Electrical transport properties of V{sub 2}O{sub 5} thin films obtained by thermal annealing of layers grown by RF magnetron sputtering at room temperature

Energy Technology Data Exchange (ETDEWEB)

Giannetta, H.M.R., E-mail: hgiann@inti.gov.ar [Centro de Micro y Nano Electrónica del Bicentenario (CMNB), Instituto Nacional de Tecnología Industrial (INTI), San Martín, Buenos Aires (Argentina); Universidad Tecnológica Nacional (UTN) — Facultad Regional Buenos Aires (FRBA) (Argentina); Calaza, C. [Instituto de Microelectrónica de Barcelona, Centro Nacional de Microelectrónica (IMB-CNM, CSIC), Campus UAB, Bellaterra, 08193 Barcelona (Spain); Lamas, D.G. [Universidad Nacional del Comahue CONICET-CITEFA — Laboratorio de Caracterización de Materiales, Facultad de Ingeniería, Neuquen (Argentina); Fonseca, L. [Instituto de Microelectrónica de Barcelona, Centro Nacional de Microelectrónica (IMB-CNM, CSIC), Campus UAB, Bellaterra, 08193 Barcelona (Spain); Fraigi, L. [Centro de Micro y Nano Electrónica del Bicentenario (CMNB), Instituto Nacional de Tecnología Industrial (INTI), San Martín, Buenos Aires (Argentina); Universidad Tecnológica Nacional (UTN) — Facultad Regional Buenos Aires (FRBA) (Argentina)

2015-08-31

The present study investigates the main electrical transport mechanism in V{sub 2}O{sub 5} thin films deposited by RF magnetron sputtering on the basis of the Mott's small polaron hopping model. The material under test was obtained at room temperature from a V{sub 2}O{sub 5} target and then oxidized at high temperature under air atmosphere to obtain the desired V{sub 2}O{sub 5} phase. The dependence of the electrical conductivity of the V{sub 2}O{sub 5} thin films with temperature was analyzed using the Mott's small polarons hopping transport model under the Schnakenberg form. Model results suggest a polaron binding energy W{sub H} = 0.1682 eV, with a structural disorder energy W{sub D} = 0.2241 eV and an optical phonon frequency ν{sub 0} = 0.468 × 10{sup 13}s{sup −1}. These results are in agreement with data reported in literature for single crystal V{sub 2}O{sub 5}. However, the carrier mobility μ = 1.5019 × 10{sup −5} cm{sup 2}/Vs computed in the non-adiabatic regime is significantly smaller than that of the single crystal, suggesting a strong electron–phonon coupling in the V{sub 2}O{sub 5} thin films obtained with the proposed deposition method. - Highlights: • A two-stage deposition method compatible with lift-off patterning is proposed. • V{sub 2}O{sub 5} films are deposited by RF magnetron sputtering and then annealed in air. • Films are analyzed by SEM and its pure phase nature is confirmed by XRD. • Electrical conductivity was fitted using Mott's model for small polarons. • Fit derived parameters confirm charge transport through small-polarons hopping.

Excimer laser processing of ZnO thin films prepared by the sol-gel process

International Nuclear Information System (INIS)

Winfield, R.J.; Koh, L.H.K.; O'Brien, Shane; Crean, Gabriel M.

2007-01-01

ZnO thin films were prepared on soda-lime glass from a single spin-coating deposition of a sol-gel prepared with anhydrous zinc acetate [Zn(C 2 H 3 O 2 ) 2 ], monoethanolamine [H 2 NC 2 H 4 OH] and isopropanol. The deposited films were dried at 50 and 300 deg. C. X-ray analysis showed that the films were amorphous. Laser annealing was performed using an excimer laser. The laser pulse repetition rate was 25 Hz with a pulse energy of 5.9 mJ, giving a fluence of 225 mJ cm -2 on the ZnO film. Typically, five laser pulses per unit area of the film were used. After laser processing, the hexagonal wurtzite phase of zinc oxide was observed from X-ray diffraction pattern analysis. The thin films had a transparency of greater than 70% in the visible region. The optical band-gap energy was 3.454 eV. Scanning electron microscopy and profilometry analysis highlighted the change in morphology that occurred as a result of laser processing. This comparative study shows that our sol-gel processing route differs significantly from ZnO sol-gel films prepared by conventional furnace annealing which requires temperatures above 450 deg. C for the formation of crystalline ZnO

Superconducting Tl2Ba2CaCu2O8 thin films prepared by post-annealing in a flow-through multiple-zone furnace

International Nuclear Information System (INIS)

Pluym, T.C.; Muenchausen, R.E.; Arendt, P.N.

1994-01-01

Tl 2 Ba 2 CaCu 2 O 8 thin films were prepared for the first time by use of a multiple-zone flow-through thallination process. Thallous oxide was volatilized from condensed thallium oxide in a low temperature source zone and convectively transported to a higher temperature thallination zone in which initially amorphous Ba 2 CaCu 2 O 5 precursor films were located. By careful control of the source temperature, film temperature, flow rate, anneal time, and rates of heat up and cool down, smooth Tl 2 Ba 2 CaCu 2 O 8 thin films were prepared on (100) LaAlO 3 with the following properties: inductive T c of 107.6 K and 80% transition width of 1.3 K, transport J c at 75 K of 1.3 x 10 5 A/cm 2 , and R s at 10 GHz and 80 K of 1.3 mΩ. The scalability of the process to large area film processing was demonstrated by the preparation of Tl 2 Ba 2 CaCu 2 O 8 thin films on LaAlO 3 three-inch diameter wafers

Preparation of anatase TiO{sub 2} thin films by vacuum arc plasma evaporation

Energy Technology Data Exchange (ETDEWEB)

Miyata, Toshihiro [Optoelectronic Device System R and D Center, Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichi, Ishikawa 921-8501 (Japan)]. E-mail: tmiyata@neptune.kanazawa-it.ac.jp; Tsukada, Satoshi [Optoelectronic Device System R and D Center, Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichi, Ishikawa 921-8501 (Japan); Minami, Tadatsugu [Optoelectronic Device System R and D Center, Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichi, Ishikawa 921-8501 (Japan)

2006-02-01

Anatase titanium dioxide (TiO{sub 2}) thin films with high photocatalytic activity have been prepared with deposition rates as high as 16 nm/min by a newly developed vacuum arc plasma evaporation (VAPE) method using sintered TiO{sub 2} pellets as the source material. Highly transparent TiO{sub 2} thin films prepared at substrate temperatures from room temperature to 400 deg. C exhibited photocatalytic activity, regardless whether oxygen (O{sub 2}) gas was introduced during the VAPE deposition. The highest photocatalytic activity and photo-induced hydrophilicity were obtained in anatase TiO{sub 2} thin films prepared at 300 deg. C, which correlated to the best crystallinity of the films, as evidenced from X-ray diffraction. In addition, a transparent and conductive anatase TiO{sub 2} thin film with a resistivity of 2.6 x 10{sup -1} {omega} cm was prepared at a substrate temperature of 400 deg. C without the introduction of O{sub 2} gas.

Characteristics of TiO_2/ZnO bilayer film towards pH sensitivity prepared by different spin coating deposition process

International Nuclear Information System (INIS)

Rahman, Rohanieza Abdul; Zulkefle, Muhammad Al Hadi; Abdullah, Wan Fazlida Hanim; Rusop, M.; Herman, Sukreen Hana

2016-01-01

In this study, titanium dioxide (TiO_2) and zinc oxide (ZnO) bilayer film for pH sensing application will be presented. TiO_2/ZnO bilayer film with different speed of spin-coating process was deposited on Indium Tin Oxide (ITO), prepared by sol-gel method. This fabricated bilayer film was used as sensing membrane for Extended Gate Field-Effect Transistor (EGFET) for pH sensing application. Experimental results indicated that the sensor is able to detect the sensitivity towards pH buffer solution. In order to obtained the result, sensitivity measurement was done by using the EGFET setup equipment with constant-current (100 µA) and constant-voltage (0.3 V) biasing interfacing circuit. TiO_2/ZnO bilayer film which the working electrode, act as the pH-sensitive membrane was connected to a commercial metal-oxide semiconductor FET (MOSFET). This MOSFET then was connected to the interfacing circuit. The sensitivity of the TiO2 thin film towards pH buffer solution was measured by dipping the sensing membrane in pH4, pH7 and pH10 buffer solution. These thin films were characterized by using Field Emission Scanning Electron Microscope (FESEM) to obtain the surface morphology of the composite bilayer films. In addition, I-V measurement was done in order to determine the electrical properties of the bilayer films. According to the result obtained in this experiment, bilayer film that spin at 4000 rpm, gave highest sensitivity which is 52.1 mV/pH. Relating the I-V characteristic of the thin films and sensitivity, the sensing membrane with higher conductivity gave better sensitivity.

MnV2O6.V2O5 cross-like nanobelt arrays: synthesis, characterization and photocatalytic properties

International Nuclear Information System (INIS)

Abbood, Hayder A.; Ahmed, Khalid Abdelazez Mohamed; Ren, Yong; Huang, Kaixun

2013-01-01

Single-crystalline MnV 2 O 6 .V 2 O 5 cross-like nanobelt arrays were successfully synthesized by hydrothermal reaction. The products were characterized by X-ray diffraction, transmission electron microscopy and high-resolution transmission electron microscopy. The effects of the reaction conditions such as pH, V 5+ /Mn 2+ ratio, carboxymethyl cellulose concentration and reaction time on the morphology of the products were studied. The band gap of the as-prepared products was calculated via diffuse reflectance spectral analysis and their activity of photocatalytic oxidation was evaluated by photodegradation of methylene blue under visible-light irradiation. The results showed that the degradation efficiency of methylene blue catalyzed by the calcinated products is remarkably enhanced due to Mn doping, suggesting that MnV 2 O 6 .V 2 O 5 cross-like nanobelt arrays are a good candidate for visible-light-driven photocatalysts. (orig.)

Preparation and characterization of nanocrystalline porous TiO2/WO3 composite thin films

International Nuclear Information System (INIS)

Hsu, C.-S.; Lin, C.-K.; Chan, C.-C.; Chang, C.-C.; Tsay, C.-Y.

2006-01-01

TiO 2 materials possessing not only photocatalytic but also electrochromic properties have attracted many research and development interests. Though WO 3 exhibits excellent electrochromic properties, the much higher cost and water-sensitivity of WO 3 as compared with the TiO 2 may restrict the practical application of WO 3 materials. In the present study, the feasibility of preparing nanocrystalline porous TiO 2 /WO 3 composite thin films was investigated. Precursors of sols TiO 2 and/or WO 3 and polystyrene microspheres were used to prepare nanocrystalline pure TiO 2 , WO 3 , and composite TiO 2 /WO 3 thin films by spin coating. The spin-coated thin films were amorphous and, after heat treating at a temperature of 500 o C, nanocrystalline TiO 2 , TiO 2 /WO 3 , and WO 3 thin films with or without pores were prepared successfully. The heat-treated thin films were colorless and coloration-bleaching phenomena can be observed during cyclic voltammetry tests. The heat-treated thin films exhibited good reversible electrochromic behavior while the porous TiO 2 /WO 3 composite film exhibited improved electrochromic properties

Sequential Ar-O2 sputtering of Y2O3, BaF2, and CuO targets for preparation of Y-Ba-Cu-O superconducting films without wet-O2 annealing

International Nuclear Information System (INIS)

Bhushan, M.; Strauss, A.J.; Finn, M.C.

1989-01-01

Superconducting Y-Ba-Cu-O (YBCO) films have been prepared by ex situ O 2 annealing of multilayer films deposited on yttria-stabilized zirconia substrates by sequential rf diode sputtering of Y 2 O 3 , BaF 2 , and CuO targets, all of which are chemically stable. If sputtering is performed in an Ar ambient, the as-deposited films contain sufficient F to require its removal by annealing in wet O 2 at about 800 degree C or above before the superconducting YBCO phase can be formed by annealing in dry O 2 . However, sputtering in an Ar-O 2 ambient greatly reduces the F content, making it possible to obtain the superconducting phase by annealing in dry O 2 only. If the ambient contains about 20% O 2 , films with T c (R=0)>85 K can be prepared without wet-O 2 annealing. The Ar-O 2 process therefore has the potential for in situ preparation of superconducting YBCO films

Transparent conductive Ta2O5-codoped ITO thin films prepared by different heating process

International Nuclear Information System (INIS)

Zhang, B.; Dong, X.P.; Wu, J.S.; Xu, X.F.

2008-01-01

Tantalum-doped indium tin oxide thin films were deposited by a cosputtering technique with an ITO target and a Ta 2 O 5 target. The variations of microstructure, electrical and optical properties with substrate temperature and annealing temperature were investigated in some detail. Ta-doped ITO thin films showed better crystalline structure with different prominent plane orientation by different heating process. ITO:Ta thin films deposited at room temperature showed better optical and electrical properties. Increasing substrate temperature and reasonable annealing temperature could remarkably improve the optical and electrical properties of the films. The variation of carrier concentration had an important influence on near-IR reflection, near-UV absorption and optical bandgap. ITO:Ta thin films showed wider optical bandgap. ITO:Ta thin films under the optimum parameters had a sheet resistance of 10-20 and ohm;/sq and a transmittance of 85% with an optical bandgap of above 4.0 eV. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Preparation of Porous F-WO3/TiO2 Films with Visible-Light Photocatalytic Activity by Microarc Oxidation

OpenAIRE

Yeh, Chung-Wei; Wu, Kee-Rong; Hung, Chung-Hsuang; Chang, Hao-Cheng; Hsu, Chuan-Jen

2012-01-01

Porous F-WO3/TiO2 (mTiO2) films are prepared on titanium sheet substrates using microarc oxidation (MAO) technique. The X-ray diffraction patterns show that visible-light (Vis) enabling mTiO2 films with a very high content of anatase TiO2 and high loading of WO3 are successfully synthesized at a low applied voltage of 300 V using electrolyte contenting NaF and Na2WO4 without subsequent heat treatment. The cross-sectional transmission electron microscopy micrograph reveals that the mTiO2 films...

Capacitor Property and Leakage Current Mechanism of ZrO2 Thin Dielectric Films Prepared by Anodic Oxidation

Science.gov (United States)

Kamijyo, Masahiro; Onozuka, Tomotake; Shinkai, Satoko; Sasaki, Katsutaka; Yamane, Misao; Abe, Yoshio

2003-07-01

Polycrystalline ZrO2 thin film capacitors were prepared by anodizing sputter-deposited Zr films. Electrical measurements are performed for the parallel-plate anodized capacitors with an Al-ZrO2-Zr (metal-insulator-metal) structure, and a high capacitance density (0.6 μF/cm2) and a low dielectric loss of nearly 1% are obtained for a very thin-oxide capacitor anodized at 10 V. In addition, the leakage current density of this capacitor is about 1.8 × 10-8 A/cm2 at an applied voltage of 5 V. However, the leakage current is somewhat larger than that of a low-loss HfO2 capacitor. The leakage current density (J) of ZrO2 capacitors as a function of applied electric field (E) was investigated for several capacitors with different oxide thicknesses, by plotting \\ln(J) vs E1/2 curves. As a result, it is revealed that the conduction mechanism is due to the Poole-Frenkel effect, irrespective of the oxide thickness.

Preparation of TiO2/boron-doped diamond/Ta multilayer films and use as electrode materials for supercapacitors

Science.gov (United States)

Shi, Chao; Li, Hongji; Li, Cuiping; Li, Mingji; Qu, Changqing; Yang, Baohe

2015-12-01

We report nanostructured TiO2/boron-doped diamond (BDD)/Ta multilayer films and their electrochemical performances as supercapacitor electrodes. The BDD films were grown on Ta substrates using electron-assisted hot filament chemical vapor deposition. Ti metal layers were deposited on the BDD surfaces by radio frequency magnetron sputtering, and nanostructured TiO2/BDD/Ta thin films were prepared by electrochemical etching and thermal annealing. The successful formation of TiO2 and Ta layered nanostructures was demonstrated using scanning electron and transmission electron microscopies. The electrochemical responses of these electrodes were evaluated by examining their use as electrical double-layer capacitors, using cyclic voltammetry, and galvanostatic charge/discharge and impedance measurements. When the TiO2/BDD/Ta film was used as the working electrode with 0.1 M Na2SO4 as the electrolyte, the capacitor had a specific capacitance of 5.23 mF cm-2 at a scan rate of 5 mV s-1 for a B/C ratio of 0.1% w/w. Furthermore, the TiO2/BDD/Ta film had improved electrochemical stability, with a retention of 89.3% after 500 cycles. This electrochemical behavior is attributed to the quality of the BDD, the surface roughness and electrocatalytic activities of the TiO2 layer and Ta nanoporous structures, and the synergies between them. These results show that TiO2/BDD/Ta films are promising as capacitor electrodes for special applications.

Sensitometric characteristics of UF-4, UF-5, and UFSh-O films in the quantum-energy range of 5-30 keV

International Nuclear Information System (INIS)

Datsko, I.M.; Slabkovskaya, M.A.; Sokolov, A.S.; Uvarova, N.V.; Sheromov, M.A.

1987-01-01

The sensitivity, gamma, and transmission of UF-4, UF-5, and UFSh-O for quanta with energies of 5-30 keV extracted from a beam of synchrotron radiation are measured. UFSh-O photographic film is more sensitive by a factor of 1.5-2 than are the UF-4 and UF-5 films. The gamma of all the films is greatly dependent on the quantum energy

Preparation of Porous F-WO3/TiO2 Films with Visible-Light Photocatalytic Activity by Microarc Oxidation

Directory of Open Access Journals (Sweden)

Chung-Wei Yeh

2012-01-01

Full Text Available Porous F-WO3/TiO2 (mTiO2 films are prepared on titanium sheet substrates using microarc oxidation (MAO technique. The X-ray diffraction patterns show that visible-light (Vis enabling mTiO2 films with a very high content of anatase TiO2 and high loading of WO3 are successfully synthesized at a low applied voltage of 300 V using electrolyte contenting NaF and Na2WO4 without subsequent heat treatment. The cross-sectional transmission electron microscopy micrograph reveals that the mTiO2 films feature porous networks connected by many micron pores. The diffused reflection spectrum displays broad absorbance across the UV-Vis regions and a significant red shift in the band gap energy (∼2.23 eV for the mTiO2 film. Owing to the high specific surface area from the porous microstructure, the mTiO2 film shows a 61% and 50% rate increase in the photocatalytic dye degradation, as compared with the N,C-codoped TiO2 films under UV and Vis irradiation, respectively.

Preparation of CuAlO2 Thin Films by Sol-Gel Method Using Nitrate Solution Dip-Coating

Directory of Open Access Journals (Sweden)

Ehara Takashi

2016-01-01

Full Text Available CuAlO2 thin films are prepared by sol-gel dip-coating followed by annealing in nitrogen atmosphere using copper nitrate and aluminum nitrate as metal source materials. X-ray diffraction (XRD patterns show (003, (006 and (009 oriented peaks of CuAlO2 at annealing temperature of 800 – 1000°C. This result indicates that the CuAlO2 films prepared in the present work are c-axis oriented. XRD peak intensity increase with annealing temperature and becomes maximum at 850°C. The CuAlO2 XRD peak decreased at annealing temperature of 900°C with appearance of a peak of CuO, and then increased again with annealing temperature until 1000 °C. The films have bandgap of 3.4 eV at annealing temperature of 850°C in which the transparency becomes the highest. At the annealing temperature of 850°C, scanning electron microscope (SEM observation reveals that the films are consist of amorphous fraction and microcrystalline CuAlO2 fraction.

Spray pyrolysed Ru:TiO2 thin film electrodes prepared for electrochemical supercapacitor

Science.gov (United States)

Fugare, B. Y.; Thakur, A. V.; Kore, R. M.; Lokhande, B. J.

2018-04-01

Ru doped TiO2 thin films are prepared by using 0.06 M aqueous solution of potassium titanium oxalate (pto), and 0.005 M aqueous solution of ruthenium tri chloride (RuCl3) precursors. The deposition was carried on stainless steel (SS) by using well known ultrasonic spray pyrolysis technique (USPT) at 723° K by maintaining the spray rate 12 cc/min and compressed air flow rate 10 Lmin-1. Prepared Ru:TiO2 thin films were characterized by structurally, morphologically and electrochemically. Deposited RuO2 shows amorphous structure and TiO2 shows tetragonal crystal structure with rutile as prominent phase at very low decomposition temperature. SEM micrographs of RuO2 exhibits porous, interconnected, spherical grains type morphology and TiO2 shows porous, nanorods and nanoplates like morphology and also Ru doped TiO2 shows porous, spherical, granular and nanorods type morphology. The electrochemical cyclic voltammetery shows mixed capacitive behavior. The achieved highest value of specific capacitance 2692 F/g was Ru doped TiO2 electrode in 0.5 M H2SO4.

Characteristics of TiO{sub 2}/ZnO bilayer film towards pH sensitivity prepared by different spin coating deposition process

Energy Technology Data Exchange (ETDEWEB)

Rahman, Rohanieza Abdul, E-mail: rohanieza.abdrahman@gmail.com; Zulkefle, Muhammad Al Hadi, E-mail: alhadizulkefle@gmail.com [NANO-Electronic Centre, Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Abdullah, Wan Fazlida Hanim, E-mail: wanfaz@salam.uitm.edu.my [Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM) Shah Alam, 40450 Shah Alam, Selangor (Malaysia); Rusop, M., E-mail: rusop@salam.uitm.com [NANO-Electronic Centre, Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); NANO-Science Technology Centre (NST), Institute of Science (IOS), Faculty of Applied Science, Universiti Teknologi MARA - UiTM, 40450 Shah Alam, Selangor (Malaysia); Herman, Sukreen Hana, E-mail: hana1617@salam.uitm.edu.my [NANO-Electronic Centre, Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); CoRe of Frontier Materials & Industry Applications, Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia)

2016-07-06

In this study, titanium dioxide (TiO{sub 2}) and zinc oxide (ZnO) bilayer film for pH sensing application will be presented. TiO{sub 2}/ZnO bilayer film with different speed of spin-coating process was deposited on Indium Tin Oxide (ITO), prepared by sol-gel method. This fabricated bilayer film was used as sensing membrane for Extended Gate Field-Effect Transistor (EGFET) for pH sensing application. Experimental results indicated that the sensor is able to detect the sensitivity towards pH buffer solution. In order to obtained the result, sensitivity measurement was done by using the EGFET setup equipment with constant-current (100 µA) and constant-voltage (0.3 V) biasing interfacing circuit. TiO{sub 2}/ZnO bilayer film which the working electrode, act as the pH-sensitive membrane was connected to a commercial metal-oxide semiconductor FET (MOSFET). This MOSFET then was connected to the interfacing circuit. The sensitivity of the TiO2 thin film towards pH buffer solution was measured by dipping the sensing membrane in pH4, pH7 and pH10 buffer solution. These thin films were characterized by using Field Emission Scanning Electron Microscope (FESEM) to obtain the surface morphology of the composite bilayer films. In addition, I-V measurement was done in order to determine the electrical properties of the bilayer films. According to the result obtained in this experiment, bilayer film that spin at 4000 rpm, gave highest sensitivity which is 52.1 mV/pH. Relating the I-V characteristic of the thin films and sensitivity, the sensing membrane with higher conductivity gave better sensitivity.

Nanocrystalline-diamond thin films with high pH and penicillin sensitivity prepared on a capacitive Si-SiO2 structure

International Nuclear Information System (INIS)

Poghossian, A.; Abouzar, M.H.; Razavi, A.; Baecker, M.; Bijnens, N.; Williams, O.A.; Haenen, K.; Moritz, W.; Wagner, P.; Schoening, M.J.

