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Sample records for chemical spray pyrolysis

  1. Surface morphology engineering of metal-oxide films by chemical spray pyrolysis

    International Nuclear Information System (INIS)

    The Chemical Spray Pyrolysis technique and a combination of sol-gel and spray pyrolysis techniques have been used in order to monitor the morphology of metal-oxide-based thin films to be used as functional materials. We can obtain surfaces from specular to rough-porous according to the physico-chemical conditions of the precursor/spraying solution. We have produced coatings of ZnO-based and NiOx-based coatings from alcoholic and aqueous solutions. A single glass, ITO-precoated glass or alumina was used as the substrate. Porous materials of WO3, WO3-SnO2 and SnO2 have been produced by spraying either inorganic or metal alkoxide gels over a hot substrate. The morphologies of coatings were evaluated by either SEM or optical measurements. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Surface morphology engineering of metal-oxide films by chemical spray pyrolysis

    International Nuclear Information System (INIS)

    Chemical spray pyrolysis technique and a combination of sol-gel and spray pyrolysis techniques have been used in order to monitor the morphology of metal-oxide-based thin films to be used as functional materials. We can get from specular to rough-porous surfaces according to the physical-chemical conditions of the precursor / spraying solution. We have produced coatings of ZnO-based and NiOx-based coatings from alcoholic and water solution. A single glass, ITO-precoated glass or alumina was used as the substrate. Porous materials of WO3, CuWO4-x and SnO2 have been produced spraying either inorganic or metal alkoxide gels over a hot substrate. Morphology of coatings were evaluated by either SEM or optical measurements. (author)

  3. Fabrication of ZnO nanorod using spray-pyrolysis and chemical bath deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Ramadhani, Muhammad F., E-mail: brian@tf.itb.ac.id; Pasaribu, Maruli A. H., E-mail: brian@tf.itb.ac.id; Yuliarto, Brian, E-mail: brian@tf.itb.ac.id; Nugraha, E-mail: brian@tf.itb.ac.id [Advanced Functional Materials Laboratory, Engineering Physics Department Faculty of Industrial Technology, Institut Teknologi Bandung (Indonesia)

    2014-02-24

    ZnO thin films with nanorod structure were deposited using Ultrasonic Spray Pyrolysis method for seed growth, and Chemical Bath Deposition (CBD) for nanorod growth. High purity Zn-hydrate and Urea are used to control Ph were dissolved in ethanol and aqua bidest in Ultrasonic Spray Pyrolysis process. Glass substrate was placed above the heater plate of reaction chamber, and subsequently sprayed with the range duration of 5, 10 and 20 minutes at the temperatures of 3500 C. As for the Chemical Bath Deposition, the glass substrate with ZnO seed on the surface was immerse to Zn-hydrate, HMTA (Hexa Methylene Tetra Amine) and deionized water solution for duration of 3, 5 and 7 hour and temperatures of 600 C, washed in distilled water, dried, and annealed at 3500 C for an hour. The characterization of samples was carried out to reveal the surface morphology using Scanning Electron Microscopy (SEM). From the data, the combination of 5 minutes of Ultrasonic Spray Pyrolysis process and 3 hour of CBD has showed the best structure of nanorod. Meanwhile the longer Spraying process and CBD yield the bigger nanorod structure that have been made, and it makes the films more dense which make the nanorod collide each other and as a result produce unsymetric nanorod structure.

  4. Fabrication of ZnO nanorod using spray-pyrolysis and chemical bath deposition method

    International Nuclear Information System (INIS)

    ZnO thin films with nanorod structure were deposited using Ultrasonic Spray Pyrolysis method for seed growth, and Chemical Bath Deposition (CBD) for nanorod growth. High purity Zn-hydrate and Urea are used to control Ph were dissolved in ethanol and aqua bidest in Ultrasonic Spray Pyrolysis process. Glass substrate was placed above the heater plate of reaction chamber, and subsequently sprayed with the range duration of 5, 10 and 20 minutes at the temperatures of 3500 C. As for the Chemical Bath Deposition, the glass substrate with ZnO seed on the surface was immerse to Zn-hydrate, HMTA (Hexa Methylene Tetra Amine) and deionized water solution for duration of 3, 5 and 7 hour and temperatures of 600 C, washed in distilled water, dried, and annealed at 3500 C for an hour. The characterization of samples was carried out to reveal the surface morphology using Scanning Electron Microscopy (SEM). From the data, the combination of 5 minutes of Ultrasonic Spray Pyrolysis process and 3 hour of CBD has showed the best structure of nanorod. Meanwhile the longer Spraying process and CBD yield the bigger nanorod structure that have been made, and it makes the films more dense which make the nanorod collide each other and as a result produce unsymetric nanorod structure

  5. Nonlinear optical characterization of ZnS thin film synthesized by chemical spray pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    G, Sreeja V; Anila, E. I., E-mail: anilaei@gmail.com; R, Reshmi, E-mail: anilaei@gmail.com; John, Manu Punnan, E-mail: anilaei@gmail.com [Optolectronic and Nanomaterials Research Laboratory, Department of Physics, Union Christian College, Aluva-683 102, Kerala (India); V, Sabitha P; Radhakrishnan, P. [International School of Photonics, CUSAT, Cochin-22 (India)

    2014-10-15

    ZnS thin film was prepared by Chemical Spray Pyrolysis (CSP) method. The sample was characterized by X-ray diffraction method and Z scan technique. XRD pattern showed that ZnS thin film has hexagonal structure with an average size of about 5.6nm. The nonlinear optical properties of ZnS thin film was studied by open aperture Z-Scan technique using Q-switched Nd-Yag Laser at 532nm. The Z-scan plot showed that the investigated ZnS thin film has saturable absorption behavior. The nonlinear absorption coefficient and saturation intensity were also estimated.

  6. Studies on transparent spinel magnesium indium oxide thin films prepared by chemical spray pyrolysis

    International Nuclear Information System (INIS)

    Ternary semiconducting oxide compound magnesium indium oxide films (MgIn2O4), manifesting high transparency were prepared by metal organic chemical spray pyrolysis technique. Precursors prepared for various cationic ratios of Mg/In = 0.35, 0.40, 0.45 and 0.50 were thermally sprayed onto quartz substrates, decomposed at 450 deg. C and the spinel phase evolution was studied. X-ray diffraction, Rutherford backscattering and X-ray photoelectron spectroscopy studies have been conducted to confirm the formation of single-phase MgIn2O4 films with Mg/In ratio 0.50. From optical transmission studies, the observed optical band gaps varied from 3.18 to 3.86 eV (0.35 -5 S cm-1) and the Hall coefficient showed n-type electrical conduction and high carrier concentration (0.16 x 1020-0.89 x 17 cm-3)

  7. Hydrogen-free spray pyrolysis chemical vapor deposition method for the carbon nanotube growth: Parametric studies

    International Nuclear Information System (INIS)

    Spray pyrolysis chemical vapor deposition (CVD) in the absence of hydrogen at low carrier gas flow rates has been used for the growth of carbon nanotubes (CNTs). A parametric study of the carbon nanotube growth has been conducted by optimizing various parameters such as temperature, injection speed, precursor volume, and catalyst concentration. Experimental observations and characterizations reveal that the growth rate, size and quality of the carbon nanotubes are significantly dependent on the reaction parameters. Scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy techniques were employed to characterize the morphology, structure and crystallinity of the carbon nanotubes. The synthesis process can be applied to both semiconducting silicon wafer and conducting substrates such as carbon microfibers and stainless steel plates. This approach promises great potential in building various nanodevices with different electron conducting requirements. In addition, the absence of hydrogen as a carrier gas and the relatively low synthesis temperature (typically 750 deg. C) qualify the spray pyrolysis CVD method as a safe and easy way to scale up the CNT growth, which is applicable in industrial production.

  8. Low-cost plasmonic solar cells prepared by chemical spray pyrolysis

    Directory of Open Access Journals (Sweden)

    Erki Kärber

    2014-12-01

    Full Text Available Solar cells consisting of an extremely thin In2S3/CuInS2 buffer/absorber layer uniformly covering planar ZnO were prepared entirely by chemical spray pyrolysis. Au nanoparticles (Au-NPs were formed via thermal decomposition of a gold(III chloride trihydrate (HAuCl4·3H2O precursor by spraying 2 mmol/L of the aqueous precursor solution onto a substrate held at 260 °C. Current–voltage scans and external quantum efficiency spectra were used to evaluate the solar cell performance. This work investigates the effect of the location of the Au-NP layer deposition (front side vs rear side in the solar cell and the effect of varying the volume (2.5–10 mL of the sprayed Au precursor solution. A 63% increase (from 4.6 to 7.5 mA/cm2 of the short-circuit current density was observed when 2.5 mL of the precursor solution was deposited onto the rear side of the solar cell.