2009-01-01

A capacitive field-effect EDIS (electrolyte-diamond-insulator-semiconductor) sensor with improved pH and penicillin sensitivity has been realised using a nanocrystalline-diamond (NCD) film as sensitive gate material. The NCD growth process on SiO 2 as well as an additional surface treatment in oxidising medium have been optimised to provide high pH-sensitive, non-porous O-terminated films without damage of the underlying SiO 2 layer. The surface morphology of O-terminated NCD thin films and the layer structure of EDIS sensors have been studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods. To establish the relative coverage of the surface functional groups generated by the oxidation of NCD surfaces, X-ray photoelectron spectroscopy analysis was carried out. The hydrophilicity of NCD thin films has been studied by water contact-angle measurements. A nearly Nernstian pH sensitivity of 54-57 mV/pH has been observed for O-terminated NCD films treated in an oxidising boiling mixture for 80 min and in oxygen plasma. The high pH-sensitive properties of O-terminated NCD have been used to develop an EDIS-based penicillin biosensor. A freshly prepared penicillin biosensor possesses a high sensitivity of 85 mV/decade in the concentration range of 0.1-2.5 mM penicillin G. The lower detection limit is 5 μM.

YBa2Cu3O7 films prepared by aerosol MOCVD

International Nuclear Information System (INIS)

Weiss, F.; Froehlich, K.; Haase, R.; Labeau, M.; Selbmann, D.; Senateur, J.P.; Thomas, O.

1993-01-01

In the present study we report on properties of YBa 2 Cu 3 O 7 films prepared by aerosol MOCVD. We give a short description of the process and we focus on the superconducting and related properties of the films deposited on SrTiO 3 , LaAlO 3 and NdGaO 3 single crystalline substrates. (orig.)

The Role of Catalyst Properties on Methanol Oxidation over V{sub 2}O{sub 5}-TiO{sub 2} Using Ozone

Energy Technology Data Exchange (ETDEWEB)

Sahle-Demessie, Endalkachew [US EPA, Office of Research and Development, NRML (United States)], E-mail: sahle-demessie.endalkachew@epa.gov; Almquist, Catherine B. [Miami University, Paper Science and Chemical Engineering Department (United States); Sehker, Sridara Chandra [US EPA, Office of Research and Development, NRML (United States)

2008-08-15

Oxidation of methanol over V{sub 2}O{sub 5} catalysts supported on anatase TiO{sub 2} that were prepared using sol-gel formation and impregnation procedures were investigated. The effects of incorporating Mg in sol-gel to influence the properties of the catalyst were also studied. The process provides an alternative low temperature reaction pathway for reducing emissions of hazardous air pollutant (HAPs) such as methanol and total reduced sulfur compounds (TRS) from pulp and paper mills. The bulk and surface composition of the catalysts were determined by XRD and SEM-EDAX, respectively. The X-ray diffraction patterns of the vanadia-titania catalysts showed mainly the anatase phase of TiO{sub 2}. Temperature programmed desorption of methanol from the different catalyst showed that the {alpha} and {beta} peaks differ significantly with V content and addition of Mg. The combination of gas phase and surface reactions on the V/TiO{sub 2} catalysts reduced the amount of ozone required for high degradation of methanol to mainly CO{sub x} with small quantities of methyl formate. In the absence of ozone the catalysts showed very low activity. It is hypothesized that the ozone is directly influencing the V{sup 4+} and V{sup 5+} redox cycle of the catalyst. Oxidation of methanol is influenced by the operation variables and catalyst properties. The results of this study revealed that the V content has significant influence on the catalyst activity, and the optimum vanadia loading of about 6 wt%. Higher turnover frequencies were observed over sol-gel catalysts than with catalysts prepared by the impregnation method.

Facile sonochemical synthesis of Zn2SnO4-V2O5 nanocomposite as an effective photocatalyst for degradation of Eosin Yellow.

Science.gov (United States)

Ramasamy Raja, V; Rosaline, D Rani; Suganthi, A; Rajarajan, M

2018-06-01

This study presents a novel method for the preparation of Zn 2 SnO 4 /V 2 O 5 nanocomposites via a sonochemical aqueous route. This method is mild, convenient, cheap and efficient. The as prepared samples were characterized by XRD, SEM, EDAX, TEM, BET, FT-IR and UV-DRS spectra. DRS spectrum shows the adsorption edge of Zn 2 SnO 4 -V 2 O 5 in visible region of spectrum. The structural and morphological features of the as synthesized Zn 2 SnO 4 -V 2 O 5 nanocomposites have been observed using both scanning and transmission electron microscopy. BET surface area analysis inferred that the prepared hetero-junctions are meso-porous in nature. The photocatalytic activity of Zn 2 SnO 4 -V 2 O 5 nanocomposites for the degradation of Eosin Yellow (EY) dye under visible light was investigated in detail. 3% Zn 2 SnO 4 -V 2 O 5 nanocomposite exhibited the highest photocatalytic performance (92% of EY degradation) when compared with 2% Zn 2 SnO 4 -V 2 O 5 and 5% Zn 2 SnO 4 -V 2 O 5 . The adsorption of Eosin Yellow followed the pseudo-first order kinetic model. Simultaneously, high stability of the sample was also investigated by four successive photodegradation of EY under visible light. The relationship between photocatalytic activity and the structure of 3% Zn 2 SnO 4 -V 2 O 5 nanocomposite is discussed, and possible reaction mechanisms are also proposed. Therefore, the facile sonochemical preparation process provides some insight into the application of Zn 2 SnO 4 -V 2 O 5 nanocomposites in photocatalytic degradation of organic pollutants. Copyright © 2018. Published by Elsevier B.V.

Preparation and structural characterization of SnO2 and GeO2 methanol steam reforming thin film model catalysts by (HR)TEM

International Nuclear Information System (INIS)

Lorenz, Harald; Zhao Qian; Turner, Stuart; Lebedev, Oleg I.; Van Tendeloo, Gustaaf; Kloetzer, Bernhard; Rameshan, Christoph; Penner, Simon

2010-01-01

Structure, morphology and composition of different tin oxide and germanium oxide thin film catalysts for the methanol steam reforming (MSR) reaction have been studied by a combination of (high-resolution) transmission electron microscopy, selected area electron diffraction, dark-field imaging and electron energy-loss spectroscopy. Deposition of the thin films on NaCl(0 0 1) cleavage faces has been carried out by thermal evaporation of the respective SnO 2 and GeO 2 powders in varying oxygen partial pressures and at different substrate temperatures. Preparation of tin oxide films in high oxygen pressures (10 -1 Pa) exclusively resulted in SnO phases, at and above 473 K substrate temperature epitaxial growth of SnO on NaCl(0 0 1) leads to well-ordered films. For lower oxygen partial pressures (10 -3 to 10 -2 Pa), mixtures of SnO and β-Sn are obtained. Well-ordered SnO 2 films, as verified by electron diffraction patterns and energy-loss spectra, are only obtained after post-oxidation of SnO films at temperatures T ≥ 673 K in 10 5 Pa O 2 . Preparation of GeO x films inevitably results in amorphous films with a composition close to GeO 2 , which cannot be crystallized by annealing treatments in oxygen or hydrogen at temperatures comparable to SnO/SnO 2 . Similarities and differences to neighbouring oxides relevant for selective MSR in the third group of the periodic system (In 2 O 3 and Ga 2 O 3 ) are also discussed with the aim of cross-correlation in formation of nanomaterials, and ultimately, also catalytic properties.

Effect of Mn doping on the structural, magnetic, optical and electrical properties of ZrO_2–SnO_2 thin films prepared by sol–gel method

International Nuclear Information System (INIS)

Anitha, V.S.; Sujatha Lekshmy, S.; Joy, K.

2016-01-01

Manganese doped ZrO_2–SnO_2 (ZrO_2–SnO_2: Mn) nanocomposite thin films were prepared using sol – gel dip coating technique. The structural, morphological, magnetic, optical and electrical properties of the films were studied for undoped and different (15 mol %) manganese doping concentrations. X-ray diffraction pattern (XRD) of films showed the formation of tetragonal phase of SnO_2 and orthorhombic ZrSnO_4. Decrease in crystallinity with increase of Mn concentration was observed for the films. Scanning electron microscopy (SEM) showed the formation of grain growth with an increase in Mn concentration. X-ray photo electron spectroscopy (XPS) confirmed the presence of Zr"4"+, Sn"4"+ and Mn"2"+ ion in ZrO_2–SnO_2: Mn films. Vibrating sample magnetometer (VSM) measurements reveal the presence of magnetic properties in Mn doped nanocomposite thin films. Antiferromagnetic interactions were observed for 5 mol % Mn doping. An average transmittance >80% (UV - Vis region) was observed for all the films. Band gap of the films decreased from 4.78 to 4.41 eV with increase in Mn concentration. Photoluminescence (PL) spectra of the films exhibited emission peaks in visible region of the electromagnetic spectra. Conductivity of the film increased up to 3 mol % Mn doping and then decreased. - Highlights: • ZrO_2–SnO_2: Mn films were deposited onto quartz substrates by Sol –Gel dip coating. • Structural, magnetic, optical and electrical properties of the films were analyzed. • Optical band gap decreased with increase in manganese concentration. • Ferromagnetic behavior was observed for Mn doped films. • These ferromagnetic ZrO_2–SnO_2: Mn films find application in spintronic devices.

Electrical and optical transport characterizations of electron beam evaporated V doped In{sub 2}O{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Islam, Md. Ariful, E-mail: arifapee19@gmail.com [Department of Physics, Rajshahi University of Engineering & Technology (RUET), Rajshahi (Bangladesh); Roy, Ratan Chandra; Hossain, Jaker; Julkarnain, Md.; Khan, Khairul Alam [Department of Applied Physics & Electronic Engineering, University of Rajshahi (Bangladesh)

2017-01-15

Vanadium (5 at. %) doped Indium Oxide (V: In{sub 2}O{sub 3}) thin films with different thicknesses (50 nm, 100 nm and 150 nm) were prepared onto glass substrate by electron beam evaporation technique in a vacuum of about 4 x 10{sup -3} Pa. X-ray diffraction (XRD) pattern revealed that the prepared films of thickness 50 nm are amorphous in nature. Temperature dependence of electrical resistivity was studied in the 300 < T < 475 K temperature range. The films exhibit a metallic behavior in the 300 < T < 380 K range with a positive temperature coefficient of the resistivity (TCR), whereas at T > 380 K, the conduction behavior turns into a semiconductor with a negative TCR. Optical studies revealed that the films of thickness 50 nm possess high transmittance of about 86 % in the near-infrared spectral region. The direct optical band gap lies between 3.26 and 3.00 eV depending on the film thickness. (author)

(5/2-→5/2+) 803 keV beta transition in 147Nd

International Nuclear Information System (INIS)

Lakshminarayana, S.; Srinivasa Rao, M.; Seshagiri Rao, V.; Sastry, D.L.

1978-01-01

The existing experimental results on the 5/2 - →5/2 + 803 keV beta transition in 147 Nd are mutually contradictory to classify it under xi-approximation. To resolve this contradiction, the β-γ directional correlations are performed carefully as a function of energy using a conventional fast-slow coincidence scintillation system. The attenuation factor G 2 in this case turns out to be 0.64 +- 0.05. The results on the longitudinal electron polarization and the shape measurements are combined with the present results and an attempt is made to extract the nuclear matrix elements governing this first forbidden non-unique beta transition following Simm's formalism. Results are discussed based on the final sets of matrix elements. (auth.)

PLD prepared nanostructured Pt-CeO{sub 2} thin films containing ionic platinum

Energy Technology Data Exchange (ETDEWEB)

Vorokhta, M., E-mail: vorohtam@gmail.com [Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague 8 (Czech Republic); Khalakhan, I.; Matolínová, I.; Nováková, J.; Haviar, S. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague 8 (Czech Republic); Lančok, J.; Novotný, M. [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague, Czhech Republic (Czech Republic); Yoshikawa, H. [National Institute for Materials Science, Sengen 1-2-1, Tsukuba, Ibaraki 305-0047 (Japan); Matolín, V. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague 8 (Czech Republic)

2017-02-28

Highlights: • Nanostructured Pt-CeO{sub 2} thin catalyst films were grown on plasma etched and non-etched carbon substrates by pulsed laser deposition. • The surface composition of the nanostructured Pt-CeO{sub 2} films was investigated by surface analysis techniques. • The effect of film roughening was separated from the effect of platinum-ceria atomic interactions. - Abstract: The composition of nanostructured Pt-CeO{sub 2} films on graphite substrates prepared by pulsed laser deposition has been investigated by means of hard X-ray photoelectron spectroscopy, scanning electron microscopy, high resolution transmission electron microscopy, and atomic force microscopy. The influence of morphology of the graphite substrates was investigated with respect to the relative concentrations of ionic and metallic Pt species in the films. It was found that the degree of Pt{sup 2+} enrichment is directly related to the surface morphology of graphite substrates. In particular, the deposition of Pt-CeO{sub 2} films on rough graphite substrate etched in oxygen plasma yielded nanostructured Pt-CeO{sub 2} catalyst films with high surface area and high Pt{sup 2+}/Pt{sup 0} ratio. The presented results demonstrate that PLD is a suitable method for the preparation of thin Pt-CeO{sub 2} catalyst films for fuel cell applications.

Vibrational spectroscopy and analytical electron microscopy studies of Fe-V-O and In-V-O thin films

CERN Document Server

Vuk, A S; Drazic, G; Colomban, P

2002-01-01

Orthovanadate (M sup 3 sup + VO sub 4; M= Fe, In) and vanadate (Fe sub 2 V sub 4 O sub 1 sub 3) thin films were prepared using sol-gel synthesis and dip coating deposition. Using analytical electron microscopy (AEM), the chemical composition and the degree of crystallization of the phases present in the thin Fe-V-O films were investigated. TEM samples were prepared in both orientations: parallel (plan view) and perpendicular (cross section) to the substrate. In the first stages of crystallization, when the particle sizes were in the nanometer range, the classical identification of phases using electron diffraction was not possible. Instead of measuring d values, experimentally selected area electron diffraction (SAED) patterns were compared to calculated (simulated) patterns in order to determine the phase composition. The problems of evaluating the ratio of amorphous and crystalline phases in thin films are reported. Results of TEM and XRD as well as IR and Raman spectroscopy showed that the films made at lo...

Nanocrystalline-diamond thin films with high pH and penicillin sensitivity prepared on a capacitive Si-SiO{sub 2} structure

Energy Technology Data Exchange (ETDEWEB)

Poghossian, A. [Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Campus Juelich, Juelich (Germany); Institute of Bio- and Nanosystems (IBN-2), Research Centre Juelich GmbH, Juelich (Germany)], E-mail: a.poghossian@fz-juelich.de; Abouzar, M.H.; Razavi, A.; Baecker, M. [Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Campus Juelich, Juelich (Germany); Institute of Bio- and Nanosystems (IBN-2), Research Centre Juelich GmbH, Juelich (Germany); Bijnens, N. [Institute for Materials Research, Hasselt University, Diepenbeek (Belgium); Williams, O.A.; Haenen, K. [Institute for Materials Research, Hasselt University, Diepenbeek (Belgium); Division IMOMEC, IMEC vzw., Diepenbeek (Belgium); Moritz, W. [Humboldt University Berlin, Berlin (Germany); Wagner, P. [Institute for Materials Research, Hasselt University, Diepenbeek (Belgium); Schoening, M.J. [Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Campus Juelich, Juelich (Germany); Institute of Bio- and Nanosystems (IBN-2), Research Centre Juelich GmbH, Juelich (Germany)

2009-10-30

A capacitive field-effect EDIS (electrolyte-diamond-insulator-semiconductor) sensor with improved pH and penicillin sensitivity has been realised using a nanocrystalline-diamond (NCD) film as sensitive gate material. The NCD growth process on SiO{sub 2} as well as an additional surface treatment in oxidising medium have been optimised to provide high pH-sensitive, non-porous O-terminated films without damage of the underlying SiO{sub 2} layer. The surface morphology of O-terminated NCD thin films and the layer structure of EDIS sensors have been studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods. To establish the relative coverage of the surface functional groups generated by the oxidation of NCD surfaces, X-ray photoelectron spectroscopy analysis was carried out. The hydrophilicity of NCD thin films has been studied by water contact-angle measurements. A nearly Nernstian pH sensitivity of 54-57 mV/pH has been observed for O-terminated NCD films treated in an oxidising boiling mixture for 80 min and in oxygen plasma. The high pH-sensitive properties of O-terminated NCD have been used to develop an EDIS-based penicillin biosensor. A freshly prepared penicillin biosensor possesses a high sensitivity of 85 mV/decade in the concentration range of 0.1-2.5 mM penicillin G. The lower detection limit is 5 {mu}M.

Enhanced Visible Light Photocatalytic Activity of V2O5 Cluster Modified N-Doped TiO2 for Degradation of Toluene in Air

Directory of Open Access Journals (Sweden)

Fan Dong

2012-01-01

Full Text Available V2O5 cluster-modified N-doped TiO2 (N-TiO2/V2O5 nanocomposites photocatalyst was prepared by a facile impregnation-calcination method. The effects of V2O5 cluster loading content on visible light photocatalytic activity of the as-prepared samples were investigated for degradation of toluene in air. The results showed that the visible light activity of N-doped TiO2 was significantly enhanced by loading V2O5 clusters. The optimal V2O5 loading content was found to be 0.5 wt.%, reaching a removal ratio of 52.4% and a rate constant of 0.027 min−1, far exceeding that of unmodified N-doped TiO2. The enhanced activity is due to the deposition of V2O5 clusters on the surface of N-doped TiO2. The conduction band (CB potential of V2O5 (0.48 eV is lower than the CB level of N-doped TiO2 (−0.19 V, which favors the photogenerated electron transfer from CB of N-doped TiO2 to V2O5 clusters. This function of V2O5 clusters helps promote the transfer and separation of photogenerated electrons and holes. The present work not only displays a feasible route for the utilization of low cost V2O5 clusters as a substitute for noble metals in enhancing the photocatalysis but also demonstrates a facile method for preparation of highly active composite photocatalyst for large-scale applications.

Electrical transport properties of MoO3 thin films prepared by laser assisted evaporation

International Nuclear Information System (INIS)

Lopez-Carreno, L.D.; Pardo, A.; Zuluaga, M.; Torres, J.; Alfonso, J.E.; Cortes-Bracho, O.L.

2007-01-01

In the present paper the growth of MoO 3 thin films on common glass substrates are described. The films were prepared by evaporation of a MoO 3 target with a CO 2 laser (10.6 μm), operating in the continuous wave mode. The effect of substrate temperature on the crystallographic structure and electrical properties of MoO 3 thin films was studied. The chemical composition of the different species formed on the films surface was obtained by X-ray photoelectron spectroscopy (XPS) and the crystalline structure was studied with X-ray diffraction (XRD). The electrical conductivity of the films was determined using the standard four-points method. Conductivity of the films varied from de 10 -9 to 10 -5 (Ωcm) -1 in the 300-600 K temperature range. Arrhenius-type plots for the electrical conductivity indicate the presence of at least two different conduction mechanisms. The I-V characteristic curve shows an ohmic behavior only in the 4.5-60 V range. Outside this interval the I-V curve has a behavior described by a power law. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

SnO2 thin-films prepared by a spray-gel pyrolysis: Influence of sol properties on film morphologies

International Nuclear Information System (INIS)

Luyo, Clemente; Fabregas, Ismael; Reyes, L.; Solis, Jose L.; Rodriguez, Juan; Estrada, Walter; Candal, Roberto J.

2007-01-01

Nanostructured tin oxide films were prepared by depositing different sols using the so-called spray-gel pyrolysis process. SnO 2 suspensions (sols) were obtained from tin (IV) tert-amyloxide (Sn(t-OAm) 4 ) or tin (IV) chloride pentahydrate (SnCl 4 .5H 2 O) precursors, and stabilized with ammonia or tetraethylammonium hydroxide (TEA-OH). Xerogels from the different sols were obtained by solvent evaporation under controlled humidity. The Relative Gelling Volumes (RGV) of these sols strongly depended on the type of precursor. Xerogels obtained from inorganic salts gelled faster, while, as determined by thermal gravimetric analysis, occluding a significant amount of volatile compounds. Infrared spectroscopic analysis was performed on raw and annealed xerogels (300, 500 deg. C, 1 h). Annealing removed water and ammonium or alkyl ammonium chloride, increasing the number of Sn-O-Sn bonds. SnO 2 films were prepared by spraying the sols for 60 min onto glass and alumina substrates at 130 deg. C. The films obtained from all the sols were amorphous or displayed a very small grain size, and crystallized after annealing at 400 deg. C or 500 deg. C in air for 2 h. X-ray diffraction analysis showed the presence of the cassiterite structure and line broadening indicated a polycrystalline material with a grain size in the nanometer range. Results obtained from Scanning Electron Microscopy analysis demonstrated a strong dependence of the film morphology on the RGV of the sols. Films obtained from Sn(t-OAm) 4 showed a highly textured morphology based on fiber-shape bridges, whereas the films obtained from SnCl 4 .5H 2 O had a smoother surface formed by 'O-ring' shaped domains. Lastly, the performance of these films as gas sensor devices was tested. The conductance (sensor) response for ethanol as a target analyte was of the same order of magnitude for the three kinds of films. However, the response of the highly textured films was more stable with shorter response times

Simple O2 Plasma-Processed V2O5 as an Anode Buffer Layer for High-Performance Polymer Solar Cells

DEFF Research Database (Denmark)

Bao, Xichang; Zhu, Qianqian; Wang, Ting

2015-01-01

A simple O2 plasma processing method for preparation of a vanadium oxide (V2O5) anode buffer layer on indium tin oxide (ITO)-coated glass for polymer solar cells (PSCs) is reported. The V2O5 layer with high transmittance and good electrical and interfacial properties was prepared by spin coating...... the illumination of AM 1.5G (100 mW/cm2). Compared to that of the control device with PBDTTT-C:PC71BM as the active layer and PEDOT:PSS (PCE of 6.52%) and thermally annealed V2O5 (PCE of 6.27%) as the anode buffer layer, the PCE was improved by 15.6 and 20.2%, respectively, after the introduction of a V2O5 (O2...... plasma) anode buffer layer. The improved PCE is ascribed to the greatly improved fill factor and enhanced short-circuit current density of the devices, which benefited from the change in the work function of V2O5, a surface with many dangling bonds for better interfacial contact, and the excellent charge...

Synthesis and electronic properties of Fe2TiO5 epitaxial thin films

Science.gov (United States)

Osada, Motoki; Nishio, Kazunori; Hwang, Harold Y.; Hikita, Yasuyuki

2018-05-01

We investigate the growth phase diagram of pseudobrookite Fe2TiO5 epitaxial thin films on LaAlO3 (001) substrates using pulsed laser deposition. Control of the oxygen partial pressure and temperature during deposition enabled selective stabilization of (100)- and (230)-oriented films. In this regime, we find an optical gap of 2.1 eV and room temperature resistivity in the range of 20-80 Ω cm, which are significantly lower than α-Fe2O3, making Fe2TiO5 potentially an ideal inexpensive visible-light harvesting semiconductor. These results provide a basis to incorporate Fe2TiO5 in oxide heterostructures for photocatalytic and photoelectrochemical applications.

TiO 2 Thin Films Prepared via Adsorptive Self-Assembly for Self-Cleaning Applications

KAUST Repository

Xi, Baojuan

2012-02-22

Low-cost controllable solution-based processes for preparation of titanium oxide (TiO 2) thin films are highly desirable, because of many important applications of this oxide in catalytic decomposition of volatile organic compounds, advanced oxidation processes for wastewater and bactericidal treatments, self-cleaning window glass for green intelligent buildings, dye-sensitized solar cells, solid-state semiconductor metal-oxide solar cells, self-cleaning glass for photovoltaic devices, and general heterogeneous photocatalysis for fine chemicals etc. In this work, we develop a solution-based adsorptive self-assembly approach to fabricate anatase TiO 2 thin films on different glass substrates such as simple plane glass and patterned glass at variable compositions (normal soda lime glass or solar-grade borofloat glass). By tuning the number of process cycles (i.e., adsorption-then-heating) of TiO 2 colloidal suspension, we could facilely prepare large-area TiO 2 films at a desired thickness and with uniform crystallite morphology. Moreover, our as-prepared nanostructured TiO 2 thin films on glass substrates do not cause deterioration in optical transmission of glass; instead, they improve optical performance of commercial solar cells over a wide range of incident angles of light. Our as-prepared anatase TiO 2 thin films also display superhydrophilicity and excellent photocatalytic activity for self-cleaning application. For example, our investigation of photocatalytic degradation of methyl orange indicates that these thin films are indeed highly effective, in comparison to other commercial TiO 2 thin films under identical testing conditions. © 2012 American Chemical Society.

A comparative study: Effect of plasma on V{sub 2}O{sub 5} nanostructured thin films

Energy Technology Data Exchange (ETDEWEB)

Singh, Megha; Kumar, Prabhat; Sharma, Rabindar K., E-mail: rkrksharma6@gmail.com; Reddy, G. B. [Thin film laboratory, Department of Physics, Indian Institute of Technology Delhi, Delhi (India)

2016-05-06

Vanadium pentoxide nanostructured thin films (NSTs) have been studied to analyze the effect of plasma on nanostructures grown and morphology of films deposited using sublimation process. Nanostructured thin films were deposited on glass substrates, one in presence of oxygen plasma and other in oxygen environment (absence of plasma). Films were characterized using XRD, Raman spectroscopy, SEM and HRTEM. XRD studies revealed α-V{sub 2}O{sub 5} films (orthorhombic phase) with good crystallinity. However, film deposited in presence of plasma have higher peak intensities as compared to those deposited in absence of plasma. Raman studies also support these finding following same trends of considerable increase in intensity in case of film deposited in presence of plasma. SEM micrographs makes the difference more visible, as film deposited in plasma have well defined plate like structures whereas other film have not-clearly-defined petal-like structures. HRTEM results show orthorhombic phase with 0.39 nm interplanar spacing, as reported by XRD. Results are hereby in good agreement with each other.

Crystal Structure And Optical Properties Of TiO2 Thin Films Prepared By Reactive RF Magnetron Sputtering

Directory of Open Access Journals (Sweden)

Goto S.

2015-06-01

Full Text Available In sputtering deposition process of TiO2, metal Ti or sintered TiO2 target is used as deposition source. In this study, we have compared the characteristic of target materials. When TiO2 target was used, stoichiometric TiO2 films was deposited under the Ar atmosphere containing 1.0% of oxygen. The highest sputtering rate under this atmosphere was 3.9nm/min at 3.4W/cm2. But, sintered TiO2 target is fragile and cannot endure higher density of input power than 3.4W/cm2. On the other hand, Ti target needs higher oxygen concentration (8% in sputtering gas atmosphere for obtaining rutile/anatase. Even though Ti target can be input twice power density of 7.9W/cm2, the highest deposition rate for Ti target was 1.4/nm, which was ~35% of the highest rate for TiO2 target. Then we have study out the composite target consisting of Ti plate and TiO2 chips. Using the composite target, stoichiometric TiO2 films were prepared in the rate of 9.6nm/min at 6.8 W/cm2 under the atmosphere of Ar/2.5%O2. Furthermore, we have found that the TiO2 films obtained from the composite target consisted of about 100% anatase, whereas TiO2 films obtained from other target have rutile dominant structure. The optical band gap energy of the film is determined by using the Tauc plot. The calculated band gap energies for the films deposited by Ti target and composite target were 2.95 and 3.24eV, which are equivalent to that of rutile and anatase structure, respectively.

Improved optical response and photocatalysis for N-doped titanium oxide (TiO2) films prepared by oxidation of TiN

International Nuclear Information System (INIS)

Wan, L.; Li, J.F.; Feng, J.Y.; Sun, W.; Mao, Z.Q.

2007-01-01

In order to improve the photocatalytic activity, N-doped titanium oxide (TiO 2 ) films were obtained by thermal oxidation of TiN films, which were prepared on Ti substrates by ion beam assisted deposition (IBAD). The dominating rutile TiO 2 phase was found in films after thermal oxidation. According to the results of X-ray photoelectron spectroscopy (XPS), the residual N atoms occupied O-atom sites in TiO 2 lattice to form Ti-O-N bonds. UV-vis spectra revealed the N-doped TiO 2 film had a red shift of absorption edge. The maximum red shift was assigned to the sample annealed at 750 deg. C, with an onset wavelength at 600 nm. The onset wavelength corresponded to the photon energy of 2.05 eV, which was nearly 1.0 eV below the band gap of pure rutile TiO 2 . The effect of nitrogen was responsible for the enhancement of photoactivity of N-doped TiO 2 films in the range of visible light

Low-temperature preparation of rutile-type TiO2 thin films for optical coatings by aluminum doping

Science.gov (United States)

Ishii, Akihiro; Kobayashi, Kosei; Oikawa, Itaru; Kamegawa, Atsunori; Imura, Masaaki; Kanai, Toshimasa; Takamura, Hitoshi

2017-08-01

A rutile-type TiO2 thin film with a high refractive index (n), a low extinction coefficient (k) and small surface roughness (Ra) is required for use in a variety of optical coatings to improve the controllability of the reflection spectrum. In this study, Al-doped TiO2 thin films were prepared by pulsed laser deposition, and the effects of Al doping on their phases, optical properties, surface roughness and nanoscale microstructure, including Al distribution, were investigated. By doping 5 and 10 mol%Al, rutile-type TiO2 was successfully prepared under a PO2 of 0.5 Pa at 350-600 °C. The nanoscale phase separation in the Al-doped TiO2 thin films plays an important role in the formation of the rutile phase. The 10 mol%Al-doped rutile-type TiO2 thin film deposited at 350 °C showed excellent optical properties of n ≈ 3.05, k ≈ 0.01 (at λ = 400 nm) and negligible surface roughness, at Ra ≈ 0.8 nm. The advantages of the superior optical properties and small surface roughness of the 10 mol%Al-doped TiO2 thin film were confirmed by fabricating a ten-layered dielectric mirror.

Preparation of Pb(Zr0.52Ti0.48)O3 thin films on Pt/RuO2 double electrode by a new sol-gel route

International Nuclear Information System (INIS)

Kim, S.; Choi, Y.; Kim, C.; Oh, Y.

1997-01-01

Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) thin film on Pt/RuO 2 double electrode was successfully prepared by using new alkoxide endash alkanolamine, sol-gel method. It was observed that the use of Pt/RuO 2 double electrode reduced leakage current, resulting in a marked improvement in the leakage characteristics and more reliable capacitors. Typical P-E hysteresis behavior was observed even at low applied voltage of 5 V, manifesting greatly improved remanance and coercivity. Fatigue and breakdown characteristic, measured at 5 V, showed stable behavior and no degradation in polarization was observed up to 10 11 cycles.copyright 1997 Materials Research Society

Synthesis of nanostructured solid-state phases of V{sub 7}O{sub 16} and V{sub 2}O{sub 5} compounds for ppb-level detection of ammonia

Energy Technology Data Exchange (ETDEWEB)

Huotari, J., E-mail: joni.huotari@ee.oulu.fi [Faculty of Information Technology and Electrical Engineering, P.O. Box 4500, FIN-90014, University of Oulu (Finland); Lappalainen, J. [Faculty of Information Technology and Electrical Engineering, P.O. Box 4500, FIN-90014, University of Oulu (Finland); Eriksson, J.; Bjorklund, R. [Department of Physics, Chemistry and Biology, Linköping University, SE-581 83, Linköping (Sweden); Heinonen, E. [Center of Microscopy and Nanotechnology, Erkki Koiso-Kanttilankatu 3, Tietotalo 1, Linnanmaa, FIN-90570, Oulu (Finland); Miinalainen, I. [Biocenter Oulu, P.O. Box 5000, FI-90014, University of Oulu (Finland); Puustinen, J. [Faculty of Information Technology and Electrical Engineering, P.O. Box 4500, FIN-90014, University of Oulu (Finland); Lloyd Spetz, A. [Faculty of Information Technology and Electrical Engineering, P.O. Box 4500, FIN-90014, University of Oulu (Finland); Department of Physics, Chemistry and Biology, Linköping University, SE-581 83, Linköping (Sweden)

2016-08-05

Solid state phase of V{sub 7}O{sub 16} with separate V{sub 2}O{sub 5} phase were fabricated by pulsed laser deposition. The crystal structure and symmetry of the deposited films were studied with X-ray diffraction and Raman spectroscopy, respectively. Rietveld analysis was performed to the X-ray diffraction measurement results. The surface potentials and morphologies of the films were studied with atomic force microscopy, and microstructure of the thin films was analysed by transmission electron microscopy. Raman spectroscopy and Rietveld refinement results confirmed that the thin-film crystal structures varied between orthorombic V{sub 2}O{sub 5} phase and another phase, triclinic V{sub 7}O{sub 16}, previously found only in the walls of vanadium oxide nanotubes (VO{sub x}-NT), bound together with organic amine. We have earlier presented the first results of stable and pure metal-oxide solid-state phase of V{sub 7}O{sub 16} manufactured from ceramic V{sub 2}O{sub 5} target. Here we show more detailed study of these structures. The microstructure studies showed a variation on the porosity of the films according to crystal structures and also some fibre-like nanostructures were found in the films. The surface morphology depended strongly on the crystal structure and the surface potential studies showed ∼50 meV difference in the work function values between the phases. Compounds were found to be extremely sensitive towards ammonia, NH{sub 3}, down to ∼40 ppb concentrations, and have shown to have the stability and selectivity to control the Selective Catalytic Reduction process, where nitrogen oxides are reduced by ammonia in, e.g. diesel exhausts. - Highlights: • The triclinic V{sub 7}O{sub 16} phase is proven to exist in solid state thin-film form. • The existence of V{sub 7}O{sub 16} in thin-film form is proven by several methods. • The structure of mixed V{sub 7}O{sub 16} and V{sub 2}O{sub 5} is proven to be sensitive to NH{sub 3} at ppb-level.

Vanadium oxides (V{sub 2}O{sub 5}) prepared with different methods for application as counter electrodes in dye-sensitized solar cells (DSCs)

Energy Technology Data Exchange (ETDEWEB)

Wu, Kezhong; Sun, Xiaolong; Duan, Chongyuan; Gao, Jing; Wu, Mingxing [Hebei Normal University, College of Chemistry and Material Science, Key Laboratory of Inorganic Nano-materials of Hebei Province, Shijiazhuang City, Hebei Province (China)

2016-09-15

V{sub 2}O{sub 5} was synthesized by four different procedures employing thermal decomposition, sol-gel, and hydrothermal methods which were subsequently introduced into dye-sensitized solar cells (DSCs) as counter electrode (CE) catalysts for the regeneration of traditional iodide/triiodide (I{sup -}/I{sub 3} {sup -}) redox couple. The catalytic activities of as-prepared V{sub 2}O{sub 5} were significantly affected by the synthetic routes as evidenced by cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel polarization curve. Power conversion efficiency (PCE) of the DSCs employing V{sub 2}O{sub 5} CE, fabricated by thermal decomposition method, was observed to be 3.80 % by using citric acid as an additive, while the PCE of the DSCs using V{sub 2}O{sub 5} CE prepared by hydrothermal and thermal decomposition methods without additive, as well as by a sol-gel procedure, was determined to be 2.13, 2.08, and 2.04 %, respectively. (orig.)

Electrical characteristics and preparation of (Ba0.5Sr0.5)TiO3 films by spray pyrolysis and rapid thermal annealing

International Nuclear Information System (INIS)

Koo, Horngshow; Ku, Hongkou; Kawai, Tomoji; Chen Mi

2007-01-01

Functional films of (Ba 0.5 Sr 0.5 )TiO 3 on Pt (1000 A)/Ti (100 A)/SiO 2 (2000 A)/Si substrates are prepared by spray pyrolysis and subsequently rapid thermal annealing. Barium nitrate, strontium nitrate and titanium isopropoxide are used as starting materials with ethylene glycol as solvent. For (Ba 0.5 Sr 0.5 )TiO 3 functional thin film, thermal characteristics of the precursor powder scratched from as-sprayed films show a remarkable peak around 300-400degC and 57.7% weight loss up to 1000degC. The as-sprayed precursor film with coffee-like color and amorphous-like phase is transformed into the resultant film with white, crystalline perovskite phase and characteristic peaks (110) and (100). The resultant films show correspondent increases of dielectric constant, leakage current and dissipation factor with increasing annealing temperatures. The dielectric constant is 264 and tangent loss is 0.21 in the resultant films annealed at 750degC for 5 min while leakage current density is 1.5x10 -6 A/cm 2 in the film annealed at 550degC for 5 min. (author)

Graphene Oxide-TiO2 Nanocomposite Films for Electron Transport Applications

Science.gov (United States)

Saleem, Abida; Ullah, Naveed; Khursheed, Kamran; Iqbal, Tahir; Shah, Saqlain A.; Asjad, Muhammad; Sarwar, Nazim; Saleem, Murtaza; Arshad, Muhammad

2018-03-01

Graphene oxide-titanium dioxide (GO-TiO2) nanocomposite thin films were prepared for application as the window layer of perovskite solar cells. Graphene oxide (GO) was prepared by a modified Hummer's method, and titanium dioxide (TiO2) nanoparticles were synthesized by hydrothermal solution method. Thin films of GO-TiO2 nanocomposite were prepared with different wt.% of GO by spin coating on indium tin oxide (ITO) substrate followed by annealing at 150°C. X-ray diffraction analysis revealed rutile phase of TiO2 nanostructures. The bandgap of the pure TiO2 thin film was found to be 3.5 eV, reducing to 2.9 eV for the GO-TiO2 nanocomposites with a red-shift towards higher wavelength. Furthermore, thermal postannealing at 400°C improved the transparency in the visible region and decreased the sheet resistance. Morphological and elemental analysis was performed by scanning electron microscopy and energy-dispersive x-ray spectroscopy, respectively. The current-voltage characteristic of the GO-TiO2 nanocomposites indicated Ohmic contact with the ITO substrate. The chemical composition of the as-synthesized GO-TiO2 nanocomposites was investigated by x-ray photoelectron spectroscopy (XPS). The results presented herein demonstrate a new, low-temperature solution-processing approach to obtain rGO-TiO2 composite material for use as the electron transport layer of perovskite solar cells.

Atomic layer deposition and properties of mixed Ta2O5 and ZrO2 films

Directory of Open Access Journals (Sweden)

Kaupo Kukli

2017-02-01

Full Text Available Thin solid films consisting of ZrO2 and Ta2O5 were grown by atomic layer deposition at 300 °C. Ta2O5 films doped with ZrO2, TaZr2.75O8 ternary phase, or ZrO2 doped with Ta2O5 were grown to thickness and composition depending on the number and ratio of alternating ZrO2 and Ta2O5 deposition cycles. All the films grown exhibited resistive switching characteristics between TiN and Pt electrodes, expressed by repetitive current-voltage loops. The most reliable windows between high and low resistive states were observed in Ta2O5 films mixed with relatively low amounts of ZrO2, providing Zr to Ta cation ratio of 0.2.

Formation of high-Tc YBa2Cu3O(7-delta) films on Y2BaCuO5 substrate

Science.gov (United States)

Wang, W. N.; Lu, H. B.; Lin, W. J.; Yao, P. C.; Hsu, H. E.

1988-07-01

High-Tc superconducting YBa2Cu3O(7-delta) films have been successfully prepared on green Y2BaCuO5 (2115) ceramic substrate. The films have been formed by RF sputtering and screen printing with post annealing at 925 C. Regarding superconducting features, the sharp resistivity drop with Tc onset around 95 K (midpoint 84 K) and 99 K (midpoint 89 K) has been observed for RF sputtered and printed films respectively. Both films show the excellent adhesion towards the 2115 substrate. Powder X-ray diffraction profiles indicate a majority of 1237 phase with preferred orientation for RF sputtered thin film.

Preparation of Zinc Oxide (ZnO) Thin Film as Transparent Conductive Oxide (TCO) from Zinc Complex Compound on Thin Film Solar Cells: A Study of O2 Effect on Annealing Process

Science.gov (United States)

Muslih, E. Y.; Kim, K. H.

2017-07-01

Zinc oxide (ZnO) thin film as a transparent conductive oxide (TCO) for thin film solar cell application was successfully prepared through two step preparations which consisted of deposition by spin coating at 2000 rpm for 10 second and followed by annealing at 500 °C for 2 hours under O2 and ambient atmosphere. Zinc acetate dehydrate was used as a precursor which dissolved in ethanol and acetone (1:1 mol) mixture in order to make a zinc complex compound. In this work, we reported the O2 effect, reaction mechanism, structure, morphology, optical and electrical properties. ZnO thin film in this work shows a single phase of wurtzite, with n-type semiconductor and has band gap, carrier concentration, mobility, and resistivity as 3.18 eV, 1.21 × 10-19cm3, 11 cm2/Vs, 2.35 × 10-3 Ωcm respectively which is suitable for TCO at thin film solar cell.

Photoluminescence and electrochemical properties of transparent CeO{sub 2}-ZnO nanocomposite thin films prepared by Pechini method

Energy Technology Data Exchange (ETDEWEB)

Sani, Z.K.; Ghodsi, F.E.; Mazloom, J. [University of Guilan, Department of Physics, Faculty of Science, Namjoo Ave, P.O. Box 41335-1914, Rasht (Iran, Islamic Republic of)

2017-02-15

Nanocomposite thin films of CeO{sub 2}-ZnO with different molar ratios of Zn/Ce (=0, 0.25, 0.5, 0.75 and 1) were prepared by the Pechini sol-gel route. Various spectroscopic and electrochemical techniques were applied to investigate the films. XRD patterns of all the samples exhibited the peaks corresponding to cubic fluorite structure of ceria and the (101) and (103) peaks of ZnO with hexagonal structure was just observed in the sample with molar ratio of 1. EDS confirmed the presence of constituent of element in the samples. FESEM images of the films showed a surface composed of nanograins. AFM analysis revealed that root mean square roughness was enhanced as molar ratio of Zn/Ce increased. Moreover, fractal dimension of surfaces were calculated by cube counting approach. Optical measurements indicated that the film with molar ratio of 1 has the highest transmission and lowest reflectivity. The optical band gap values varied between 2.95 and 3.42 eV. The compositional dependence of refractive index and extinction coefficient were reported. The UV and blue emission appeared in PL spectra. The highest photoluminescence emission intensity was observed in the 1:1 molar ratio sample. The cyclic voltammetry measurements indicated the highest charge density (9.75 mC cm{sup -2}) and diffusion coefficient (3.507 x 10{sup -17} cm{sup 2} s{sup -1}) belonged to the Ce/Zn (1:1) thin film. (orig.)

Polycrystalline V2O5/Na0.33V2O5 electrode material for Li+ ion redox supercapacitor

International Nuclear Information System (INIS)

Manikandan, Ramu; Justin Raj, C.; Rajesh, Murugesan; Kim, Byung Chul; Park, Sang Yeup; Cho, Bo-Bae; Yu, Kook Hyun

2017-01-01

Highlights: • Different polycrystalline V 2 O 5 /Na 0.33 V 2 O 5 nanostructures were synthesized via simple co-precipitation technique. • The various molar ratios of NaOH precipitator determine the morphology, structural and electrochemical properties of V/Na. • The equimolar ratio of reactant and precipitator shows the formation of ∼96% of pure crystalline phase of V 2 O 5 . • Li + ions intercalation and deintercalation process enhanced the specific capacitance. - Abstract: This work essentially offers a new kind of V 2 O 5 /Na 0.33 V 2 O 5 as electrochemical active material for the development of Li + ion redox supercapacitors. Here, polycrystalline mixed phase of V 2 O 5 /Na 0.33 V 2 O 5 (V/Na) nanostructures are synthesized via simple co-precipitation technique. The various molar ratio of precipitator (NaOH) in the synthesis process displays different nanostructures of V/Na. The structural and morphological properties of V/Na samples are studied using physico-chemical analysis methods. The electrochemical properties of V/Na nanostructured samples are performed using cyclic voltammetry, galvanostatic charge/discharge test and electrochemical impedance spectroscopy techniques in 1 M LiClO 4 aqueous electrolyte. The sample V/Na synthesized using equimolar ratio of vanadium salt and precipitator displayed nanopellet morphology, which exhibited the highest capacitance value of 334 Fg −1 at 1 Ag −1 discharge current density. Moreover, these polycrystalline V/Na nanostructured electrodes show excellent electrochemical properties with comparable stability after 1000 charge/discharge cycles.

Preparation and characterization of vanadium oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Monfort, O.; Plesch, G. [Comenius University of Bratislava, Faculty of Natural Sciences, Department of Inorganic Chemistry, 84215 Bratislava (Slovakia); Roch, T. [Comenius University of Bratislava, Faculty of Mathematics Physics and Informatics, Department of Experimental Physics, 84248 Bratislava (Slovakia)

2013-04-16

The thermotropic VO{sub 2} films have many applications, since they exhibit semiconductor-conductor switching properties at temperature around 70 grad C. Vanadium oxide thin films were prepared via sol-gel method. Spin coater was used to depose these films on Si/SiO{sub 2} and lime glass substrates. Thin films of V{sub 2}O{sub 5} can be reduced to metastable VO{sub 2} thin films at the temperature of 450 grad C under the pressure of 10{sup -2} Pa. These films are then converted to thermotropic VO{sub 2} at 700 grad C in argon under normal pressure. (authors)

Fabrication of self-assembled ultrathin photochromic films containing mixed-addenda polyoxometalates H5[PMo10V2O40] and 1,10-decanediamine

International Nuclear Information System (INIS)

Wang Zhongliang; Ma Ying; Zhang Ruili; Xu Da; Fu Hongbing; Yao Jiannian

2009-01-01

A layered phosphovanadomolybdate/1,10-decanediamine (1,10-DAD) self-assembled ultrathin film was fabricated by means of alternating adsorption of mixed-addenda polyoxometalates (POMs) (phosphovanadomolybdate, H 5 [PMo 10 V 2 O 40 ]) and 1,10-DAD, and its photochromic properties were investigated. It is found that the self-assembled multilayer (SAM) film shows high-photochromic response, excellent photochromic stability and reversibility. The photochromic behavior of the SAM is closely related to the reduction potentials of addenda atoms in mixed-addenda POMs. In the case of photo-reduced mixed-addenda POMs, the electron is localized on the more reducible atom, and the addenda atoms with higher reduction potentials show prior photochromism compared with those with lower reduction potentials. The coloration speed is improved after introduction of V into molybdenum POM. The well-ordered lamellar structure of the film was well maintained during the coloration. - Graphical abstract: An ordered H 5 [PMo 10 V 2 O 40 ]/1,10-decanediamine ultrathin film was fabricated by a self-assembled technique. The hybrid film displays good photochromism closely related to the reduction potentials of addenda atoms.