  9. Effect of indium doping on zinc oxide films prepared by chemical spray pyrolysis technique

    Indian Academy of Sciences (India)

    Girjesh Singh; S B Shrivastava; Deepti Jain; Swati Pandya; T Shripathi; V Ganesan

    2010-10-01

    We report the conducting and transparent In doped ZnO films fabricated by a homemade chemical spray pyrolysis system (CSPT). The effect of In concentration on the structural, morphological, electrical and optical properties have been studied. These films are found to show (0 0 2) preferential growth at low indium concentrations. An increase in In concentration causes a decrease in crystalline quality of films as confirmed by X-ray diffraction technique which leads to the introduction of defects in ZnO. Indium doping also significantly increased the electron concentrations, making the films heavily type. However, the crystallinity and surface roughness of the films decreases with increase in indium doping content likely as a result of the formation of smaller grain size, which is clearly displayed in AFM images. Typical optical transmittance values in the order of (80%) were obtained for all films. The lowest resistivity value of 0.045 -m was obtained for film with 5% indium doping.

  10. Growth and characterization of the ZnO/ZnS bilayer obtained by chemical spray pyrolysis

    International Nuclear Information System (INIS)

    ZnO/ZnS bilayer antireflection coatings have been prepared by spray pyrolysis using aqueous solutions of zinc acetate and thiourea or zinc chloride and thiourea. The structure, surface morphology, chemical composition and optical transmittance of the bilayer have been examined as a function of the composition of the initial solution. X-ray photoelectron spectroscopy analysis and Ar ion-beam sputter etching was carried out to obtain a depth profile of bilayer. Neither carbon nor other by-products, which could alter the optical transmittance of the bilayer were found in either the interface or bulk. The differences between the bilayers arise from the annealing of the ZnS underlayer, as well as the precursor used to prepare it.

  11. Preparation and chemical characterization of neodymium-doped molybdenum oxide films grown using spray pyrolysis

    International Nuclear Information System (INIS)

    We studied the crystalline, morphology, and surface composition of Nd-doped molybdenum oxide films grown on glass slides through spray pyrolysis. After fabrication, the films were subjected to thermal treatment in oxygen for periods ranging from 2 to 20 hours. The films were structurally characterized though X-ray diffraction (XRD), their bulk chemical composition was determined using Energy-Dispersive X-ray analysis (EDX), and their surface composition was determined using X-ray Photoelectron Spectroscopy (XP S). The XRD results show that the films obtained from different dissolution volumes and at substrate temperature of 300 grades C exhibit the characteristics of the oxygen-deficient molybdenum trioxide Mo9O26 phase. The films subjected to different thermal treatments exhibit a mixture of Mo9O26 and Mo17O47 phases. EDX study shows the energy belonging to the L line of Nd. Finally, films doped with Nd and subjected to a thermal treatment of 20 h were analyzed through XP S, showing the binding energies at the crystalline lattice correspond to Nd2 (MoO4)3 and Nd2Mo2O7. (Author)

  12. Characterisation of samarium and nitrogen co-doped TiO2 films prepared by chemical spray pyrolysis

    International Nuclear Information System (INIS)

    Highlights: ► The TiO2:N:Sm thin films deposited by chemical spray pyrolysis have anatase structure. ► According to XPS, N is incorporated into the TiO2 matrix. ► N-doping increases and Sm-doping reduces the crystallite size of the TiO2:N:Sm films. ► Incorporation of N strongly suppresses the Sm3+ PL emission. - Abstract: The sol–gel chemical spray pyrolysis method was used to deposit samarium and nitrogen co-doped TiO2 films onto a quartz substrate at a growth temperature of 450 °C using pulsed spray solution feed, followed by annealing at 500 °C for 2 h in air. The obtained films exhibited anatase structure independent of the doping level. According to XRD analysis, the mean crystallite size of the undoped TiO2, TiO2:N(25) and TiO2:N(5):Sm(5) films was 32, 38 and 20 nm, respectively. According to AFM, the undoped TiO2 film consisted of agglomerates with a size of 30–200 nm. N-doping (25 at%) transformed the agglomerates into individually distinctive grains with a size of ca. 30 nm, while Sm doping (5 at%) caused a significant decrease in the average diameter of the agglomerates to ca. 100 nm. The RMS roughness of the undoped TiO2 film was 1.7 nm; doping resulted in the formation of smoother films with RMS roughness of 0.9–1.4 nm. XPS data indicated that the Sm and N dopants were incorporated into the TiO2 crystal lattice and/or adsorbed on the surface of the film. An increasing nitrogen concentration in the spray solution correlates to a systematic suppressing of the photoluminescence intensity of Sm3+.