Swift heavy ion irradiated SnO_2 thin film sensor for efficient detection of SO_2 gas

International Nuclear Information System (INIS)

Tyagi, Punit; Sharma, Savita; Tomar, Monika; Singh, Fouran; Gupta, Vinay

2016-01-01

Highlights: • Response of Ni"7"+ ion irradiated (100 MeV) SnO_2 film have been performed. • Effect of irradiation on the structural and optical properties of SnO_2 film is studied. • A decrease in operating temperature and increased response is seen after irradiation. - Abstract: Gas sensing response studies of the Ni"7"+ ion irradiated (100 MeV) and non-irradiated SnO_2 thin film sensor prepared under same conditions have been performed towards SO_2 gas (500 ppm). The effect of irradiation on the structural, surface morphological, optical and gas sensing properties of SnO_2 thin film based sensor have been studied. A significant decrease in operating temperature (from 220 °C to 60 °C) and increased sensing response (from 1.3 to 5.0) is observed for the sample after irradiation. The enhanced sensing response obtained for the irradiated SnO_2 thin film based sensor is attributed to the desired modification in the surface morphology and material properties of SnO_2 thin film by Ni"7"+ ions.

Soft chemistry routes to transparent metal oxide thin films. The case of sol–gel synthesis and structural characterization of Ta2O5 thin films from tantalum chloromethoxide

International Nuclear Information System (INIS)

Epifani, Mauro; Zamani, Reza; Arbiol, Jordi; Fabrega, Cristian; Andreu, Teresa; Pace, Giovanni Battista; Siciliano, Pietro; Morante, Joan R.

2014-01-01

Ta 2 O 5 thin films were prepared by spin-coating methanol solutions of Ta chloromethoxide. It was prepared by reacting TaCl 5 with methanol, followed by water addition (H 2 O: Ta molar ratio was 16). Thin films were deposited by spin-coating onto SiO 2 /Si substrates, followed by drying at 90 °C and heat-treatment up to 700 °C. The films were characterized by X-ray diffraction, transmission electron microscopy and field emission scanning electron microscopy. Crystallization was obtained only after heating at 700 °C, in the Ta 2 O 5 orthorhombic phase. The resulting films had a thickness of 100 nm. Their structure was constituted by porous crystals with size up to 50 nm, while the pores had a size of about 10 nm. The results demonstrated that TaCl 5 is very convenient precursor for the wet chemical synthesis of Ta 2 O 5 thin films. - Highlights: • Development of convenient solution synthesis of Ta 2 O 5 thin films; • The precursor chemistry was established and related to the synthesis process; • Uniform films crystallized in the most stable orthorombic Ta 2 O 5 phase;

Influence of Different Substrates on Laser Induced Damage Thresholds at 1064 nm of Ta2O5 Films

International Nuclear Information System (INIS)

Cheng, Xu; Jian-Yong, Ma; Yun-Xia, Jin; Hong-Bo, He; Jian-Da, Shao; Zheng-Xiu, Fan

2008-01-01

Ta 2 O 5 films are prepared on Si, BK7, fused silica, antireflection (AR) and high reflector (HR) substrates by electron beam evaporation method, respectively. Both the optical property and laser induced damage thresholds (LIDTs) at 1064 nm of Ta 2 O 5 films on different substrates are investigated before and after annealing at 673K for 12 h. It is shown that annealing increases the refractive index and decreases the extinction index, and improves the O/Ta ratio of the Ta 2 O 5 films from 2.42 to 2.50. Moreover, the results show that the LIDTs of the Ta 2 O 5 films are mainly correlated with three parameters: substrate property, substoichiometry defect in the films and impurity defect at the interface between the substrate and the films. Details of the laser induced damage models in different cases are discussed

Carbonate hydrates of the heavy alkali metals: preparation and structure of Rb{sub 2}CO{sub 3} . 1.5 H{sub 2}O und Cs{sub 2}CO{sub 3} . 3 H{sub 2}O; Carbonat-Hydrate der schweren Alkalimetalle: Darstellung und Struktur von Rb{sub 2}CO{sub 3} . 1,5 H{sub 2}O und Cs{sub 2}CO{sub 3} . 3 H{sub 2}O

Energy Technology Data Exchange (ETDEWEB)

Cirpus, V.; Wittrock, J.; Adam, A. [Koeln Univ. (Germany). Inst. fuer Anorganische Chemie

2001-03-01

Rb{sub 2}CO{sub 3} . 1.5 H{sub 2}O and Cs{sub 2}CO{sub 3} . 3 H{sub 2}O were prepared from aqueous solution and by means of the reaction of dialkylcarbonates with RbOH and CsOH resp. in hydrous alcoholes. Based on four-circle diffractometer data, the crystal structures were determined (Rb{sub 2}CO{sub 3} . 1.5 H{sub 2}O: C2/c (no. 15), Z = 8, a = 1237.7(2) pm, b = 1385.94(7) pm, c = 747.7(4) pm, {beta} = 120.133(8) , V{sub EZ} = 1109.3(6) . 10{sup 6} pm{sup 3}; Cs{sub 2}CO{sub 3} . 3 H{sub 2}O: P2/c (no. 13), Z = 2, a = 654.5(2) pm, b = 679.06(6) pm, c = 886.4(2) pm, {beta} = 90.708(14) , V{sub EZ} = 393.9(2) . 10{sup 6} pm{sup 3}). Rb{sub 2}CO{sub 3} . 1.5 H{sub 2}O is isostructural with K{sub 2}CO{sub 3} . 1.5 H{sub 2}O. In case of Cs{sub 2}CO{sub 3} . 3 H{sub 2}O no comparable structure is known. Both structures show {sub {infinity}}{sup 1}[(CO{sub 3}{sup 2-})(H{sub 2}O)]-chains, being connected via additional H{sub 2}O forming columns (Rb{sub 2}CO{sub 3} . 1.5 H{sub 2}O) and layers (Cs{sub 2}CO{sub 3} . 3 H{sub 2}O), respectively. (orig.)

Preparation and characterization of Nb{sub 2}O{sub 5}-Al{sub 2}O{sub 3} composite oxide formed by cathodic electroplating and anodizing

Energy Technology Data Exchange (ETDEWEB)

Jang, Joo-Hee; Kim, Tae-Yoo; Kim, Nam-Jeong; Lee, Chang-Hyoung; Park, Eun-Mi [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Park, Chan [Division of Materials Science and Engineering, Pukyong National University, Busan 608-739 (Korea, Republic of); Suh, Su-Jeong, E-mail: suhsj@skku.ac.kr [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Advanced Materials and Process Research Center for IT, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

2011-11-15

Highlights: > We fabricate Nb{sub 2}O{sub 5}-Al{sub 2}O{sub 3}/Al film for high performance thin film capacitor. > The optimum condition of electrolyte composition will coat NbO{sub x} on Al without corrosion of Al during the cathodic electroplating. > Increasing annealing temperature will form Nb{sub 2}O{sub 5} crystalline. > The Al{sub 2}O{sub 3} layer will form between Nb{sub 2}O{sub 5} layer and metal Al after anodizing and the thin film capacitor with Nb{sub 2}O{sub 5}-Al{sub 2}O{sub 3}/Al improve dielectric properties. - Abstract: Al foil was coated with niobium oxide by cathodic electroplating and anodized in a neutral boric acid solution to achieve high capacitance in a thin film capacitor. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) revealed the niobium oxide layer on Al to be a hydroxide-rich amorphous phase. The film was crystalline and had stoichiometric stability after annealing at temperatures up to 600 deg. C followed by anodizing at 500 V, and the specific capacitance of the Nb{sub 2}O{sub 5}-Al{sub 2}O{sub 3} composite oxide was approximately 27% higher than that of Al{sub 2}O{sub 3} without a Nb{sub 2}O{sub 5} layer. The capacitance was quite stable to the resonance frequency. Overall, the Nb{sub 2}O{sub 5}-Al{sub 2}O{sub 3} composite oxide film is a suitable material for thin film capacitors.

Structural and electrical properties of Ta2O5 thin films prepared by ...

Indian Academy of Sciences (India)

The dielectric constant and leakage current density of the Ta2O5 thin films increase with increasing powers of the UV- lamps. Effects of UV- lamp powers on the structural and electrical properties were discussed. Keywords. Chemical vapour deposition processes; oxides; dielectric material; MOS capacitor. 1. Introduction.

Interconnected V2O5 nanoporous network for high-performance supercapacitors.

Science.gov (United States)

Saravanakumar, B; Purushothaman, Kamatchi K; Muralidharan, G

2012-09-26

Vanadium pentoxide (V(2)O(5)) has attracted attention for supercapcitor applications because of its extensive multifunctional properties. In the present study, V(2)O(5) nanoporous network was synthesized via simple capping-agent-assisted precipitation technique and it is further annealed at different temperatures. The effect of annealing temperature on the morphology, electrochemical and structural properties, and stability upon oxidation-reduction cycling has been analyzed for supercapacitor application. We achieved highest specific capacitance of 316 F g(-1) for interconnected V(2)O(5) nanoporous network. This interconnected nanoporous network creates facile nanochannels for ion diffusion and facilitates the easy accessibility of ions. Moreover, after six hundred consecutive cycling processes the specific capacitance has changed only by 24%. A simple cost-effective preparation technique of V(2)O(5) nanoporous network with excellent capacitive behavior, energy density, and stability encourages its possible commercial exploitation for the development of high-performance supercapacitors.

Preparation of ZnO film on p-Si and I-V characteristics of p-Si/n-ZnO

OpenAIRE

Mondal, Shampa; Kanta, Kalyani Prasad; Mitra, Partha

2012-01-01

Zinc oxide (ZnO) thin films were deposited on p-silicon (Si) substrate from ammonium zincate bath following a chemical dipping technique called SILAR. Films in the thickness range 0.5-4.5 µm could be prepared by varying the number of dipping for a fixed concentration (0.125 M) of zincate bath and fixed pH (11.00-11.10). Higher values of dipping produced nonadherent and poor quality films. Structural characterization by X-ray diffraction (XRD) indicates the formation of polycrystalline single ...

Electrical transport properties of MoO{sub 3} thin films prepared by laser assisted evaporation

Energy Technology Data Exchange (ETDEWEB)

Lopez-Carreno, L.D.; Pardo, A.; Zuluaga, M.; Torres, J.; Alfonso, J.E. [Group of Materials with Technological Applications, GMAT, Physics Department, Universidad Nacional de Colombia, Bogota (Colombia); Cortes-Bracho, O.L. [Group of Materials with Technological Applications, GMAT, Physics Department, Universidad Nacional de Colombia, Bogota (Colombia); Electronic Engineering Department, Universidad Nacional de Colombia, Bogota (Colombia)

2007-07-01

In the present paper the growth of MoO{sub 3} thin films on common glass substrates are described. The films were prepared by evaporation of a MoO{sub 3} target with a CO{sub 2} laser (10.6 {mu}m), operating in the continuous wave mode. The effect of substrate temperature on the crystallographic structure and electrical properties of MoO{sub 3} thin films was studied. The chemical composition of the different species formed on the films surface was obtained by X-ray photoelectron spectroscopy (XPS) and the crystalline structure was studied with X-ray diffraction (XRD). The electrical conductivity of the films was determined using the standard four-points method. Conductivity of the films varied from de 10{sup -9} to 10{sup -5} ({omega}cm){sup -1} in the 300-600 K temperature range. Arrhenius-type plots for the electrical conductivity indicate the presence of at least two different conduction mechanisms. The I-V characteristic curve shows an ohmic behavior only in the 4.5-60 V range. Outside this interval the I-V curve has a behavior described by a power law. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Preparation of TiO2 thin films from autoclaved sol containing needle-like anatase crystals

International Nuclear Information System (INIS)

Ge Lei; Xu Mingxia; Fang Haibo; Sun Ming

2006-01-01

A new inorganic sol-gel method was introduced in this paper to prepare TiO 2 thin films. The autoclaved sol with needle-like anatase crystals was synthesized using titanyl sulfate (TiOSO 4 ) and peroxide (H 2 O 2 ) as starting materials. The transparent anatase TiO 2 thin films were prepared on glass slides from the autoclaved sol by sol-gel dip-coating method. A wide range of techniques such as Fourier transform infrared transmission spectra (FT-IR), X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA), scanning electron microscopes, X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible spectrum were applied to characterize the autoclaved sol and TiO 2 thin films. The results indicate that the autoclaved sol is flavescent, semitransparent and stable at room temperature. The anatase crystals of TiO 2 films connect together to form net-like structure after calcined and the films become uniform with increasing heating temperature. The surface of the TiO 2 films contain not only Ti and O elements, but also a small amount of N and Na elements diffused from substrates during heat treatment. The TiO 2 films are transparent and their maximal light transmittances exceed 80% under visible light region

Structure and Properties of La2O3-TiO2 Nanocomposite Films for Biomedical Applications

Science.gov (United States)

Zhang, Lin; Sun, Zhi-Hua; Yu, Feng-Mei; Chen, Hong-Bin

2011-01-01

The hemocompatibility of La2O3-doped TiO2 films with different concentration prepared by radio frequency (RF) sputtering was studied. The microstructures and blood compatibility of TiO2 films were investigated by scan electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-visible optical absorption spectroscopy, respectively. With the increasing of the La2O3 concentrations, the TiO2 films become smooth, and the grain size becomes smaller. Meanwhile, the band gap of the samples increases from 2.85 to 3.3 eV with increasing of the La2O3 content in TiO2 films from 0 to 3.64%. La2O3-doped TiO2 films exhibit n-type semiconductor properties due to the existence of Ti2+ and Ti3+. The mechanism of hemocompatibility of TiO2 film doped with La2O3 was analyzed and discussed. PMID:22162671

Enhanced electrochromic properties of TiO2 nanoporous film prepared based on an assistance of polyethylene glycol

Science.gov (United States)

Xu, Shunjian; Luo, Xiaorui; Xiao, Zonghu; Luo, Yongping; Zhong, Wei; Ou, Hui; Li, Yinshuai

2017-01-01

Polyethylene glycol (PEG) was employed as pore-forming agent to prepare TiO2 nanoporous film based on spin-coating a TiO2 nanoparticle mixed paste on fluorine doped tin oxide (FTO) glass. The electrochromic and optical properties of the obtained TiO2 film were investigated by cyclic voltammetry (CV), chronoamperometry (CA) and UV-Vis spectrophotometer. The results show that the PEG in the mixed paste endows the TiO2 film with well-developed porous structure and improves the uniformity of the TiO2 film, which are helpful for the rapid intercalation and extraction of lithium ions within the TiO2 film and the strengthening of the diffuse reflection of visible light in the TiO2 film. As a result, the TiO2 film derived from the mixed paste with PEG displays higher electrochemical activity and more excellent electrochromic performances compared with the TiO2 film derived from the mixed paste without PEG. The switching times of coloration/bleaching are respectively 10.16/5.65 and 12.77/6.13 s for the TiO2 films with PEG and without PEG. The maximum value of the optical contrast of the TiO2 film with PEG is 21.2% while that of the optical contrast of the TiO2 film without PEG is 14.9%. Furthermore, the TiO2 film with PEG has better stability of the colored state than the TiO2 film without PEG.

Preparation of acid salt M(HPO4)2.nH2 O thin films

International Nuclear Information System (INIS)

Kassem, M.

1998-01-01

The layered crystalline powders of Titanium Phosphate with the formula Ti(HPO 4 ) 2 .nH 2 O (phase α when n=2, phase γ when n=1) were prepared by reaction of titanium three chloride with phosphoric acid under specific thermal conditions. Starting from these powders thin films have been prepared using some methods such as: Thermal evaporation, sol-gel and vapor phase transport. The results of X-ray diffraction and differential thermal deferential analysis show that the temperature plays an important role in the determination of the crystalline phases and the phase transition of the prepared films. (author). 7 refs

(0 0 2-oriented growth and morphologies of ZnO thin films prepared by sol-gel method

Directory of Open Access Journals (Sweden)

Guo Dongyun

2016-09-01

Full Text Available Zinc acetate was used as a starting material to prepare Zn-solutions from solvents and ligands with different boiling temperature. The ZnO thin films were prepared on Si(1 0 0 substrates by spin-coating method. The effect of baking temperature and boiling temperature of the solvents and ligands on their morphologies and orientation was investigated. The solvents and ligands with high boiling temperature were favorable for relaxation of mechanical stress to form the smooth ZnO thin films. As the solvents and ligands with low boiling temperature were used to prepare Zn-solutions, the prepared ZnO thin films showed (0 0 2 preferred orientation. As n-propanol, 2-methoxyethanol, 2-(methylaminoethanol and monoethanolamine were used to prepare Zn-solutions, highly (0 0 2-oriented ZnO thin films were formed by adjusting the baking temperature.

Caracterização de filmes finos de Nb2O5 com propriedades eletrocrômicas Caracterization of OF Nb2O5 thin films with electrochromic properties

Directory of Open Access Journals (Sweden)

C. O. Avellaneda

1998-06-01

Full Text Available The sols for thin electrochromic coatings of Nb2O5 were obtained by synthesis of the niobium butoxide from BuONa and NbCl5. The ~300nm thick films were deposited by dip-coating technique from the alkoxide solution and calcined at 560ºC in O2 atmosphere during 3 hours. The particles size of niobium oxide (V powder (~20mm was obtained from x-ray diffraction using the Scherrer equation. The coatings were characterized by cyclic voltammetry and cronoamperommetry techniques. The spectral variation of the optical transmittance were determined in situ as a function of the cyclical potencial and memory effect. The insertion process of lithium is reversible and change the film color from transparent (T=80% to dark blue (T=20%.

Study on fabrication of TiO{sub 2} thin films by spin – coating and their optical properties

Energy Technology Data Exchange (ETDEWEB)

Zharvan, Vicran, E-mail: vicran.zharvan@gmail.com; Daniyati, Risqa; Nur Ichzan, A.S.; Yudoyono, Gatut; Darminto, E-mail: darminto@physics.its.ac.id [Department of Physics, Institut Teknologi Sepuluh Nopember (ITS), Kampus ITS Sukolilo, Surabaya 60111 (Indonesia)

2016-03-11

Study on fabrication of TiO{sub 2} thin films and their optical properties in UV-VIS spectrum has been conducted. TiO{sub 2} nanopowders were prepared by co-precipitation method with varying mixing duration for 5, 10 and 25 hours using TiCl{sub 3} as precursor. The as-synthesized TiO{sub 2} phase is anatase having crystalline size of 14.25 nm, 13.75 nm and 12.62, respectively for the corresponding mixing duration. Thin films of TiO{sub 2} were fabricated by spin coating method and then checked by XRD diffractometer and UV-Vis Spectrophotometer to examine their structure and band gap energy. The prepared films also contain anatase phase of TiO{sub 2} with respective band gap of 3.70 eV, 3.74 eV and 3.76 eV, depending on the powders and their treatment.

Synthesis of 4-O-glycosylated 1,5-anhydro-D-fructose and of 1,5-anhydro-D-tagatose from a common intermediate 2,3-O-isopropylidene-D-fructose.

Science.gov (United States)

Agoston, Károly; Dékány, Gyula; Lundt, Inge

2009-05-26

Four novel disaccharides of glycosylated 1,5-anhydro-D-ketoses have been prepared: 1,5-anhydro-4-O-beta-D-glucopyranosyl-D-fructose, 1,5-anhydro-4-O-beta-D-galactopyranosyl-D-fructose, 1,5-anhydro-4-O-beta-D-glucopyranosyl-D-tagatose, and 1,5-anhydro-4-O-beta-D-galactopyranosyl-D-tagatose. The common intermediate, 1,5-anhydro-2,3-O-isopropylidene-beta-D-fructopyranose, was prepared from D-fructose and was converted into the D-tagatose derivative by oxidation followed by stereoselective reduction to the 4-epimer. The anhydroketoses thus prepared were glycosylated and deprotected to give the disaccharides.

Chemical synthesis of Fe{sub 2}O{sub 3} thin films for supercapacitor application

Energy Technology Data Exchange (ETDEWEB)

Kulal, P.M.; Dubal, D.P.; Lokhande, C.D. [Holography and Material Research Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, M.S. (India); Fulari, V.J., E-mail: vijayfulari@gmail.com [Holography and Material Research Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, M.S. (India)

2011-02-03

Research highlights: > Simple chemical synthesis of Fe{sub 2}O{sub 3}. > Formation of amorphous and hydrous Fe{sub 2}O{sub 3}. > Potential candidate for supercapacitors. - Abstract: Fe{sub 2}O{sub 3} thin films have been prepared by novel chemical successive ionic layer adsorption and reaction (SILAR) method. Further these films were characterized for their structural, morphological and optical properties by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrum, scanning electron microscopy (SEM), wettability test and optical absorption studies. The XRD pattern showed that the Fe{sub 2}O{sub 3} films exhibit amorphous in nature. Formation of iron oxide compound was confirmed from FTIR studies. The optical absorption showed existence of direct optical band gap of energy 2.2 eV. Fe{sub 2}O{sub 3} film surface showed superhydrophilic nature with water contact angle less than 10{sup o}. The supercapacitive properties of Fe{sub 2}O{sub 3} thin film investigated in 1 M NaOH electrolyte showed supercapacitance of 178 F g{sup -1} at scan rate 5 mV/s.

Bulk to nanostructured vanadium pentaoxide-nanowires (V2O5-NWs) for high energy density supercapacitors

Science.gov (United States)

Ahirrao, Dinesh J.; Mohanapriya., K.; Jha, Neetu

2018-04-01

Vanadium pentoxide (V2O5) has attracted huge attention in field of energy storage including supercapacitor electrodes due to its low cost and layered structure. In this present study, Bulk V2O5 has been prepared by the calcination of ammonium metavanadate followed by the synthesis of V2O5-nanowires (V2O5-NWs) by hydrothermal treatment of bulk V2O5. Obtained V2O5-NWs was further used to fabricate the supercapacitor electrodes. Structure and morphology analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Energy storage capability of as prepared nanowires was investigated by Galvanostatic charge-discharge (GCD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in aqueous electrolyte (1M H2SO4). High specific capacitantance of about 622 F/g was achieved at 1 A/g. Along with high storage by faradic charge storage mechanism; V2O5-NWs electrodes also possess high stability. It could retain 63% of its initial capacitance even after 1000 GCD cycles. Excellent performance of V2O5-NWs promotes its commercial utilization for the development of high performance supercapacitors.

Effect of V2O5 on SrO-ZnO-B2O3-SiO2 glass-ceramics for high temperature sealant application

Science.gov (United States)

Tiwari, Babita; Bhatacharya, S.; Dixit, A.; Gadkari, S. C.; Kothiyal, G. P.

2012-06-01

Glasses in the SrO-ZnO-B2O3-SiO2 (SZBS) system with and without V2O5 were prepared by melt-quench method and transformed into glass-ceramics by controlled crystallization. Investigated glasses and glass-ceramics have thermal expansion coefficients (TEC) in the range of 95-120 × 10-7/°C (30-600 °C), which match closely with TEC of other components of solid oxide fuel cell (SOFC). Study of thermo-physical properties of SZBS glasses revealed the network modifying effect of V2O5. Addition of V2O5 increases the TEC and decreases the viscosity of the glass which is beneficial for making seal with Crofer-22-APU. Microstructural investigations have shown good bonding of SZBS glasses with Crofer-22-APU. Elemental line scans indicate that inter-diffusion of Fe, Cr and Si across interface, which is thought to be responsible for good bonding with Crofer-22-APU.

SO2 and NO removal from flue gas over V2O5/AC at lower temperatures - role of V2O5 on SO2 removal

International Nuclear Information System (INIS)

Ma, Jianrong; Liu, Zhenyu; Liu, Qingya; Guo, Shijie; Huang, Zhanggen; Xiao, Yong

2008-01-01

Supporting V 2 O 5 onto an activated coke (AC) has been reported to significantly increase the AC's activity in simultaneous SO 2 and NO removal from flue gas. To understand the role of V 2 O 5 on SO 2 removal, V 2 O 5 /AC is studied through SO 2 removal reaction, surface analysis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) techniques. It is found that the main role of V 2 O 5 in SO 2 removal over V 2 O 5 /AC is to catalyze SO 2 oxidation through a VOSO 4 -like intermediate species, which reacts with O 2 to form SO 3 and V 2 O 5 . The SO 3 formed transfers from the V sites to AC sites and then reacts with H 2 O to form H 2 SO 4 . At low V 2 O 5 loadings, a V atom is able to catalyze as many as 8 SO 2 molecules to SO 3 . At high V 2 O 5 loadings, however, the number of SO 2 molecules catalyzed by a V atom is much less, due possibly to excessive amounts of V 2 O 5 sites in comparison to the pores available for SO 3 and H 2 SO 4 storage. (author)

Preparation and studies of Eu3+ and Tb3+ co-doped Gd2O3 and Y2O3 sol-gel scintillating films

International Nuclear Information System (INIS)

Morales Ramirez, A. de J; Garcia Murillo, A.; Carrillo Romo, F. de J; Ramirez Salgado, J.; Le Luyer, C.; Chadeyron, G.; Boyer, D.; Moreno Palmerin, J.

2009-01-01

Eu 3+ (2.5 at.%) and Tb 3+ (0.005-0.01 at.%) co-doped gadolinium and yttrium oxide (Gd 2 O 3 and Y 2 O 3 ) powders and films have been prepared using the sol-gel process. High density and optical quality thin films were prepared with the dip-coating technique. Gadolinium (III) 2,4-pentadionate and yttrium (III) 2,4-pentadionate were used as precursors, and europium and terbium in their nitrate forms were used as doping agents. Chemical and structural analyses (infrared spectroscopy, X-ray diffraction and high-resolution transmission electron microscopy) were conducted on both sol-gel precursor powders and dip-coated films. The morphology of thin films heat-treated at 700 o C was studied by means of atomic force microscopy. It was shown that the highly dense and very smooth films had a root mean roughness (RMS) of 2 nm ± 0.2 (A = 0.0075 Tb 3+ ) and 24 nm ± 3.0 (B = 0.01 Tb 3+ ). After treatment at 700 o C, the crystallized films were in the cubic phase and presented a polycrystalline structure made up of randomly oriented crystallites with grain sizes varying from 20 to 60 nm. The X-ray induced emission spectra of Eu 3+ - and Tb 3+ -doped Gd 2 O 3 and Y 2 O 3 powders showed that Tb 3+ contents of 0.005, 0.0075 and 0.01 at.% affected their optical properties. Lower Tb 3+ concentrations (down to 0.005 at.%) in both systems enhanced the light yield.

Fabrication of p-type conductivity in SnO{sub 2} thin films through Ga doping

Energy Technology Data Exchange (ETDEWEB)

Tsay, Chien-Yie, E-mail: cytsay@fcu.edu.tw; Liang, Shan-Chien

2015-02-15

Highlights: • P-type Ga-doped SnO{sub 2} semiconductor films were prepared by sol-gel spin coating. • Optical bandgaps of the SnO{sub 2}:Ga films are narrower than that of the SnO{sub 2} film. • SnO{sub 2}:Ga films exhibited p-type conductivity as Ga doping content higher than 10%. • A p-n heterojunction composed of p-type SnO{sub 2}:Ga and n-type ZnO:Al was fabricated. - Abstract: P-type transparent tin oxide (SnO{sub 2}) based semiconductor thin films were deposited onto alkali-free glass substrates by a sol-gel spin-coating method using gallium (Ga) as acceptor dopant. In this study, we investigated the influence of Ga doping concentration ([Ga]/[Sn] + [Ga] = 0%, 5%, 10%, 15%, and 20%) on the structural, optical and electrical properties of SnO{sub 2} thin films. XRD analysis results showed that dried Ga-doped SnO{sub 2} (SnO{sub 2}:Ga) sol-gel films annealed in oxygen ambient at 520 °C for 1 h exhibited only the tetragonal rutile phase. The average optical transmittance of as-prepared thin film samples was higher than 87.0% in the visible light region; the optical band gap energy slightly decreased from 3.92 eV to 3.83 eV with increases in Ga doping content. Hall effect measurement showed that the nature of conductivity of SnO{sub 2}:Ga thin films changed from n-type to p-type when the Ga doping level was 10%, and when it was at 15%, Ga-doped SnO{sub 2} thin films exhibited the highest mean hole concentration of 1.70 × 10{sup 18} cm{sup -3}. Furthermore, a transparent p-SnO{sub 2}:Ga (Ga doping level of 15%)/n-ZnO:Al (Al doping level of 2%) heterojunction was fabricated on alkali-free glass. The I-V curve measurement for the p-n heterojunction diode showed a typical rectifying characteristic with a forward turn-on voltage of 0.65 V.

Synthesis and Characterization of V2O5/SiO2 Nanoparticles as Efficient Catalyst for Aromatization 1,4 Dihydropyridines

International Nuclear Information System (INIS)

Farzaneh, F.; Zamanifar, E.; Jafari Foruzin, L.; Ghandi, M.

2012-01-01

V 2 O 5 /SiO 2 nanoparticles was prepared via an one-pot sol gel method from vanadyl- acetylacetonate and tetraethyl orthosilicate in refluxing MeOH, followed by calcination at 700 °C for 2 hours. The resultant nanoparticles was characterized by means of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, TGA and FTIR techniques. Rapid and efficient aromatization of 1,4-dihydropyridines catalyzed by V 2 O 5 /SiO 2 nanoparticles is described in this presentation.

Thickness dependent electrical properties of CdO thin films prepared by spray pyrolysis method

International Nuclear Information System (INIS)

Murthy, L.C.S.; Rao, K.S.R.K.

1999-01-01

A large number of thin films of cadmium oxide have been prepared on glass substrates by spray pyrolysis method. The prepared films have uniform thickness varying from 200-600 nm and good adherence to the glass substrate. A systematic study has been made on the influence of thickness on resistivity, sheet resistance, carrier concentration and mobility of the films. The resistivity, sheet resistance, carrier concentration and mobility values varied from 1.56-5.72x10 -3 Ω-cm, 128-189 Ω/□, 1.6-3.9x10 21 cm -3 and 0.3-3 cm 2 /Vs, respectively for varying film thickness. A systematic increase in mobility with grain size clearly indicates the reduction of overall scattering of charge carriers at the grain boundaries. The large concentration of charge carriers and low mobility values have been attributed to the presence of Cd as an impurity in CdO microcrystallites. Using the optical transmission data, the band gap was estimated and found to vary from 2.20-2.42 eV. These films have transmittance around 77% and average reflectance is below 2.6% in the spectral range 350-850 nm. The films are n-type and polycrystalline in nature. SEM micrographs of the CdO films were taken and the films exhibit clear grains and grain boundary formation at a substrate temperature as low as 523 K. (author)

Investigations of structural, morphological and optical properties of Cu:ZnO/TiO2/ZnO and Cu:TiO2/ZnO/TiO2 thin films prepared by spray pyrolysis technique

Directory of Open Access Journals (Sweden)

M.I. Khan

Full Text Available The aim of this research work is presented a comparison study of Cu:ZnO/TiO2/ZnO (Cu:ZTZ and Cu:TiO2/ZnO/TiO2 (Cu:TZT thin films deposited by spray pyrolysis technique on FTO substrates. After deposition, these films are annealed at 500 °C. XRD confirms the anatase phase of TiO2 and Hexagonal wurtzite phase of ZnO. SEM shows that Cu:TZT has more porous surface than Cu:ZTZ and also the root mean square (RMS roughness of Cu:TZT film is 48.96 and Cu:ZTZ film is 32.69. The calculated optical band gaps of Cu:TZT and Cu:ZTZ thin films are 2.65 eV and 2.6 eV respectively, measured by UV–Vis spectrophotometer. This work provides an environment friendly and low cost use of an abundant material for highly efficient dye sensitized solar cells (DSSCs. Keywords: Multilayer films, ZnO, TiO2, Cu

CdSe/beta-Pb0.33V2O5 heterostructures: Nanoscale semiconductor interfaces with tunable energetic configurations for solar energy conversion and storage

Science.gov (United States)

Milleville, Christopher C.

charge transfer of CdSe/β-Pb0.33V¬2O5 and CdSe/V2O5 heterostructures. TA measurements indicate that, for both types of heterostructures, photoexcitation of CdSe QDs was followed by a transfer of electrons to the conduction band of β-Pb0.33V¬2O5 and holes to the mid-gap states of β-Pb0.33V¬2O5. Ultrafast transient absoprtion measurements revealed that holes actually transferred before electrons, on time scales of ca. 2 ps. In contrast, for analogous heterostructures consisting of CdSe QDs interfaced with V2O5, only electron transfer was observed. In addition, electron transfer was readily achieved for SILAR-prepared heterostructures; however, for LAA-prepared heterostructures, electron transfer was observed only upon excitation at energies substantially greater than the bandgap absorption threshold of CdSe. Transient absorbance decay traces revealed longer excited-state lifetimes (1-3 μs) for CdSe/β Pb0.33V2O5 heterostructures relative to bare β-Pb0.33V2O5 NWs (0.2 to 0.6 μs); the difference was attributed to surface passivation of intrinsic surface defects in β-Pb0.33V2O5 upon interfacing with CdSe. In an effort to improve the energetic offset in QD/β-Pb0.33V2O5 heterostructures, cadmium sulfide (CdS) QDs were used in place of CdSe QDs. X-ray photoelectron spectroscopy (XPS) valence band spectra of CdS/β-Pb0.33V2O5 and CdSe/β-Pb0.33V2O5 revealed a greater binding energy onset for CdS compared to CdSe. Binding energy onsets of 1.33 (± 0.03) and 0.92 (± 0.02) eV were determined for Cys-CdS/β Pb0.33V2O5 and Cys-CdSe/β Pb0.33V2O5, respectively; suggesting a 0.41 (±0.04) eV decrease in the free energy (ΔG) needed for hole transfer from the valence band edge of the QDs to the mid-gap states. Linear sweep voltammetry was employed to measure the photocatalytic activity of CdSe/β Pb0.33V2O5 heterostructures in electrolytes containing ascorbic acid as a sacrificial proton donor. Preliminary photoelectrochemical measurements on CdSe/β-Pb0.33V2O5 electrodes

Enhanced dielectric properties of ZrO2 thin films prepared in nitrogen ambient by pulsed laser deposition

International Nuclear Information System (INIS)

Zhu, J; Li, T L; Pan, B; Zhou, L; Liu, Z G

2003-01-01

ZrO 2 thin films were fabricated in O 2 ambient and in N 2 ambient by pulsed laser deposition (PLD), respectively. X-ray diffraction revealed that films prepared at 400 deg. C remained amorphous. The dielectric properties of amorphous ZrO 2 films were investigated by measuring the capacitance-frequency characteristics of Pt/ZrO 2 /Pt capacitor structures. The dielectric constant of the films deposited in N 2 ambient was larger than that of the films deposited in O 2 ambient. The dielectric loss was lower for films prepared in N 2 ambient. Atom force microscopy investigation indicated that films deposited in N 2 ambient had smoother surface than films deposited in O 2 ambient. Capacitance-voltage and current-voltage characteristics were studied. The equivalent oxide thickness (EOT) of films with 6.6 nm physical thickness deposited in N 2 ambient is lower than that of films deposited in O 2 ambient. An EOT of 1.38 nm for the film deposited in N 2 ambient was obtained, while the leakage current density was 94.6 mA cm -2 . Therefore, ZrO 2 thins deposited in N 2 ambient have enhanced dielectric properties due to the incorporation of nitrogen which leads to the formation of Zr-doped nitride interfacial layer, and is suggested to be a potential material for alternative high-k (high dielectric constant) gate dielectric applications

Fabrication and characterization of nanostructured anatase TiO{sub 2} films prepared by electrochemical anodization and their photocatalytic properties

Energy Technology Data Exchange (ETDEWEB)

Yurddaskal, Metin [Dokuz Eylul University, The Graduate School of Natural and Applied Sciences, Buca 35390, Izmir (Turkey); Dokuz Eylul University, Center for Fabrication and Applications of Electronic Materials (EMUM), Buca, 35390, Izmir (Turkey); Dikici, Tuncay, E-mail: tuncay.dikici@ikc.edu.tr [Dokuz Eylul University, The Graduate School of Natural and Applied Sciences, Buca 35390, Izmir (Turkey); Izmir Katip Celebi University, Department of Materials Science and Engineering, Cigli 35620, Izmir (Turkey); Yildirim, Serdar [Dokuz Eylul University, The Graduate School of Natural and Applied Sciences, Buca 35390, Izmir (Turkey); Dokuz Eylul University, Center for Fabrication and Applications of Electronic Materials (EMUM), Buca, 35390, Izmir (Turkey); Yurddaskal, Melis [Celal Bayar University, Department of Mechanical Engineering, Muradiye, 45140 Manisa (Turkey); Toparli, Mustafa; Celik, Erdal [Dokuz Eylul University, Center for Fabrication and Applications of Electronic Materials (EMUM), Buca, 35390, Izmir (Turkey); Dokuz Eylul University, Department of Metallurgical and Materials Engineering, Buca 35390, Izmir (Turkey)

2015-12-05

In this study, nanostructured anatase titanium dioxide (TiO{sub 2}) films were fabricated by electrochemical anodization of titanium first, and then annealed at 500 °C for 2 h. Effect of electrolyte concentration, anodization time and electrolyte temperature on the surface morphology of the resulting TiO{sub 2} thin films were investigated. The phase structures, surface morphology and chemical composition were analyzed using X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity tests of the samples were evaluated by the degradation of aqueous methylene blue (MB) solutions under UV light illumination for different periods of time. The results showed that the structure of nanostructured TiO{sub 2} films depended strongly on the anodization parameters. It was found that there were micro-scale pores (<10 μm) and nano-scale pores (diameter in the range from 40 to 70 nm) on the anodized titanium surfaces. This study indicated that structures, surface morphology, and surface area of the nanostructured anatase TiO{sub 2} films played an important role on their photocatalytic performance. The results clearly proved that nanostructured anatase TiO{sub 2} film prepared with optimum process parameters resulted in enhancement of the photocatalytic activity. - Highlights: • TiO{sub 2} thin films were prepared on titanium substrates by electrochemical anodization at 30 V. • Effect of various anodization parameters on the photocatalytic activity of titanium was investigated. • Micro- and nanoscale TiO{sub 2} pores formed on the titanium by anodizing. • Surface morphology of the TiO{sub 2} films plays an important role on the photocatalytic performance. • The sample anodized for 240 min showed the highest photocatalytic activity.

Investigation of growth, structural and electronic properties of V2O3 thin films on selected substrates

International Nuclear Information System (INIS)

Nateprov, Alexei

2006-08-01

The present work is devoted to the experimental study of the MI transition in V 2 O 3 thin films, grown on different substrates. The main goal of the work was to develop a technology of growth of V 2 O 3 thin films on substrates with different electrical and structural properties (diamond and LiNbO 3 ), designed for specific applications. The structural and electrical properties of the obtained films were characterized in detail with a special focus on their potential applications. The MIT of V 2 O 3 was investigated by SAW using first directly deposited V 2 O 3 thin film onto a LiNbO 3 substrate. (orig.)

The selectivity of catalysts composed of V/sub 2/O/sub 5/ supported on ZrO/sub 2/-Y/sub 2/O/sub 3/ mixed oxides for methanol oxidation

International Nuclear Information System (INIS)

VanOmmen, J.G.; Gellings, P.J.; Ross, J.R.H.

1988-01-01

V/sub 2/O/sub 5/ monolayer catalysts were prepared on ZrO/sub 2/ and ZrO/sub 2/ doped with Y/sub 2/O/sub 3/ by two methods. The coverages obtained are only half a monolayer and did not depend on the preparation method or type of support. The selectivity for oxidation of methanol over these V/sub 2/O/sub 5/ catalysts changes from a predominance of formaldehyde to a predominance of methyl formate when the support is doped with Y/sub 2/C/sub 3/, independent of the amount of Y/sub 2/O/sub 3/

Preparation and Properties of Nano Dy/TiO2 Films Supported on High Silica Fiber

Directory of Open Access Journals (Sweden)

HUANG Feng-ping

2017-07-01

Full Text Available In order to improve the photocatalytic degradation performance and stability of nano TiO2, Dy doped TiO2 supported on high silica glass fiber was prepared by microwave-sol method combined with dip-coating method. The samples were analyzed by XRD,SEM,PL,EDS,XPS and other equipments for phase composition of films,surface topography, surface elements and the stability of films. And the effects of pretreatment solution and coating method on the high-silica fiber film were investigated.In addition, the photocatalytic performance of the sample has been investigated by degrading methylene blue. The results show that the catalytic stability of Dy doping TiO2 nanofilms supported on high silica glass fiber can be improved and the degradation of methyl orange can reach 94% in 30min after 5 times of coating treatment.

Influences of annealing temperature on sprayed CuFeO2 thin films

Science.gov (United States)

Abdelwahab, H. M.; Ratep, A.; Abo Elsoud, A. M.; Boshta, M.; Osman, M. B. S.

2018-06-01

Delafossite CuFeO2 thin films were successfully prepared onto quartz substrates using simple spray pyrolysis technique. Post annealing under nitrogen atmosphere for 2 h was necessary to form delafossite CuFeO2 phase. The effect of alteration in annealing temperature (TA) 800, 850 and 900 °C was study on structural, morphology and optical properties. The XRD results for thin film annealed at TA = 850 °C show single phase CuFeO2 with rhombohedral crystal system and R 3 bar m space group with preferred orientation along (0 1 2). The prepared copper iron oxide thin films have an optical transmission ranged ∼40% in the visible region. The optical direct optical band gap of the prepared thin films was ranged ∼2.9 eV.

Photodegradative properties of TiO{sub 2} films prepared by MOCVD

Energy Technology Data Exchange (ETDEWEB)

Justicia, I.; Ayllon, J.A.; Figueras, A. [Consejo Superior de Investigaciones Cientificas, Barcelona (Spain). Inst. de Ciencia de Materiales; Battiston, G.A.; Gerbasi, R. [Consejo Superior de Investigaciones Cientificas, Barcelona (Spain). Inst. de Ciencia de Materiales; Ist. di Chimica e Tecnologie Inorganiche e dei Materiali Avanzati del CNR, Padova (Italy)

2001-08-01

TiO{sub 2} is a well-known photocatalyst for the air-oxydation of organic compounds. This paper deals with the preparation of TiO{sub 2} layers by MOCVD. The photodegradation rate has been studied in the presence of aqueous suspensions (methylene blue) as a function of the film thickness, roughness and crystallite preferred orientation. These results are compared with aqueous suspensions of Degussa P-25 powders. Deposits obtained on fused quartz showed a higher photodegradation rate than those prepared on glass, while Degussa powders exhibited an intermediate value. (orig.)

A short literature survey on iron and cobalt ion doped TiO2 thin films and photocatalytic activity of these films against fungi

International Nuclear Information System (INIS)

Tatlıdil, İlknur; Bacaksız, Emin; Buruk, Celal Kurtuluş; Breen, Chris; Sökmen, Münevver

2012-01-01

Highlights: ► Co or Fe doped TiO 2 thin films were prepared by sol–gel method. ► We obtained lower E g values for Fe-doped and Co-TiO 2 thin films. ► Doping greatly affected the size and shape of the TiO 2 nanoparticles. ► Photocatalytic killing effect of the doped TiO 2 thin films on C. albicans and A. niger was significantly higher than undoped TiO 2 thin film for short exposure periods. - Abstract: In this study, a short recent literature survey which concentrated on the usage of Fe 3+ or Co 2+ ion doped TiO 2 thin films and suspensions were summarized. Additionally, a sol–gel method was used for preparation of the 2% Co or Fe doped TiO 2 thin films. The surface of the prepared materials was characterised using scanning-electron microscopy (SEM) combined with energy dispersive X-ray (EDX) analysis and band gap of the films were calculated from the transmission measurements that were taken over the range of 190 and 1100 nm. The E g value was 3.40 eV for the pure TiO 2 , 3.00 eV for the Fe-doped TiO 2 film and 3.25 eV for Co-TiO 2 thin film. Iron or cobalt doping at lower concentration produce more uniformed particles and doping greatly affected the size and shape of the TiO 2 nanoparticles. Photocatalytic killing effect of the 2% Co doped TiO 2 thin film on Candida albicans was significantly higher than Fe doped TiO 2 thin film for short and long exposure periods. Doped thin films were more effective on Aspergillus niger for short exposure periods.

The effect of the film thickness and doping content of SnO2:F thin films prepared by the ultrasonic spray method

International Nuclear Information System (INIS)

Rahal Achour; Benramache Said; Benhaoua Boubaker

2013-01-01

This paper reports on the effects of film thickness and doping content on the optical and electrical properties of fluorine-doped tin oxide. Tin (II) chloride dehydrate, ammonium fluoride dehydrate, ethanol and HCl were used as the starting materials, dopant source, solvent and stabilizer, respectively. The doped films were deposited on a glass substrate at different concentrations varying between 0 and 5 wt% using an ultrasonic spray technique. The SnO 2 :F thin films were deposited at a 350 °C pending time (5, 15, 60 and 90 s). The average transmission was about 80%, and the films were thus transparent in the visible region. The optical energy gap of the doped films with 2.5 wt% F was found to increase from 3.47 to 3.89 eV with increasing film thickness, and increased after doping at 5 wt%. The decrease in the Urbach energy of the SnO 2 :F thin films indicated a decrease in the defects. The increase in the electrical conductivity of the films reached maximum values of 278.9 and 281.9 (Ω·cm) −1 for 2.5 and 5 wt% F, respectively, indicating that the films exhibited an n-type semiconducting nature. A systematic study on the influence of film thickness and doping content on the properties of SnO 2 :F thin films deposited by ultrasonic spray was reported. (semiconductor materials)

Soft chemistry routes to transparent metal oxide thin films. The case of sol–gel synthesis and structural characterization of Ta{sub 2}O{sub 5} thin films from tantalum chloromethoxide

Energy Technology Data Exchange (ETDEWEB)

Epifani, Mauro, E-mail: mauro.epifani@le.imm.cnr.it [Istituto per la Microelettronica e i Microsistemi, IMM-CNR, Via Monteroni, 73100 Lecce (Italy); Zamani, Reza [Catalonia Institute for Energy Research, IREC c/Jardins de les Dones de Negre, 1, 08930-Sant Adria del Besos, Barcelona (Spain); Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, 08193 Bellaterra, CAT (Spain); Arbiol, Jordi [Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, 08193 Bellaterra, CAT (Spain); Institucio Catalana de Recerca i Estudis Avançats, ICREA, 08010, Barcelona (Spain); Fabrega, Cristian; Andreu, Teresa [Catalonia Institute for Energy Research, IREC c/Jardins de les Dones de Negre, 1, 08930-Sant Adria del Besos, Barcelona (Spain); Pace, Giovanni Battista; Siciliano, Pietro [Istituto per la Microelettronica e i Microsistemi, IMM-CNR, Via Monteroni, 73100 Lecce (Italy); Morante, Joan R. [Catalonia Institute for Energy Research, IREC c/Jardins de les Dones de Negre, 1, 08930-Sant Adria del Besos, Barcelona (Spain); M2E-IN2UB-XaRMAE, Departament d’Electrònica, Universitat de Barcelona, C. Martí i Franquès 1, 08028 Barcelona, CAT (Spain)

2014-03-31

Ta{sub 2}O{sub 5} thin films were prepared by spin-coating methanol solutions of Ta chloromethoxide. It was prepared by reacting TaCl{sub 5} with methanol, followed by water addition (H{sub 2}O: Ta molar ratio was 16). Thin films were deposited by spin-coating onto SiO{sub 2}/Si substrates, followed by drying at 90 °C and heat-treatment up to 700 °C. The films were characterized by X-ray diffraction, transmission electron microscopy and field emission scanning electron microscopy. Crystallization was obtained only after heating at 700 °C, in the Ta{sub 2}O{sub 5} orthorhombic phase. The resulting films had a thickness of 100 nm. Their structure was constituted by porous crystals with size up to 50 nm, while the pores had a size of about 10 nm. The results demonstrated that TaCl{sub 5} is very convenient precursor for the wet chemical synthesis of Ta{sub 2}O{sub 5} thin films. - Highlights: • Development of convenient solution synthesis of Ta{sub 2}O{sub 5} thin films; • The precursor chemistry was established and related to the synthesis process; • Uniform films crystallized in the most stable orthorombic Ta{sub 2}O{sub 5} phase;.