  13. Spray pyrolysis of CZTS nanoplatelets.

    Science.gov (United States)

    Exarhos, S; Bozhilov, K N; Mangolini, L

    2014-10-01

    We demonstrate that copper-zinc-tin-sulphide nanoplatelets can be directly grown onto a molybdenum-coated substrate using spray pyrolysis starting from a mixture of metal thiocarbamates precursors. The structure and phase purity of the nanoplatelets is discussed in detail. PMID:25119262

  14. Physico-chemical, optical and electrochemical properties of iron oxide thin films prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Iron oxide thin films were prepared by spray pyrolysis technique onto glass substrates from iron chloride solution. They were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and (UV-vis) spectroscopy. The films deposited at T s ≤ 450 deg. C were amorphous; while those produced at T sub = 500 deg. C were polycrystalline α-Fe2O3 with a preferential orientation along the (1 0 4) direction. By observing scanning electron microscopy (SEM), it was seen that iron oxide films were relatively homogeneous uniform and had a good adherence to the glass substrates. The grain size was found (by RX) between 19 and 25 nm. The composition of these films was examined by X-ray photoelectron spectroscopy and electron probe microanalysis (EPMA). These films exhibited also a transmittance value about 80% in the visible and infrared range. The cyclic voltammetry study showed that the films of Fe2O3 deposited on ITO pre-coated glass substrates were capable of charge insertion/extraction when immersed in an electrolyte of propylene carbonate (PC) with 0.5 M LiCLO4

  15. Optical properties of TiO{sub 2} thin films prepared by chemical spray pyrolysis from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ayouchi, R.; Casteleiro, C.; Schwarz, R. [Departamento de Fisica, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Barrado, J.R.; Martin, F. [Laboratorio de Materiales y Superficie (Unidad Asociada al CSIC), Departamento de Fisica Aplicada I e Departamento de Ingenieria Quimica, Universidad de Malaga, 29071 Malaga (Spain)

    2010-04-15

    Titanium dioxide (TiO{sub 2}) is known to have three different kinds of polymorphous crystalline forms: rutile, anatase, and brookite. The rutile phase is always formed at higher temperatures, while the anatase phase is formed at lower temperatures and transformed into rutile phase above 800 C. Various deposition techniques have been developed for depositing TiO{sub 2} thin films, including evaporation, sputtering, chemical vapour deposition and thermal oxidation of titanium. Among them, the Chemical Spray Pyrolysis (CSP) technique has many advantages, such as good conformal coverage, the possibility of epitaxial growth and the application to large area deposition. Also, this method is low cost and it is easy to control the deposition growth parameters. In the present work, TiO{sub 2} thin films have been deposited on p-Si(001) and fused silica substrates by Chemical Spray Pyrolysis (CSP) method from aqueous solution containing titanium (IV) isopropoxide (Ti[OCH(CH{sub 3}){sub 2}]{sub 4}). As-deposited thin films show anatase polycrystalline structure, and rutile phase formed for films annealed at 750 C. SEM images have confirmed a smooth and crack-free surface with low surface roughness. X-ray photoelectron spectroscopy (XPS) combined with 4 keV Ar{sup +} depth profiling has shown that crystallized films correspond to TiO{sub 2}. Residual carbon coming from the organic precursor solution is only detected at the surface of the film. Thin films deposited on fused silica were highly transparent (more than 85%), with an indirect optical band gap of 3,43 and 3,33 eV for as-deposited and annealed films, respectively, and refractive indexes in the range between 2.01-2.29. Spectroscopic Ellipsometry (SE) also has been used to extract optical parameters. SE data fitted to triple-layer physical model revealed the same tendency to increase refractive index in annealed films. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Chemical composition and temperature dependent performance of ZnO-thin film transistors deposited by pulsed and continuous spray pyrolysis

    International Nuclear Information System (INIS)