Glass formation in AgI:Ag2O:V2O5 and AgI:Ag2O:(V2O5+B2O3) systems

International Nuclear Information System (INIS)

Kaushik, R.; Hariharan, K.

1988-01-01

Transport properties of glasses in the system AgI:Ag 2 O: V 2 O 5 and AgI:Ag 2 O: (V 2 O 5 +B 2 O 3 ) have ben investigated. It was found that, at high AgI concentrations, the addition of another glass former (B 2 O 3 ) did not improve the conduction characteristics of the pure vanadate glasses, the best conducting composition of which had ambient temperature, ionic conductivity comparable to that of conventional liquid electrolytes. The highest conducting composition was used as an electrolyte in the study of silver solid state cells. The discharge characteristics of different cells fabricated with the glassy electrolyte, have been compared with those having the best conducting polycrystalline ompositions as electrolytes. 11 refs.; 4 figs.; 1 table

Raman, FTIR, thermal and optical properties of TeO2-Nb2O5-B2O3-V2O5 quaternary glass system

Directory of Open Access Journals (Sweden)

Swapna

2017-07-01

Full Text Available A series of quaternary glass systems with the composition 79TeO2-(20−xNb2O5-xB2O3-1V2O5 was prepared using the melt quench technique. Such studies as optical absorption, Raman, FTIR spectroscopy, EPR and DSC were carried out on the glass system. The physical properties, such as density (ρ and molar volume (VM, were determined. The Urbach energy (ΔE, optical band gap (Eopt, optical basicity (Λ, refractive index (n and electron polarizability (α of the glasses were determined from optical absorption data. Spin-Hamiltonian parameters of VO2+ ions were calculated from the EPR data. With the gradual substitution of B2O3 at the expense of Nb2O5, the density and optical band gap of the glasses decreased, and the electronic polarizability increased. EPR spectra revealed that VO2+ occupies an octahedral site with tetrahedral compression. Spin-Hamiltonian parameters g|| and g⊥ increased as B2O3 content increased in the glass. The glass transition temperature (Tg also decreased as the B2O3 content in the glass increased.

Structural and electrical characteristics of high-κ Er2O3 and Er2TiO5 gate dielectrics for a-IGZO thin-film transistors.

Science.gov (United States)

Chen, Fa-Hsyang; Her, Jim-Long; Shao, Yu-Hsuan; Matsuda, Yasuhiro H; Pan, Tung-Ming

2013-01-08

In this letter, we investigated the structural and electrical characteristics of high-κ Er2O3 and Er2TiO5 gate dielectrics on the amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) devices. Compared with the Er2O3 dielectric, the a-IGZO TFT device incorporating an Er2TiO5 gate dielectric exhibited a low threshold voltage of 0.39 V, a high field-effect mobility of 8.8 cm2/Vs, a small subthreshold swing of 143 mV/decade, and a high Ion/Ioff current ratio of 4.23 × 107, presumably because of the reduction in the oxygen vacancies and the formation of the smooth surface roughness as a result of the incorporation of Ti into the Er2TiO5 film. Furthermore, the reliability of voltage stress can be improved using an Er2TiO5 gate dielectric.

Structure of the T cell receptor in a Ti alpha V beta 2, alpha V beta 8-positive T cell line

DEFF Research Database (Denmark)

Hou, X; Dietrich, J; Kuhlmann, J

1994-01-01

not known; however, it has been suggested that each TcR contains two Ti dimers. To gain insight into the structure of the TcR we constructed a Ti alpha V beta 2, alpha V beta 8-positive T cell line which expressed the endogenous human TiV beta 8 and the transfected mouse TiV beta 2 both in association......The T cell receptor (TcR) is composed of at least six different polypeptide chains consisting of the clonotypic Ti heterodimer (Ti alpha beta or Ti gamma delta) and the noncovalently associated CD3 chains (CD3 gamma delta epsilon zeta). The exact number of subunits constituting the TcR is still...... with the endogenous Ti alpha and CD3 chains at the cell surface. Preclearing experiments with radioiodinated cell lysate prepared with digitonin lysis buffer demonstrated that depleting the lysate of Ti alpha V beta 8 by immunoprecipitation with anti V beta 8 monoclonal antibody (mAb) did not reduce the amount of Ti...

Thin film fabrication and transport properties of the heavy Fermion oxide LiV{sub 2}O{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Niemann, Ulrike [Max Planck Institute for Solid State Research, Stuttgart (Germany); Hirai, Daigorou [University of Tokyo, Tokyo (Japan); Takagi, Hidenori [Max Planck Institute for Solid State Research, Stuttgart (Germany); University of Tokyo, Tokyo (Japan); Institute for Functional Matter and Quantum Technologies, University of Stuttgart, Stuttgart (Germany)

2016-07-01

The spinel compound LiV{sub 2}O{sub 4} is well-known for its heavy fermion behaviour, although it contains no f-electron bands. This unexpected behaviour has been a subject of several studies, but the origin of it is still not fully understood. In this study, we successfully fabricated single crystalline epitaxial thin film of LiV{sub 2}O{sub 4} on SrTiO{sub 3}, LSAT and MgO substrates, using a pulsed laser deposition technique. By changing film thickness and substrate materials, dimensionality and epitaxial strain was controlled. The formation of an epitaxially grown LiV{sub 2}O{sub 4} phase has been confirmed by X-ray diffraction measurements. LiV{sub 2}O{sub 4} films on MgO were found to be strained, due to the small lattice mismatch, in contrast to fully relaxed films on SrTiO{sub 3}.The heavy fermion behaviour of bulk LiV{sub 2}O{sub 4} at low temperatures is well reproduced in thick enough (∼ 7 nm) films on SrTiO{sub 3} substrates. In contrast, an insulating phase was found in strained LiV{sub 2}O{sub 4} thin films on MgO substrates, revealing the key role of the lattice in stabilising the metallic ground state. In this presentation, we discuss the thin film fabrication and the effect of epitaxial strain on heavy fermion behaviour in LiV{sub 2}O{sub 4}.

Conversion of 2-deoxy-D-ribose into 2-amino-5-(2-deoxy-beta-D-ribofuranosyl)pyridine, 2'-deoxypseudouridine, and other C-(2'-deoxyribonucleosides).

Science.gov (United States)

Reese, Colin B; Wu, Qinpei

2003-09-21

The synthesis of 2-amino-5-(2-deoxy-beta-D-ribofuranosyl)pyridine 2a, 2-amino-5-(2-deoxy-alpha-D-ribofuranosyl)-pyridine 23, 2-amino-5-(2-deoxy-beta-D-ribofuranosyl)-3-methylpyridine 2b, 2-amino-5-(2-deoxy-alpha-D-ribofuranosyl)-3-methylpyridine 29 and 5-(2-deoxy-beta-D-ribofuranosyl)-2,4-dioxopyrimidine [2'-deoxypseudouridine] 30a is described. These C-nucleosides are prepared either from 2-deoxy-3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-ribofuranose 15 or from 2-deoxy-3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-ribono-1,4-lactone 16, which are themselves prepared from 2-deoxy-D-ribose 13. The sugar derivatives are first allowed to react with the appropriate 5-lithio-pyridine or 5-lithio-pyrimidine derivatives, which are prepared from 5-bromo-2-(dibenzylamino)pyridine 12a, 5-bromo-2-[bis(4-methoxybenzyl)amino]pyridine 12b, 5-bromo-2-dibenzylamino-3-methylpyridine 25 and 5-bromo-2,4-bis(4-methoxybenzyloxy)pyrimidine 33. The products from the reactions between the lithio-derivatives and the lactol 15 are cyclized under Mitsunobu conditions; the products from the reactions between the lithio-derivatives and the lactone 16 are first reduced with L-Selectride before cyclization, also under Mitsunobu conditions. In all cases, the beta-anomers of the protected C-nucleosides are the predominant products. Finally, the separation of the alpha- and beta-anomers and the removal of all of the protecting groups are described.

Sol–gel preparation of well-adhered films and long range ordered inverse opal films of BaTiO{sub 3} and Bi{sub 2}Ti{sub 2}O{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Al-Arjan, Wafa S. [Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); King Faisal University, PO Box 380, Al Hofuf (Saudi Arabia); Algaradah, Mohammed M.F. [Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); King Khalid College, Riyadh (Saudi Arabia); Brewer, Jack [Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Hector, Andrew L., E-mail: a.l.hector@soton.ac.uk [Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom)

2016-02-15

Highlights: • Highly adaptable sols are presented for processing of the electroceramic materials BaTiO{sub 3} and Bi{sub 2}Ti{sub 2}O{sub 7}. • High quality thin films are produced by dip coating with good phase control. • Infiltration of cross-linked polystyrene templates led to high quality inverse opals. - Abstract: Barium and bismuth titanate thin films and well-ordered inverse opal films are produced by dip coating from sols containing titanium alkoxides with acetic acid, acetylacetone, methoxyethanol and water. The inverse opal preparations used crosslinked polystyrene opal templates. Heat treatment in air produced tetragonal BaTiO{sub 3} or mixtures of the hexagonal and tetragonal phases, or phase pure Bi{sub 2}Ti{sub 2}O{sub 7}. Good quality films were obtained with a thickness of 5 μm from a single dipping, and the thickness could be increased by dipping multiple times. Inverse opals were well ordered and exhibited opalescence and photonic stop band effects.

D-, O- and OD- desorption induced by low-energy (0-20 eV) electron impact on amorphous D2O films

International Nuclear Information System (INIS)

Pan Xiaoning; Abdoul-Carime, Hassan; Cloutier, Pierre; Bass, Andrew D.; Sanche, Leon

2005-01-01

We report measurements of low-energy electron stimulated desorption of D - , O - and OD - anions from multilayer amorphous D 2 O films physisorbed on a Pt substrate. The 0-20 eV incident energy dependence (i.e., the yield function) of the desorbed D - yield reveals the presence of a strong peak located at 7.2 eV with a shoulder near 9 eV, which are due to dissociation of the transient states 2 B 1 and 2 A 1 of D 2 O, respectively. The O - and OD - yield functions each exhibit a single broad structure between 5 and 12 eV which also result from dissociative electron attachment (DEA). Due to the weakness of the O - and OD - signals, three possible processes involving DEA must be considered to explain their yield functions, i.e., direct DEA, reactive scattering and DEA to a new product in the film synthesized by the electron beam. It is concluded that at large electron doses (>7.5x10 14 electrons/cm 2 ), these broad peaks arise from DEA to a new product, whereas at lower dose the possibility of direct DEA (i.e., e - +D 2 O→D 2 O - →O - +D 2 and OD - +D) cannot be entirely discounted. Above 15 eV, all anion yield functions exhibit a monotonic rise due to direct dipolar dissociation

Preparation and characterization of TiO[sub 2]/Sb thin films for solar energy applications

Energy Technology Data Exchange (ETDEWEB)

Badawy, W.A. (Dept. of Chemistry, Cairo Univ., Giza (Egypt))

1993-01-01

Pure and antimony-incorporated TiO[sub 2] thin films were prepared using a spray-CVD method. The method allows for convenient incorporation of foreign atoms into the oxide matrix during film growth. The foreign atoms in the oxide film affects both the photovoltaic and photoelectrochemical properties of the n-Si/oxide heterojunction. The characteristics of the prepared oxide films were affected significantly by the presence of antimony on the oxide matrix. The increased conductivity of the Sb-containing oxide layers is reflected in the improved photovoltaic properties of the prepared n-Si/TiO[sub 2]-Sb heterojunctions, e.g. fill factor and solar conversion efficiency. The photoelectrochemical properties of the prepared devices revealed that the charge transfer step at the oxide/electrolyte interface leads to a deterioration of the cell quality. However, this drawback has been offset by the improved properties of the heterojunction. (orig.)

Shielding behavior of V2O5 doped lead borate glasses towards gamma irradiation

International Nuclear Information System (INIS)

Ghoneim, N.A.; ElBatal, H.A.; Abdelghany, A.M.; Ali, I.S.

2011-01-01

Highlights: → Base lead borate glass together with samples of the same composition doped with varying V 2 O 5 contents were prepared. → UV-visible and infrared spectroscopy were measured before and after successive gamma irradiation. → Glass samples are observed to absorb strongly in the UV. → Infrared absorption spectra indicate the presence of both triangular and tetrahedral borate groups besides the sharing of lead ions in network forming and network modifying sites. - Abstract: Undoped lead borate glass of the composition PbO 70%-B 2 O 3 30% together with samples of the same composition and doped with varying V 2 O 5 contents were prepared. UV-visible absorption spectra were measured out in the range 200-1500 nm before and after successive gamma irradiation. Infrared absorption measurements within the range 4000-400 cm -1 were carried out for the undoped and V 2 O 5 doped samples before gamma irradiation and after being irradiated with a dose of 6 Mrad. All the glass samples are observed to absorb strongly in the UV region due to the combined contributions of absorption due to trace iron impurities and that from the divalent lead Pb 2+ ions. The V 2 O 5 -doped glasses reveal extra visible absorption bands which are attributed to the existence of V 3+ ions in measurable content but not neglecting the other valence states of vanadium ions (V 4+ , V 5+ ). Infrared absorption spectra indicate the presence of both triangular and tetrahedral borate groups besides the sharing of lead ions in network forming and network modifying sites.

The Effect of Acidic and Redox Properties of V2O5/CeO2-ZrO2 Catalysts in Selective Catalytic Reduction of NO by NH3

DEFF Research Database (Denmark)

Putluru, Siva Sankar Reddy; Riisager, Anders; Fehrmann, Rasmus

2009-01-01

V2O5 supported ZrO2 and CeO2–ZrO2 catalysts were prepared and characterized by N2 physisorption, XRPD, TPR, and NH3-TPD methods. The influence of calcination temperature from 400 to 600 °C on crystallinity, acidic and redox properties were studied and compared with the catalytic activity...... in the selective catalytic reduction (SCR) of NO with ammonia. The surface area of the catalysts decreased gradually with increasing calcination temperature. The SCR activity of V2O5/ZrO2 catalysts was found to be related with the support crystallinity, whereas V2O5/CeO2–ZrO2 catalysts were also dependent...... on acidic and redox properties of the catalyst. The V2O5/CeO2–ZrO2 catalysts showed high activity and selectivity for reduction of NO with NH3....

Fabrication and photoelectrochemical properties of ZnS/Au/TiO2 nanotube array films.

Science.gov (United States)

Zhu, Yan-Feng; Zhang, Juan; Xu, Lu; Guo, Ya; Wang, Xiao-Ping; Du, Rong-Gui; Lin, Chang-Jian

2013-03-21

A highly ordered TiO(2) nanotube array film was fabricated by an anodic oxidation method. The film was modified by Au nanoparticles (NPs) formed by a deposition-precipitation technique and was covered with a thin ZnS shell prepared by a successive ionic layer adsorption and reaction (SILAR) method. The photoelectrochemical properties of the prepared ZnS/Au/TiO(2) composite film were evaluated by incident photon-to-current conversion efficiency (IPCE), and photopotential and electrochemical impedance spectroscopy (EIS) measurements under white light illumination. The results indicated that the Au NPs could expand the light sensitivity range of the film and suppress the electron-hole recombination, and the ZnS shell could inhibit the leakage of photogenerated electrons from the surface of Au NPs to the ZnS/electrolyte interface. When the 403 stainless steel in a 0.5 M NaCl solution was coupled to the ZnS/Au/TiO(2) nanotube film photoanode under illumination, its potential decreased by 400 mV, showing that the composite film had a better photocathodic protection effect on the steel than that of a pure TiO(2) nanotube film.

Ion beam modification of TiO2 films prepared by Cat-CVD for solar cell

International Nuclear Information System (INIS)

Narita, Tomoki; Iida, Tamio; Ogawa, Shunsuke; Mizuno, Kouichi; So, Jisung; Kondo, Akihiro; Yoshida, Norimitsu; Itoh, Takashi; Nonomura, Shuichi; Tanaka, Yasuhito

2008-01-01

The effects of nitrogen ion bombardment on TiO 2 films prepared by the Cat-CVD method have been studied to improve the optical and electrical properties of the material for use in Si thin film solar cells. The refractive index n and the dark conductivity of the TiO 2 film increased with irradiation time. The refractive index n of the TiO 2 film was changed from 2.1 to 2.4 and the electrical conductivity was improved from 3.4 x 10 -2 to 1.2 x 10 -1 S/cm by the irradiation. These results are due to the formation of Ti-N bonds and oxygen vacancies in the film

Swift heavy ion irradiated SnO{sub 2} thin film sensor for efficient detection of SO{sub 2} gas

Energy Technology Data Exchange (ETDEWEB)

Tyagi, Punit; Sharma, Savita [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Tomar, Monika [Department of Physics, Miranda House, University of Delhi, Delhi 110007 (India); Singh, Fouran [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi 110067 (India); Gupta, Vinay, E-mail: drguptavinay@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

2016-07-15

Highlights: • Response of Ni{sup 7+} ion irradiated (100 MeV) SnO{sub 2} film have been performed. • Effect of irradiation on the structural and optical properties of SnO{sub 2} film is studied. • A decrease in operating temperature and increased response is seen after irradiation. - Abstract: Gas sensing response studies of the Ni{sup 7+} ion irradiated (100 MeV) and non-irradiated SnO{sub 2} thin film sensor prepared under same conditions have been performed towards SO{sub 2} gas (500 ppm). The effect of irradiation on the structural, surface morphological, optical and gas sensing properties of SnO{sub 2} thin film based sensor have been studied. A significant decrease in operating temperature (from 220 °C to 60 °C) and increased sensing response (from 1.3 to 5.0) is observed for the sample after irradiation. The enhanced sensing response obtained for the irradiated SnO{sub 2} thin film based sensor is attributed to the desired modification in the surface morphology and material properties of SnO{sub 2} thin film by Ni{sup 7+} ions.

MeV ion irradiation induced evolution of morphological, structural and optical properties of nanostructured SnO2 thin films

International Nuclear Information System (INIS)

Mohapatra, Satyabrata; Bhardwaj, Neha; Pandey, Akhilesh

2015-01-01

Nanostructured SnO 2 thin films were prepared by carbothermal evaporation method. Morphological, structural and optical properties of the SnO 2 thin films, before and after 8 MeV Si ion irradiation to fluences varying from 1 × 10 13 to 1 × 10 15 ions cm −2 , were well characterized using atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), x-ray diffraction (XRD), Raman spectroscopy and photoluminescence spectroscopy (PL). XRD studies revealed the presence of SnO 2 and Sn nanoparticles in the as-deposited samples. AFM and FESEM studies on the irradiated samples revealed formation of nanoring-like structures, at a fluence of 1 × 10 15 ions cm −2 , with a central hole and circular rim consisting of nearly monodisperse SnO 2 nanoparticles. PL studies revealed strong enhancement in UV emissions upon 8 MeV Si ion irradiation. A growth mechanism underlying the formation of SnO 2 nanorings involving self-assembly of SnO 2 nanoparticles around nanoholes is tentatively proposed. (paper)

Structural and magnetic anisotropy in the epitaxial FeV2O4 (110) spinel thin films

Science.gov (United States)

Shi, Xiaolan; Wang, Yuhang; Zhao, Kehan; Liu, Na; Sun, Gaofeng; Zhang, Liuwan

2015-11-01

The epitaxial 200-nm-thick FeV2O4(110) films on (110)-oriented SrTiO3, LaAlO3 and MgAl2O4 substrates were fabricated for the first time by pulsed laser deposition, and the structural, magnetic, and magnetoresistance anisotropy were investigated systematically. All the films are monoclinic, whereas its bulk is cubic. Compared to FeV2O4 single crystals, films on SrTiO3 and MgAl2O4 are strongly compressively strained in [001] direction, while slightly tensily strained along normal [110] and in-plane [ 1 1 ¯ 0 ] directions. In contrast, films on LaAlO3 are only slightly distorted from cubic. The magnetic hard axis is in direction, while the easier axis is along normal [110] direction for films on SrTiO3 and MgAl2O4, and in-plane [ 1 1 ¯ 0 ] direction for films on LaAlO3. Magnetoresistance anisotropy follows the magnetization. The magnetic anisotropy is dominated by the magnetocrystalline energy, and tuned by the magneto-elastic coupling.

Photoelectrochemical response and corrosion behavior of CdS/TiO2 nanocomposite films in an aerated 0.5 M NaCl solution

Science.gov (United States)

Boonserm, Aleena; Kruehong, Chaiyaput; Seithtanabutara, Varinrumpai; Artnaseaw, Apichart; Kwakhong, Panomkorn

2017-10-01

This research aimed to investigate the photoelectrochemical response and corrosion behavior of CdS/TiO2 nanocomposite films using electrochemical measurements in an aerated 0.5 M NaCl solution under white light illumination. The CdS/TiO2 nanocomposite films were prepared by chemical bath deposition technique in a solution of cadmium and sulfide ions. The high resolution images of CdS/TiO2 nanocomposite films were provided by field emission scanning electron microscope. Theirs chemical identification and quantitative compositional information, crystallinity and actual chemical compounds formed were determined by energy dispersive spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy, respectively. The results indicated that the photoelectrochemical activity of the films depended strongly on CdS content. From the preparation of CdS/TiO2 nanocomposite films by 5, 10 and 15 dipping cycles in the chemical solutions, the best photoelectrochemical response was revealed by the 10 dipping cycles-prepared film. Galvanic couple testing demonstrated that the photoelectrochemical response of the film decreased continuously compared to that of anodized nanoporous TiO2 substrate which described by photocorrosion of CdS nanoparticles. In addition, chloride-ion attack also induced pitting corrosion leading to fluctuation and deterioration of photoelectrochemical response. CdO2 and Cd(OH)2 depositions were found as the main photocorrosion products on collapsed nanostructured-surface. The relevance between photoelectrochemical response and corrosion behavior of CdS/TiO2 nanocomposite film was discussed in detail.

Nanostructured Cu2O thin film electrodes prepared by electrodeposition for rechargeable lithium batteries

International Nuclear Information System (INIS)

Bijani, S.; Gabas, M.; Martinez, L.; Ramos-Barrado, J.R.; Morales, J.; Sanchez, L.

2007-01-01

Uniform films of Cu 2 O with thickness below 1 μm were prepared from a Cu(II) lactate solution. The deposits were compact and of high purity with the particle size varying from 60 to 400 nm. They were tested as electrodes in lithium batteries and their electrochemical response was consistent with the Cu 2 O + 2e - + 2Li + ↔ 2Cu + Li 2 O reaction. Nevertheless, the reversibility of this reaction was dependent on thickness. Kinetic factors associated with the poor electronic conductivity of Cu 2 O could account for the relevance of the influence of film thickness. The thinnest film, about 300 nm thick, exhibited the best electrochemical performance by sustaining a specific capacity as high as 350 Ah kg -1

n-Type Conductivity of Cu2O Thin Film Prepared in Basic Aqueous Solution Under Hydrothermal Conditions

Science.gov (United States)

Ursu, Daniel; Miclau, Nicolae; Miclau, Marinela

2018-03-01

We report for the first time in situ hydrothermal synthesis of n-type Cu2O thin film using strong alkaline solution. The use of copper foil as substrate and precursor material, low synthesis temperature and short reaction time represent the arguments of a new, simple, inexpensive and high field synthesis method for the preparation of n-type Cu2O thin film. The donor concentration of n-type Cu2O thin film obtained at 2 h of reaction time has increased two orders of magnitude than previous reported values. We have demonstrated n-type conduction in Cu2O thin film prepared in strong alkaline solution, in the contradiction with the previous works. Based on experimental results, the synthesis mechanism and the origin of n-type photo-responsive behavior of Cu2O thin film were discussed. We have proposed that the unexpected n-type character could be explained by H doping of Cu2O thin film in during of the hydrothermal synthesis that caused the p-to-n conductivity-type conversion. Also, this work raises new questions about the origin of n-type conduction in Cu2O thin film, the influence of the synthesis method on the nature of the intrinsic defects and the electrical conduction behavior.

Setting of an experimental simple technique for the realization of Ni2V2O7 thin films

International Nuclear Information System (INIS)

Baba, Ali E.; Bernede, J.C.; Zoaeter, M.

1999-01-01

Full text.Ni/V/Ni/V..../Ni/V/Ni thin layers were sequentially deposited in the atomic ratio Ni/V=1.Ni and V were deposited by an electron beam. The samples were annealed half an hour at 863K in room atmosphere. The films were characterized by x-ray diffraction, x-ray photoelectron spectroscopy (XPS), scanning electron microscopy and microprobe analysis. The results obtained, by comparison with those obtained on a reference powder, show that Ni 2 V 2 O 7 thin films crystallized in the monoclinic structure P21/c layer. Since SnO 2 is transparent conductive oxide this is very promising for the use of such oxides as negative electrode in thin film batteries

Crystallization of Sr0.5Ba0.5Nb2O6 Thin Films on LaNiO3 Electrodes by RF Magnetron Reactive Sputtering

Science.gov (United States)

Jong, Chao-An; Gan, Jon-Yiew

2000-02-01

Strontium barium niobium (Sr0.5Ba0.5Nb2O6) (SBN) thin films are prepared on conductive-oxide LNO (LaNiO3) electrodes by the rf magnetron sputtering system. Instead of conventional furnace annealing, SBN thin films are crystallized by rapid thermal annealing (RTA) above 700°C for 5 min. The textured SBN films are crystallized with two orientations: one is the (001) or (310) direction, and the other is the (002) or (620) direction. Films compositions measured by the electron spectroscopy of chemical analysis (ESCA) quantitative analysis method show nearly the same stoichiometric ratio as the target. The depth profiles of SBN films and the target are examined by secondary ion mass spectrometer (SIMS). The concentrations of the films are quite uniform. After being heat treated at 800°C for 5 min by RTA, La and Ni diffuse into the SBN film. The diffusion coefficient of La in SBN films is also calculated.

Preparation, Characterization and Thermal Degradation of Polyimide (4-APS/BTDA/SiO2 Composite Films

Directory of Open Access Journals (Sweden)

Arash Dehzangi

2012-04-01

Full Text Available Polyimide/SiO2 composite films were prepared from tetraethoxysilane (TEOS and poly(amic acid (PAA based on aromatic diamine (4-aminophenyl sulfone (4-APS and aromatic dianhydride (3,3,4,4-benzophenonetetracarboxylic dianhydride (BTDA via a sol-gel process in N-methyl-2-pyrrolidinone (NMP. The prepared polyimide/SiO2 composite films were characterized using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, scanning electron microscope (SEM and thermogravimetric analysis (TGA. The FTIR results confirmed the synthesis of polyimide (4-APS/BTDA and the formation of SiO2 particles in the polyimide matrix. Meanwhile, the SEM images showed that the SiO2 particles were well dispersed in the polyimide matrix. Thermal stability and kinetic parameters of the degradation processes for the prepared polyimide/SiO2 composite films were investigated using TGA in N2 atmosphere. The activation energy of the solid-state process was calculated using Flynn–Wall–Ozawa’s method without the knowledge of the reaction mechanism. The results indicated that thermal stability and the values of the calculated activation energies increased with the increase of the TEOS loading and the activation energy also varied with the percentage of weight loss for all compositions.

Room temperature inorganic polycondensation of oxide (Cu2O and ZnO) nanoparticles and thin films preparation by the dip-coating technique

International Nuclear Information System (INIS)

Salek, G.; Tenailleau, C.; Dufour, P.; Guillemet-Fritsch, S.

2015-01-01

Oxide thin solid films were prepared by dip-coating into colloidal dispersions of oxide nanoparticles stabilized at room temperature without the use of chelating or complex organic dispersing agents. Crystalline oxide nanoparticles were obtained by inorganic polycondensation and characterized by X-ray diffraction and field emission gun scanning electron microscopy. Water and ethanol synthesis and solution stabilization of oxide nanoparticle method was optimized to prepare two different structural and compositional materials, namely Cu 2 O and ZnO. The influence of hydrodynamic parameters over the particle shape and size is discussed. Spherical and rod shape nanoparticles were formed for Cu 2 O and ZnO, respectively. Isoelectric point values of 7.5 and 8.2 were determined for cuprous and zinc oxides, respectively, after zeta potential measurements. A shear thinning and thixotropic behavior was observed in both colloidal sols after peptization at pH ~ 6 with dilute nitric acid. Every colloidal dispersion stabilized in a low cost and environmentally friendly azeotrope solution composed of 96 vol.% of ethanol with water was used for the thin film preparation by the dip-coating technique. Optical properties of the light absorber cuprous oxide and transparent zinc oxide thin solid films were characterized by means of transmittance and reflectance measurements (300–1100 nm). - Highlights: • Room temperature inorganic polycondensation of crystalline oxides • Water and ethanol synthesis and solution stabilization of oxide nanoparticles • Low cost method for thin solid film preparation

Facile chemical synthesis of nanoporous layered δ-MnO{sub 2} thin film for high-performance flexible electrochemical capacitors

Energy Technology Data Exchange (ETDEWEB)

Hu, Yu; Wang, Jun; Jiang, Xionghua; Zheng, Yanfeng [The Key Laboratory of Low-Carbon Chemistry and Energy Conservation of Guangdong Province, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Chen, Zhenxing, E-mail: chenzx65@mail.sysu.edu.cn [The Key Laboratory of Low-Carbon Chemistry and Energy Conservation of Guangdong Province, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

2013-04-15

Layered δ-MnO{sub 2} thin films with a three-dimensional nanostructure are successfully fabricated on stainless steel foil substrates for flexible electrochemical capacitors by a facile and effective chemical bath deposition technology from ethanol and potassium permanganate solution at 15 °C. The as-prepared thin films display nanoporous morphology and a water contact angle of 20°. Energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy analyses reveal that the thin films are composed of δ-MnO{sub 2}. Electrochemical data demonstrate that the δ-MnO{sub 2} thin film electrodes can deliver a high special capacitance of 447 F/g at 2 mV/s, and provide a good capacitance retention ratio of 87% after 1000 continuous cycles at 10 mV/s in 0.5 M Na{sub 2}SO{sub 4}. Compressive and tensile bending tests show that the as-prepared electrodes can steadily work over a wide range of applied curvatures between −2.5 cm{sup −1} (tension) and 2.5 cm{sup −1} (compression). Only a small decrease in special capacitance (0.9% at a curvature of 2.5 cm{sup −1} under compressive strain, or 1.2% at a curvature of −2.5 cm{sup −1} under tensile strain) is observed even after bending for 200 cycles, indicating the excellent mechanical flexibility and electrochemical stability of the δ-MnO{sub 2} thin film electrodes.

Structural and morphological properties of HfxZr 1-xO2 thin films prepared by Pechini route

KAUST Repository

García-Cerda, L. A.

2010-03-01

In this study, HfxZr1-xO2 (0 < x < 1) thin films were deposited on silicon wafers using a dip-coating technique and by using a precursor solution prepared by the Pechini route. The effects of annealing temperature on the structure and morphological properties of the proposed films were investigated. HfxZr1-xO2 thin films with 1, 3 and 5 layers were annealed in air for 2 h at 600 and 800 °C and the structural and morphological properties studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results show that the films have monoclinic and tetragonal structure depending of the Hf and Zr concentration. SEM photographs show that all films consist of nanocrystalline grains with sizes in the range of 6 - 13 nm. The total film thickness is about 90 nm. © (2010) Trans Tech Publications.

Heteropoly acid promoted V2O5/TiO2 catalysts for NO abatement with ammonia in alkali containing flue gases

DEFF Research Database (Denmark)

Putluru, Siva Sankar Reddy; Jensen, Anker Degn; Riisager, Anders

2011-01-01

V2O5/TiO2 and heteropoly acid promoted V2O5/TiO2 catalysts were prepared and characterized by N2 physisorption, XRPD and NH3-TPD. The influence of the calcination temperature from 400 to 700 1C on crystallinity and acidic properties was studied and compared with the activity for the selective...... catalytic reduction (SCR) of NO with ammonia. The SCR activity of heteropoly acid promoted catalysts was found to be much higher than for unpromoted catalysts. The stability of heteropoly acid promoted catalysts is dependent on calcination temperature and there is a gradual decrease in SCR activity...... and acidity with increase in calcination temperatures. Furthermore, the heteropoly acid promoted V2O5/TiO2 catalysts showed excellent alkali deactivation resistance and might therefore be alternative deNOx catalysts in biomass fired power plants....

Preparation of epitaxial YBa2Cu3O7-y films on CeO2-buffered yttria-stabilized zirconia substrates by fluorine-free metalorganic deposition

International Nuclear Information System (INIS)

Tsukada, Kenichi; Yamaguchi, Iwao; Sohma, Mitsugu; Kondo, Wakichi; Kamiya, Kunio; Kumagai, Toshiya; Manabe, Takaaki

2007-01-01

Epitaxial YBa 2 Cu 3 O 7-y (YBCO) films of 120-550 nm thickness have been prepared by fluorine-free metalorganic deposition using a metal acetylacetonate-based coating solution on yttria-stabilized zirconia (YSZ) substrates with an evaporated CeO 2 buffer layer. The YBCO films were highly (0 0 1)-oriented by X-ray diffraction θ-2θ scanning and φ scanning. The YBCO films 120-400 nm in thickness demonstrated high critical current densities (J c ) with an average in excess of 3 MA/cm 2 at 77 K using an inductive method. In particular, a 210-nm-thick film showed a J c of 4.5 MA/cm 2 . These excellent properties are attributed to the high crystallinity, small in-plane fluctuation due to high epitaxy and to the microstructure free from grain boundaries in the YBCO films. Further increase of film thickness increased the fraction of irregularities, i.e., precipitates and micropores, in the film surfaces, resulting in lower J c values

Photocatalytic properties of porous TiO2/Ag thin films

International Nuclear Information System (INIS)

Chang, C.-C.; Chen, J.-Y.; Hsu, T.-L.; Lin, C.-K.; Chan, C.-C.

2008-01-01

In this study, nanocrystalline TiO 2 /Ag composite thin films were prepared by a sol-gel spin-coating technique. By introducing polystyrene (PS) spheres into the precursor solution, porous TiO 2 /Ag thin films were prepared after calcination at a temperature of 500 deg. C for 4 h. Three different sizes (50, 200, and 400 nm) of PS spheres were used to prepare porous TiO 2 films. The as-prepared TiO 2 and TiO 2 /Ag thin films were characterized by X-ray diffractometry (XRD) and by scanning electron microscopy to reveal structural and morphological differences. In addition, the photocatalytic properties of these films were investigated by degrading methylene blue under UV irradiation. When PS spheres of different sizes were introduced after calcination, the as-prepared TiO 2 films exhibited different porous structures. XRD results showed that all TiO 2 /Ag films exhibited a major anatase phase. The photodegradation of porous TiO 2 thin films prepared with 200 nm PS spheres and doped with 1 mol% Ag exhibited the best photocatalytic efficiency where ∼ 100% methylene blue was decomposed within 8 h under UV exposure

Structural and magnetic properties in Mn-doped ZnO films prepared by pulsed-laser deposition

International Nuclear Information System (INIS)

Li, Qiang; Wang, Yuyin; Liu, Jiandang; Kong, Wei; Ye, Bangjiao

2014-01-01

We investigated the structural and magnetic properties of Zn 0.95 Mn 0.05 O films prepared on sapphire substrates by pulsed-laser deposition. Only low temperature ferromagnetism (Curie temperature lower than 50 K) was observed in Mn-doped samples, while pure ZnO film shows a typical paramagnetic behavior. Structural analyses indicate that the substitutional Mn 2+ ions play a significant role for the low temperature ferromagnetism. Lattice defects such as V O and V Zn were not proven to be effective factors for the origin of ferromagnetism in the films. The low temperature ferromagnetism might be interpreted as p–d hybridization from indirect coupling of Mn ions (Mn–O–Mn).

Preparation and characterization of novel nanocomposite films formed from silk fibroin and nano-TiO2.

Science.gov (United States)

Feng, Xin-Xing; Zhang, Li-Li; Chen, Jian-Yong; Guo, Yu-Hai; Zhang, Hua-Peng; Jia, Chang-Ian

2007-01-30

This paper describes the synthesis and characterization of new regenerated silk fibroin (SF)/nano-TiO(2) composite films. The preparation method, based on the sol-gel technique using butyl titanate as oxide precursor, could avoid reagglomeration of the prepared nanoparticles. Samples were characterized mainly by X-ray diffraction (XRD), ultra-violet (UV) spectroscopy, atomic force microscopy (AFM), Fourier transform infrared (FT-IR) spectroscopy, and thermogravimetric analysis (TGA). The UV and AFM results indicated that TiO(2) nanoparticles could be well dispersed inside the SF film, and the size of TiO(2) was about 80nm. The XRD and FT-IR analysis implied that the formation of nano-TiO(2) particles may induce the conformational transition of silk fibroin to a typical Silk II structure partly with the increasing of crystallinity in the composite films. Compared to the pure SF films, the mechanical and thermal properties of composite films were improved, and the solubility in water was decreased due to the conformational transition of silk fibroin to Silk II structure.

Preparation of high magneto-optical performance and crystalline quality Ce{sub 1}Gd{sub 2}Fe{sub 5−x}Ga{sub x}O{sub 12} films on CLNGG substrate crystal

Energy Technology Data Exchange (ETDEWEB)

Fu, Qiu-ping; Zheng, Ze-yuan; Lin, Nan-xi; Liu, Xiao-feng; Hong, Can-huang; Hu, Xiao-lin, E-mail: linamethyst@fzu.edu.cn; Zhuang, Nai-feng; Chen, Jian-zhong, E-mail: j.z.chen@fzu.edu.cn

2016-11-01

Thin films of Ce{sub 1}Gd{sub 2}Fe{sub 5−x}Ga{sub x}O{sub 12} (Ce,Ga:GIG) were prepared on Gd{sub 3}Ga{sub 5}O{sub 12} (GGG) and Ca{sub 2.90}Li{sub 0.30}Nb{sub 1.93}Ga{sub 2.76}O{sub 12} (CLNGG) substrates by using radio frequency magnetron sputtering technique. The phase, grain orientation, surface morphology, transmittance, magnetism and magnetic circular dichroism (MCD) properties of films were analyzed. And the effects of lattice mismatch and non-magnetic Ga{sup 3+}-doping were discussed. The results show that the films with higher crystallized quality and lower stress can be obtained by growing on CLNGG than on GGG. Moreover, the coercive force, magnetization, magneto-optical effect intensity and orientation of film can be effectively regulated by adjusting Ga{sup 3+}-doped concentration. - Highlights: • With excellent magneto-optical performance, Ce,Ga:GIG film has a good application prospect. • Ce,Ga:GIG film with high quality were prepared on CLNGG by RF magnetron sputtering. • Crystalline quality and morphology of films are intently related to the substrate. • Ga{sup 3+} doping obviously affect on magnetism and magneto-optical property of Ce:GIG film.

A short literature survey on iron and cobalt ion doped TiO{sub 2} thin films and photocatalytic activity of these films against fungi

Energy Technology Data Exchange (ETDEWEB)

Tatl Latin-Small-Letter-Dotless-I dil, Ilknur [Department of Chemistry, Faculty of Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Bacaks Latin-Small-Letter-Dotless-I z, Emin [Department of Physics, Faculty of Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Buruk, Celal Kurtulus [Department of Microbiology, Faculty of Medicine, Karadeniz Technical University, 61080 Trabzon (Turkey); Breen, Chris [Materials and Engineering Research Institution, Sheffield Hallam University, Sheffield S1 1WB (United Kingdom); Soekmen, Muenevver, E-mail: msokmen@ktu.edu.tr [Department of Chemistry, Faculty of Science, Karadeniz Technical University, 61080 Trabzon (Turkey)

2012-03-15

Highlights: Black-Right-Pointing-Pointer Co or Fe doped TiO{sub 2} thin films were prepared by sol-gel method. Black-Right-Pointing-Pointer We obtained lower E{sub g} values for Fe-doped and Co-TiO{sub 2} thin films. Black-Right-Pointing-Pointer Doping greatly affected the size and shape of the TiO{sub 2} nanoparticles. Black-Right-Pointing-Pointer Photocatalytic killing effect of the doped TiO{sub 2} thin films on C. albicans and A. niger was significantly higher than undoped TiO{sub 2} thin film for short exposure periods. - Abstract: In this study, a short recent literature survey which concentrated on the usage of Fe{sup 3+} or Co{sup 2+} ion doped TiO{sub 2} thin films and suspensions were summarized. Additionally, a sol-gel method was used for preparation of the 2% Co or Fe doped TiO{sub 2} thin films. The surface of the prepared materials was characterised using scanning-electron microscopy (SEM) combined with energy dispersive X-ray (EDX) analysis and band gap of the films were calculated from the transmission measurements that were taken over the range of 190 and 1100 nm. The E{sub g} value was 3.40 eV for the pure TiO{sub 2}, 3.00 eV for the Fe-doped TiO{sub 2} film and 3.25 eV for Co-TiO{sub 2} thin film. Iron or cobalt doping at lower concentration produce more uniformed particles and doping greatly affected the size and shape of the TiO{sub 2} nanoparticles. Photocatalytic killing effect of the 2% Co doped TiO{sub 2} thin film on Candida albicans was significantly higher than Fe doped TiO{sub 2} thin film for short and long exposure periods. Doped thin films were more effective on Aspergillus niger for short exposure periods.

Josephson effectss in bicrystalline Bi2Sr2CaCu2O8+δ thin films

International Nuclear Information System (INIS)

Amrein, T.

1994-08-01

A pulsed laser deposition process is developed for preparing high quality thin films of Bi 2 Sr 2 CaCu 2 O x on different substrates. Both microstructural and electrical properties of the superconducting films are well characterized, e.g. by SEM, TEM and AFM. The high reproducability of the thin film quality facilitated a detailed study of Josephson effects in bicrystalline grain boundary junctions (GBJs). Thin films are deposited on commercially available (001) SrTiO 3 bicrystalls and patterned by standard photolithography using wet-etching or Ar + -ion milling. The width of the micobridges ranges from 2 to 111 μm. The critical current densities across grain boundaries of thin film bicrystals have been measured as a function of the tilt angle Θ. For Θ=0 to 45 , the ratio of the grain boundary critical current density to the bulk critical current density decreases exponentially with increasing tilt angle. Microstructure investigations show a rough grain boundary of the superconductor (roughness 100 nm-1 μm) which is not determined by the roughness of the substrate grain boundary (1-3 nm) but by the island-plus-layer growth of the twin domains. The electrical properties are well described by the resistively shunted junction (RSJ) model. The I c R n -product reaches values of 2.2 mV at 4.2 K and 60 μV at 77 K. An optimized design for dc SQUIDs (Θ=24 ) is developed relating to the results of single GBJs. The values of the transfer function (∂V/∂Φ) run up to 74 μV/Φ o . The equivalent flux noise which is measured in a flux-locked loop mode amounts 4.5 to 25 μPhi o Hz in the white noise region for Φ≥25-50 Hz and 13 to 150 μΦ o Hz at 1 Hz. In conclusion, microstructural as well as electrical properties of bicrystalline Bi 2 Sr 2 CaCu 2 O x and YBa 2 Cu 3 O y GBJs are more or less equal. (orig.)

Structure and optical band-gap energies of Ba0.5Sr0.5TiO3 thin films fabricated by RF magnetron plasma sputtering

International Nuclear Information System (INIS)

Xu, Zhimou; Suzuki, Masato; Yokoyama, Shin

2005-01-01

The structure and optical band-gap energies of Ba 0.5 Sr 0.5 TiO 3 (BST0.5) thin films prepared on SiO 2 /Si and fused quartz substrates by RF magnetron plasma sputtering were studied in terms of deposition temperature and film thickness. Highly (100)-oriented BST0.5 thin films were successfully sputtered on a Si substrate with an approximately 1.0-μm-thick SiO 2 layer at a deposition temperature of above 450degC. The optical transmittance of BST0.5 thin films weakly depended on the magnitude of X-ray diffraction (XRD) peak intensity. This is very helpful for monolithic integration of BST0.5 films for electrooptical functions directly onto a SiO 2 /Si substrate. The band-gap energies showed a strong dependence on the deposition temperature and film thickness. It was mainly related to the quantum size effect and the influence of the crystallinity of thin films, such as grain boundaries, grain size, oriented growth, and the existence of an amorphous phase. The band-gap energy values, which were much larger than those of single crystals, decreased with the increase in the deposition temperature and the thickness of BST0.5 thin films. The band-gap energy of 311-nm-thick amorphous BST0.5 thin film was about 4.45 eV and that of (100)-oriented BST0.5 thin film with a thickness of 447 nm was about 3.89 eV. It is believed that the dependence of the band-gap energies of the thin films on the crystallinity for various values of deposition temperature and film thickness means that there could be application in integrated optical devices. (author)

Photoelectrolytic hydrogen production using Bi{sub 2}MNbO{sub 7} (M = Al, Ga) semiconductor film electrodes prepared by dip-coating

Energy Technology Data Exchange (ETDEWEB)

Rosas-Barrera, K.L. [Grupo de Investigaciones en Minerales, Biohidrometalurgia y Ambiente - GIMBA, Universidad Industrial de Santander - UIS, Sede Guatiguara, Km. 2 via El Refugio, C.P. 681011, Piedecusta, Santander (Colombia); Pedraza-Avella, J.A. [Centro de Investigaciones en Catalisis - CICAT, Universidad Industrial de Santander - UIS, Sede Guatiguara, Km. 2 via El Refugio, C.P. 681011, Piedecuesta, Santander (Colombia); Ballen-Gaitan, B.P.; Cortes-Pena, J.; Pedraza-Rosas, J.E. [Grupo de Investigaciones en Minerales, Biohidrometalurgia y Ambiente - GIMBA, Universidad Industrial de Santander - UIS, Sede Guatiguara, Km. 2 via El Refugio, C.P. 681011, Piedecusta (Santander) (Colombia); Laverde-Catano, D.A., E-mail: dlaverde@uis.edu.co [Grupo de Investigaciones en Minerales, Biohidrometalurgia y Ambiente - GIMBA, Universidad Industrial de Santander - UIS, Sede Guatiguara, Km. 2 via El Refugio, C.P. 681011, Piedecusta, Santander (Colombia)

2011-10-25

The performance of Bi{sub 2}MNbO{sub 7} (M = Al, Ga) films on AISI/SAE 304 stainless steel was evaluated in the photoelectrochemical hydrogen production as a function of the annealing temperature of the films (400, 500 and 600 deg. C) and the composition of the electrolyte solution (containing KOH, KCN and KCl). The films were prepared by sol-gel dip-coating on AISI/SAE 304 stainless steel followed by a thermal annealing. The photoelectrochemical evaluation (UV-Vis, 2.5 V) was carried out in a conventional two-compartment electrochemical cell by using the prepared films as photoanode and a silver plate as cathode. During the process, circulating current was recorded and hydrogen production and cyanide degradation were measured. In both cases, it was found that the higher activity was obtained with the films annealed at 500 deg. C and using an electrolyte solution 0.3 M of KOH and 120 ppm of CN{sup -}. Further works on the subject should involve a cathode evaluation to avoid the electrode polarization in presence of KCl and an experimental design to optimize the evaluated variables.