    Zinc oxide thin film transistors (TFTs) deposited by continuous and pulsed spray pyrolysis were investigated to analyze process kinetics which make reduction of process temperature possible. Thus, fluid mechanics, chemical composition, electrical performance, and deposition and annealing temperature were systematically analyzed. It was found that ZnO layers continuously deposited at 360 °C contained zinc oxynitrides, CO3, and hydro carbonate groups from pyrolysis of basic zinc acetate. Statistically, every second wurtzite ZnO unit cell contained an impurity atom. The purity and performance of the ZnO-TFTs increased systematically with increasing deposition temperature due to an improved oxidation processes. At 500 °C the zinc to oxygen ratio exceeded a high value of 0.96. Additionally, the ZnO film was not found to be in a stabilized state after deposition even at high temperatures. Introducing additional subsequent annealing steps stabilizes the film and allows the reduction of the overall thermal stress to the substrate. Further improvement of device characteristics was obtained by pulsed deposition which allowed a more effective transport of the by-products and oxygen. A significant reduction of the deposition temperature by 140 °C was achieved compared to the same performance as in continuous deposition mode. The trap density close to the Fermi energy could be reduced by a factor of two to 4 × 1017 eV−1 cm−3 due to the optimized combustion process on the surface. The optimization of the deposition processes made the fabrication of TFTs with excellent performance possible. The mobility was high and exceeded 12 cm2/V s, the subthreshold slope was 0.3 V dec−1, and an on-set close to the ideal value of 0 V was achieved

  17. Synthesis of solid, spherical zirconia particles by spray pyrolysis

    International Nuclear Information System (INIS)

    A model is used to predict solid particle formation during spray pyrolysis by correlating droplet shrinkage before salt precipitation with its relative solution saturation. For the rapid drying conditions and droplet size of ∼10 μm, which are characteristic of conventional spray pyrolysis, solid salt particles are formed when a droplet's initial relative solution saturation is ∼10-2 and the precipitated salt is sufficiently permeable to permit evolution of the remaining solvent after precipitation. It is proposed that this concentration allows the drying droplet more time and a shorter diffusion distance in which to maintain chemical homogeneity before precipitation. Using these concepts it is demonstrated that zirconyl chloride (ZrOCl2 · 8H2O) and zirconyl hydroxychloride (ZrO(OH)Cl) are excellent zirconium salts for solid zirconia particle synthesis by spray pyrolysis

  18. Study of Structural and Optical Properties of Zinc Oxide Rods Grown on Glasses by Chemical Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Erdal Sonmez

    2012-01-01

    Full Text Available We have investigated morphological and optical properties of zinc oxide rods. Highly structured ZnO layers comprising with well-shaped hexagonal rods were prepared by spray pyrolysis deposition of zinc chloride aqueous solutions at ~550∘C. The rods were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, photoluminescence, and ultraviolet and visible absorption spectroscopy measurements. The deposition of the 0.1 mol/L solution at ~550∘C resulted in crystals with a diameter of 400–1000 nm and length of 500–2000 nm. Sharp near-band edge emission peaks, centered at 3844 and 3680 Å, dominated the PL spectra of ZnO at 300 K and 6.2 K, respectively. In addition to this, absorption coefficient was determined by absorption measurement. X-ray diffraction, scanning electron microscopy and atomic force microscopy, results suggest that ZnO rods, prepared by spray pyrolysis, have high crystalline quality. This is desirable in nanotechnology applications.

  19. Spray pyrolysis process for preparing superconductive films

    International Nuclear Information System (INIS)

    This paper describes a spray pyrolysis method for preparing thin superconductive film. It comprises: preparing a spray pyrolysis solution comprising Bi,Sr,Ca and Cu metals in a solvent; heating a substrate to a first temperature; spraying the solution onto the heated substrate to form a film thereon; heating the film and substrate to a second temperature of about 700 degrees-825 degrees C, the second temperature being higher than the first temperature; heating the film and substrate to a third temperature of about 870 degrees-890 degrees C to melt the film; once the film and substrate reach the third temperature, further heat treating the film and substrate; cooling the film and substrate to ambient temperature. This patent also describes a spray pyrolysis method for preparing thin superconductive films. It comprises: preparing a spray pyrolysis solution comprising Bi, Ca and Cu metals and fluxing agent in a solvent; heating a substrate to a first temperature; spraying the solution onto the heated substrate to form a film thereon; heating the film and substrate to a second temperature about 700 degrees-825 degrees C, the second temperature being higher than the first temperature; heating the film and substrate at a third temperature about 840 degrees-860 degrees C; and cooling the film and substrate to ambient temperature