Influence of Sn ion doping on the photocatalytic performance of V2O5 nanorods prepared by hydrothermal method

Science.gov (United States)

Rajeshwari, S.; Santhosh Kumar, J.; Rajendrakumar, R. T.; Ponpandian, N.; Thangadurai, P.

2018-02-01

Pure and different concentrations of Sn4+ doped V2O5 (Sn:V2O5) nanorods were synthesized by hydrothermal method. The Sn:V2O5 nanorods obtained were orthorhombic in structure. No secondary phase was observed up to 10% of Sn doping, but beyond that, there evolved a secondary phase of SnO2. Microstructural analysis revealed the morphology of V2O5 as nanorods and platelets like structure. Presence of V, O and Sn elements in the samples was confirmed by energy dispersive spectroscopy. The V2O5 nanorods have shown a strong absorption in the visible region and the band gap energy was obtained to be varying from 2.21 to 2.26 eV as a function of Sn ion doping. Photocatalytic studies on methylene blue (MB) under visible light irradiation showed that the 3% Sn:V2O5 had effectively degraded MB up to a maximum degradation of 96% and further increase in Sn content had decreased the photodegradation due to higher recombination rate of photogenerated electrons. The mechanism of photodegradation was completely understood and the OH· radicals have played a dominant role in the photodegradation of the organic dyes.

The effects of heat treatment on optical, structural, electrochromic and bonding properties of Nb{sub 2}O{sub 5} thin films

Energy Technology Data Exchange (ETDEWEB)

Coşkun, Özlem Duyar, E-mail: duyar@hacettepe.edu.tr [Hacettepe University, Department of Physics Engineering, Thin Film Preparation and Characterization Laboratory, Ankara (Turkey); Demirel, Selen, E-mail: nymph24@gmail.com [Hacettepe University, Department of Physics Engineering, Thin Film Preparation and Characterization Laboratory, Ankara (Turkey); Hacettepe University, Nanotechnology and Nanomedicine Department, Ankara (Turkey); Atak, Gamze, E-mail: gbaser@hacettepe.edu.tr [Hacettepe University, Department of Physics Engineering, Thin Film Preparation and Characterization Laboratory, Ankara (Turkey)

2015-11-05

Nb{sub 2}O{sub 5} thin films were deposited onto heated glass substrates by RF magnetron sputtering using a Nb{sub 2}O{sub 5} target. The films were annealed in air at temperatures between 400 and 700 °C for 6 h. Effects of the crystalline structure on optical, structural, electrochromic and bonding properties of the Nb{sub 2}O{sub 5} thin films were investigated by X-ray diffraction, atomic force microscopy, X-ray photoelectron spectroscopy, optical spectrophotometry and electrochemical measurements. The film refractive index varied between 2.09 and 2.22 at the wavelength of 550 nm depending on the annealing temperature. The decrease of the optical band gap revealed for the films with increasing annealing temperature is attributed to oxygen-ion vacancies in the film structure. The orthorhombic structure of Nb{sub 2}O{sub 5} films resulted in good electrochromic properties with high colouration efficiencies of 19.56 cm{sup 2}/C and 53.24 cm{sup 2}/C at 550 nm and 1000 nm, respectively. The optical, structural and electrochromic properties of the different crystalline polymorphic forms of the Nb{sub 2}O{sub 5} films make them attractive for optical applications. - Highlights: • Stoichiometric Nb{sub 2}O{sub 5} films prepared using RF magnetron sputtering technique. • The different crystalline forms of Nb{sub 2}O{sub 5} thin films obtained by annealing. • The optical, structural and electrochromic properties of the films were investigated. • The optical band gap decreased with increasing annealing temperature. • The orthorhombic T-Nb{sub 2}O{sub 5} films exhibited a higher colouration efficiency.

Caracterização textural e estrutural de V2O5/TiO2 obtidos via sol-gel: comparação entre secagem convencional e supercrítica Textural and structural characterization of V2O5/TiO2 catalysts obtained by the sol-gel method: comparison between conventional and supercritical drying

Directory of Open Access Journals (Sweden)

Cristiane B. Rodella

2002-05-01

Full Text Available This work describes a modified sol-gel method for the preparation of V2O5/TiO2 catalysts. The samples have been characterized by N2 adsorption at 77K, x-ray diffractometry (XRD and Fourier Transform Infrared (FT-IR. The surface area increases with the vanadia loading from 24 m² g-1, for pure TiO2, to 87 m² g-1 for 9wt.% of V2O5. The rutile form is predominant for pure TiO2 but became enriched with anatase phase when vanadia loading is increased. No crystalline V2O5 phase was observed in the catalysts diffractograms. Two species of surface vanadium observed by FT-IR spectroscopy a monomeric vanadyl and polymeric vanadates, the vanadyl/vanadate ratio remains practically constant.

Corrosion of thin, magnetron sputtered Nb_2O_5 films

International Nuclear Information System (INIS)

Pillis, Marina Fuser; Geribola, Guilherme Altomari; Scheidt, Guilherme; Gonçalves de Araújo, Edval; Lopes de Oliveira, Mara Cristina; Antunes, Renato Altobelli

2016-01-01

Highlights: • Niobium oxide based films were obtained by DC magnetron sputtering. • Different deposition times were tested. • The best corrosion resistance was obtained for the Nb_2O_5 film produced at 15′. • Film porosity determines the corrosion resistance. - Abstract: Niobium oxide based thin films were deposited on AISI 316 stainless steel substrates using reactive DC magnetron sputtering. Structure, composition and corrosion resistance of the niobium oxide films were studied. The corrosion behavior of the specimens was evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The concentration of niobium and oxygen in the films was obtained by Rutherford backscattering spectroscopy (RBS). The film structure was analyzed by X-ray diffractometry. The corrosion resistance of the substrate was improved by the Nb_2O_5 layers. The best protective performance was achieved for the deposition time of 15 min.

Structural and optical properties of sol-gel deposited proton conducting Ta{sub 2}O{sub 5} films

Energy Technology Data Exchange (ETDEWEB)

Ozer, N.; Lampert, C.M.

1995-08-01

Proton conducting tantalum oxide films were deposited by spin coating using a sol-gel process. The coating solutions were prepared using Ta(OC{sub 2}H{sub 5}){sub 5} as a precursor. X-ray diffraction studies determined that the sol-gel films, heat treated at temperatures below 400 C, were amorphous. Films heat treated at higher temperatures were crystalline Ta{sub 2}O{sub 5}. The solar transmission values (T{sub s}) of tantala films on glass generally range from 0.8--0.9 depending on thickness. The refractive index and the extinction coefficient were evaluated from transmittance characteristics in the UV-VIS-NIR regions. The refractive index values calculated at 550 nm increased from 1.78 to 1.97 with increasing heat treatment from 150 to 450 C. The films heat treated at different temperatures showed low absorption with extinction coefficients of less than k=1x10{sup -3} in the visible range. Spectrophotometric and impedance spectroscopic investigations performed on Ta{sub 2}O{sub 5} films revealed that these films have protonic conductivity of 3.2x10{sup -6} S/cm. The films are suitable for proton conducting layers in electrochromic (EC) devices.

Preparation and switching kinetics of Pb(Zr, Ti)O3 thin films deposited by reactive sputtering

International Nuclear Information System (INIS)

Hase, Takashi; Shiosaki, Tadashi

1991-01-01

Ferroelectric Pb(Zr, Ti)O 3 [PZT] thin films have been prepared on Pt/Ti/SiO 2 /Si and Pt/SiO 2 /Si substrates using the reactive sputtering method with a metal composite target. The (111)-oriented PZT (80/20) thin films with a perovskite structure have been obtained at a substrate temperature of 595degC on highly (111)-oriented Pt films formed on SiO 2 /Si substrates. When an 8 V pulse sequence was applied to a 265 nm-thick film with an electrode area of 50 x 50 μm 2 , the switching time and the switched charge density measured were 20 ns and 10 μC/cm 2 , respectively. The switching time was strongly dependent on the electrode area. (author)

Growth and characterisation of potentiostatically electrodeposited Cu2O and Cu thin films

International Nuclear Information System (INIS)

Wijesundera, R.P.; Hidaka, M.; Koga, K.; Sakai, M.; Siripala, W.

2006-01-01

Cuprous oxide and copper thin films were potentiostatically electrodeposited in an acetate bath. Voltammetric curves were used to investigate the growth parameters; deposition potential, pH and temperature of the bath. Deposition potential dependency on the structural, morphological, optical and electronic properties of the films were investigated by the X-ray diffraction measurements, scanning electron micrographs, absorption measurements and dark and light current-voltage characterisations. It was observed that single phase polycrystalline Cu 2 O can be deposited from 0 to - 300 mV Vs saturated calomel electrode (SCE) and co-deposition of Cu and Cu 2 O starts at - 400 mV Vs SCE. Further increase in deposition potential from - 700 mV Vs SCE produces single phase Cu thin films. Single phase polycrystalline Cu 2 O thin films with cubic grains of 1-2 μm can be possible within the very narrow potential domain around - 200 mV Vs SCE. Enhanced photoresponse in a photoelectrochemical cell is produced by the Cu 2 O thin film prepared at - 400 mV Vs SCE, where Cu is co-deposited with Cu 2 O with random distribution of Cu spheres on the Cu 2 O surface. This study reveals that a single deposition bath can be used to deposit both Cu and Cu 2 O separately and an admixture of Cu-Cu 2 O by controlling the deposition parameters

Electrochemical sensing property of Mn doped V2O5 nanoparticles

International Nuclear Information System (INIS)

Suresh, R.; Giribabu, K.; Manigandan, R.; Narayanan, V.; Vijayalakshmi, L.; Stephen, A.

2012-01-01

In this study, pure V 2 O 5 and Mn doped V 2 O 5 nanoparticles were synthesized by thermal decomposition method. The FT-IR spectrum of Mn doped V 2 O 5 shows the bands at 822 and 1027 cm -1 which essentiaIIy of crystalline V 2 O 5 . Further, the bands observed in Mn doped V 2 O 5 are all shifted to lower wave number than the V 2 O 5 . The optical property of the nanocomposite was studied using UV-Visible absorption spectroscopy. The XRD data also revealed that the Mn doped V 2 O 5 obtained had an orthorhombic structure. The diffraction peaks in Mn doped V 2 O 5 nanoparticles are similar to that of V 2 O 5 . There was no indication of any other impurities in the sample. However, all the peaks of V 2 O 5 are slightly shifted to tower 2θ values. The FE-SEM image of V 2 O 5 shows that the particles adopt ellipse-like particles with different sizes due to aggregation. The synthesized nanoparticles were used to modify glassy carbon electrode (GCE) and the modified electrode was used to detect uric acid (UA) by voltammetric techniques. The effects of Mn on the optical, morphological and electrochemical detecting property of V 2 O 5 have also been studied. (author)

Effects of Preparation Conditions on the CuInS2 Films Prepared by One-Step Electrodeposition Method

Directory of Open Access Journals (Sweden)

Rongfeng Guan

2015-01-01

Full Text Available CuInS2 thin films were prepared onto indium tin oxide (ITO substrates by sulfurization of electrodeposited CuxInySz precursor films under S atmosphere. The influences of deposition potential, Cu2+/In3+ ratio, sulfurization temperature, and sulfur content on the CuInS2 thin films were investigated. Phases and structures were characterized by powder X-ray diffraction and Raman spectroscopy; surface morphology was characterized by Scanning Electron Microscopy; optical and electrical properties were characterized by UV-Vis absorption and Mott-Schottky curves, respectively. As a result, the optimal well-crystallized CuInS2 films preparation parameters were determined to be deposition potential of −0.8 V, Cu2+/In3+ ratio of 1.4, sulfur content of 1 g, and the sulfurization temperature of 550°C for 1 h; CuInS2 thin films prepared by one-step electrodeposition present the p-type semiconductor, with thickness about 4-5 μm and their optical band gaps in the range of 1.53~1.55 eV.

Flexible Fe2O3 and V2O5 nanofibers as binder-free electrodes for high-performance all-solid-state asymmetric supercapacitors.

Science.gov (United States)

Jiang, He; Niu, Hao; Yang, Xue; Sun, Zhiqin; Li, Fuzhi; Wang, Qian; Qu, Fengyu

2018-04-16

Flexible highly porous Fe2O3 and V2O5 nanofibers are synthesized by a facile electrospinning method followed by calcination treatment and directly used as binder-free electrodes for high-performance supercapacitors. These Fe2O3 and V2O5 nanofibers interconnect with each other and construct three-dimensional hierarchical porous films with high specific surface area. Benefiting from the unique structural features, the intriguing binder-free Fe2O3 and V2O5 porous nanofiber electrodes possess high specific capacitance of 255 F g-1 and 256 F g-1 at 2 mV s-1 in 1 M Na2SO4 electrolyte, respectively. An all-solid-state asymmetric supercapacitor is fabricated using Fe2O3 and V2O5 nanofibers as negative and positive electrodes, respectively, and the all-solid-state asymmetric supercapacitor can be operated up to 1.8 V attributed to the wide and opposite potential window of both electrodes. The assembled all-solid-state asymmetric supercapacitor achieves a high energy density up to 32.2 Wh kg-1 at an average power density of 128.7 W kg-1 as well as excellent cycling stability and power capability. The effective and facile synthesis method and superior electrochemical performance provided in this work make electrospun Fe2O3 and V2O5 nanofibers promising electrode materials for high performance asymmetric supercapacitors. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation of YBa2Cu3O7-δ epitaxial thin films by pulsed ion-beam evaporation

International Nuclear Information System (INIS)

Sorasit, S.; Yoshida, G.; Suzuki, T.; Suematsu, H.; Jiang, W.; Yatsui, K.

2001-01-01

Thin films of YBa 2 Cu 3 O 7-δ (Y-123) grown epitaxially have been successfully deposited by ion-beam evaporation (IBE). The c-axis oriented YBa 2 Cu 3 O 7-δ thin films were successfully deposited on MgO and SrTiO 3 substrates. The Y-123 thin films which were prepared on the SrTiO 3 substrates were confirmed to be epitaxially grown, by X-ray diffraction analysis. The instantaneous deposition rate of the Y-123 thin films was estimated as high as 4 mm/s. (author)

Fabrication and characterization of CuAlO2 transparent thin films prepared by spray technique

International Nuclear Information System (INIS)

Bouzidi, C.; Bouzouita, H.; Timoumi, A.; Rezig, B.

2005-01-01

CuAlO 2 thin films have been grown on glass substrates using spray technique; a low-cost method of thin films depositing. The deposition was carried out in a 450-525 deg. C range of substrate temperature. The solution and gas flow rates were kept constant at 5 cm 3 min -1 and 6.10 -3 m 3 min -1 , respectively. Compressed air was used as a carrier gas. The structural, morphological and optical properties of these thin films have been studied. These properties are strongly related to the substrate temperature and to the [Cu]/[Al] molar ratio r. X-ray diffraction analysis confirmed the initial amorphous nature of as-deposited films and phase transition into crystalline CuAlO 2 with the preferential orientation (1 0 1) upon annealing at 570 deg. C. The optical transmission of 80% has been achieved in the visible spectrum. CuAlO 2 band gap energy in the range of 3.34-3.87 eV has been found by optical measurement depending on fabrication parameters

Studies on annealed ZnO:V thin films deposited by nebulised spray pyrolysis method

Science.gov (United States)

Malini, D. Rachel

2018-04-01

Structural, optical and photoluminescence properties of annealed ZnO:V thin films deposited by nebulized spray pyrolysis technique by varying vanadium concentration are studied. Thickness of thin films varies from 1.52µm to 7.78µm. V2O5, VO2 and ZnO peaks are observed in XRD patterns deposited with high vanadium concentration and the intensity of peaks corresponding to ZnO decreases in those samples. Morphological properties were studied by analysing SEM images and annealed thin films deposited at ZnO:V = 50:50 possess dumb bell shape grains. Emission peaks corresponding to both Augur transition and deep level transition are observed in the PL spectra of the samples.

Visible light active TiO2 films prepared by electron beam deposition of noble metals

International Nuclear Information System (INIS)

Hou Xinggang; Ma Jun; Liu Andong; Li Dejun; Huang Meidong; Deng Xiangyun

2010-01-01

TiO 2 films prepared by sol-gel method were modified by electron beam deposition of noble metals (Pt, Pd, and Ag). Effects of noble metals on the chemical and surface characteristics of the films were studied using XPS, TEM and UV-Vis spectroscopy techniques. Photocatalytic activity of modified TiO 2 films was evaluated by studying the degradation of methyl orange dye solution under visible light UV irradiation. The result of TEM reveals that most of the surface area of TiO 2 is covered by tiny particles of noble metals with diameter less than 1 nm. Broad red shift of UV-Visible absorption band of modified photocatalysts was observed. The catalytic degradation of methyl orange in aqueous solutions under visible light illumination demonstrates a significant enhancement of photocatalytic activity of these films compared with the un-loaded films. The photocatalytic efficiency of modified TiO 2 films by this method is affected by the concentration of impregnating solution.

High-performance supercapacitors based on intertwined CNT/V{sub 2}O{sub 5} nanowire nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Chen, Zheng; Shen, Meiqing [School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 (China); Augustyn, Veronica; Dunn, Bruce [Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095 (United States); Wen, Jing; Zhang, Yuewei [Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095 (United States); School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 (China); Lu, Yunfeng [Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095 (United States)

2011-02-08

High-performance asymmetric super-capacitors containing thick-film electrodes (over 100 {mu}m thick) made of CNT/V{sub 2}O{sub 5} nanowire composite are designed. The excellent conductivity, high specific capacitance, and a large voltage window of the CNT/V{sub 2}O{sub 5} nanocomposite enable the fabrication of devices with high energy and high power densities. Moreover, the resulting devices exhibit excellent cycling stability. This supercapacitor approach may be attractive for a wide range of device applications. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Preparation of sensitive and recyclable porous Ag/TiO{sub 2} composite films for SERS detection

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhengyi; Yu, Jiajie; Yang, Jingying; Lv, Xiang; Wang, Tianhe, E-mail: thwang56@126.com

2015-12-30

Graphical abstract: - Highlights: • A new but simple method of fabricating robust TiO{sub 2} films on glass. • AgNPs were deposited on the surface of TiO{sub 2} films with the assistance of UV irradiation. • Substrates with high SERS sensitivity and excellent recyclability. - Abstract: Porous Ag/TiO{sub 2} composite films were prepared by spin coating of titania on normal glass slides and subsequent photochemical deposition of silver nanoparticles (AgNPs). The films were characterized by XRD and FESEM to reveal micro structural and morphological differences between films obtained under varied conditions. The SERS properties of these films were investigated using aqueous crystal violet (CV) as probe molecules. The results indicate that the content of polyethylene glycol (PEG) and photo-reduction time had significant influences on both the microstructure and SERS performance of Ag/TiO{sub 2} films. The highest SERS sensitivity that allowed as low as 10{sup −10} M aqueous CV to be detected, was achieved with the PEG/(C{sub 4}H{sub 9}O){sub 4}Ti molar ratio being 0.08% and with 30 min of UV irradiation. With this film a linear relationship was established through experiment between SERS intensity and CV concentration from 10{sup −10} to 10{sup −5} M, which could be used as a calibration curve for CV concentration measurement. In addition, the film could be reused as a SERS substrate for up to four times without significantly losing SERS sensitivity if a simple regeneration was followed. It is visualized that the Ag/TiO{sub 2} film on glass has potentials for being developed into a practical SERS substrate with high sensitivity and good reusability.

Preparation and characterization of electrodeposited CuInSe{sub 2} thin films; Preparation et caracterisation des couches minces de CuInSe{sub 2} electrodeposees

Energy Technology Data Exchange (ETDEWEB)

Fahoume, M.; Chraibi, F.; Ennaoui, A. [Universite Mohammed 5, Rabat (Morocco). Faculte des Sciences; Fahoume, M.; Aggour, M. [Universite Ibn Tofail, Faculte des Sciences, Kenitra (Morocco)

1998-01-01

CuInSe{sub 2} is one of the most promising materials for use in photoelectrochemical as well in photovoltaic solar cells because of its excellent photoactive properties such as high optical absorption coefficient (10`4-10`5 cm`-`1) and good stability. It has been prepared from an aqueous solution containing CuCl{sub 2}, InCl{sub 3}, H{sub 2}SeO{sub 3} complexed by citrate (Na{sub 3}C{sub 6}H{sub 5}O{sub 7}). The kinetics of electrodeposition has been studied by using the rotating disk electrode method (RDE). X-ray diffraction showed the formation of CuInSe{sub 2} films, of chalcopyrite structure, at potentials ranged between -0.95 V and - 1.12 V (vs. SSE). The composition of the deposited films has been studied by energy dispersive analysis of X-rays (EDAX) and Rutherford backscattering spectroscopy (RBS). From the results, it has been found that stoichiometric chalcopyrite CuInSe{sub 2} has been obtained by controlling both composition, deposition potential, solution temperature and pH. (authors) 16 refs.

Origin of room temperature ferromagnetism in SnO{sub 2} films

Energy Technology Data Exchange (ETDEWEB)

Li, Jing [School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China); National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Bai, Guohua; Jiang, Yinzhu [School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); Du, Youwei [National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Wu, Chen, E-mail: chen_wu@zju.edu.cn [School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); Yan, Mi, E-mail: mse_yanmi@zju.edu.cn [School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China)

2017-03-15

SnO{sub 2} films exhibiting room temperature ferromagnetism (RTFM) have been prepared on Si (001) by pulsed laser deposition. The saturation magnetization (M{sub s}) of the films experiences a decreasing trend followed by increasing with the growth temperature increased from RT to 400 ℃. The growth temperature affects both the concentration and the location of the oxygen vacancies as the origin of the RTFM. With lower growth temperatures (<300 ℃), more oxygen vacancies exist in the inner film for the samples with less crystallinity, resulting in enhanced magnetism. Higher deposition temperature leads to less oxygen vacancies in the inner film but more oxygen defects at the film surface, which is also beneficial to achieve greater magnetism. Various oxygen pressures during growth and post-annealing have also been used to confirm the role of oxygen vacancies. The study demonstrates that the surface oxygen defects and the positively charged monovalent O vacancies (V{sub O}{sup +}) in the inner film are the origin of the magnetism in SnO{sub 2} films. - Highlights: • SnO{sub 2} films exhibiting room temperature ferromagnetism (RTFM) have been prepared on Si (001) by pulsed laser deposition. • Growth temperature, oxygen pressure and annealing affect the growth of SnO{sub 2} films. • Both the concentration and location of the oxygen vacancies play critical roles in the magnetization.

Analysis of deuterium in V-Fe5at.% film by atom probe tomography (APT)

KAUST Repository

Gemma, Ryota; Al-Kassab, Talaat; Kirchheim, Reiner; Pundt, Astrid A.

2011-01-01

V-Fe5at.% 2 and 10-nm thick single layered films were prepared by ion beam sputtering on W substrate. They were loaded with D from gas phase at 0.2 Pa and at 1 Pa, respectively. Both lateral and depth D distribution of these films was investigated

Imaging of alpha(v)beta(3) expression by a bifunctional chimeric RGD peptide not cross-reacting with alpha(v)beta(5).