  20. XRD and XPS characterization of mixed valence Mn3O4 hausmannite thin films prepared by chemical spray pyrolysis technique

    International Nuclear Information System (INIS)

    Spray pyrolysis technique has been employed successfully for the synthesis of single phase mixed valence spinel hausmannite (Mn3O4) thin films using alcoholic start solution of manganese acetate (Mn(CH3COO)2.4H2O) on pyrex glass substrates at atmospheric pressure using air as a carrier gas. Thermal decomposition of the precursor in the temperature range 320-490 deg. C led to the formation of Mn3O4 phase as revealed from the thermogravimetry analysis. Prepared samples are characterized by X-ray diffraction that shows spinel structure with space group I41/amd. Pure and well crystallized specimen is subjected to X-ray photoelectron spectroscopy for the surface chemistry investigation of these systems at a molecular level. Surface Mn/O ratio is compared to the bulk composition of the sample. Atomic force micrographs revealed that the morphology and the surface grains of the films largely influenced by the substrate temperature.

  1. Epitaxial growth of high T/sub c/ superconducting Y-Ba-Cu-O thin films on (001)MgO by a chemical spray pyrolysis method

    International Nuclear Information System (INIS)

    A chemical spray pyrolysis method has been applied to grow epitaxial films of a high T/sub c/ Y-Ba-Cu-O compound (YBCO) on (001)MgO. Films as thin as 0.6 μm in thickness was found to exhibit excellent superconducting transition behavior. For films up to 2 μm in thickness, typical values of T/sub c/ onset, T/sub c/ zero and transition width (90%--10%) were measured to be 82, 76, and 1.5 K, respectively. Both plan-view and cross-sectional transmission electron microscopy revealed that the orientation relationships between the epitaxial films and the substrate are [001]YBCO//[001]MgO and (110)YBCO//(200)MgO. Twins, which may be perceived as domains that are rotated 900 along the c axis of the thin films with respect to the substrate, were found to be copiously present. The influences of the configuration of the oriented growth of overlayer thin films on the superconducting properties are addressed. The advantages of the chemical spray pyrolysis in producing superconducting thin films are outlined

  2. Producing Quantum Dots by Spray Pyrolysis

    Science.gov (United States)

    Banger, Kulbinder; Jin, Michael H.; Hepp, Aloysius

    2006-01-01

    An improved process for making nanocrystallites, commonly denoted quantum dots (QDs), is based on spray pyrolysis. Unlike the process used heretofore, the improved process is amenable to mass production of either passivated or non-passivated QDs, with computer control to ensure near uniformity of size.

  3. Structural, optical and electrical properties of Cu2FeSnX4 (X = S, Se) thin films prepared by chemical spray pyrolysis

    International Nuclear Information System (INIS)

    Highlights: • CFTS(Se) thin films have been synthesized by low-cost spray-based deposition. • The fabricated films were found to be of stannite structure and p-type conductivity. • Band gaps of CFTS and CFTSe thin films are 1.37 and 1.11 eV, respectively. - Abstract: We report on fabrication of polycrystalline Cu2FeSnX4 (X = S, Se) thin films by chemical spray pyrolysis subsequent with post-sulfurization and selenization. The post-annealing of as-sprayed Cu2FeSnS4 (CFTS) films in sulfur and selenium ambient demonstrated drastically improved surface texture as well as crystallinity. The crystal lattice parameters calculated from X-ray diffraction patterns for post-annealed films were found to be consistent with stannite structure. The fabricated Cu2FeSnS4 (CFTS) and Cu2FeSnSe4 (CFTSe) films showed p-type conductivity with carrier concentration in the range of 1021 cm−3 and mobility ∼1–5 cm2 V−1 s−1. The band gap energies of post-sulfurized CFTS and post-selenized CFTSe films were estimated to be ∼1.37 eV and ∼1.11 eV with an error of ±0.02 eV by UV–Vis absorption, respectively, which are promising for photovoltaic application

  4. UVC emitting phosphors obtained by spray pyrolysis

    International Nuclear Information System (INIS)

    The broadband inter-configurational (4f15d1→4f2) emission of Pr3+ doped in lanthanum orthophosphate (LaPO4) and in calcium pyrophosphate (Ca2P2O7) has been investigated under plasma excitation. The synthesis by spray pyrolysis at moderate temperature followed by a controlled annealing proves to be a very efficient way to produce good quality UVC emitting phosphor Ca1.92Pr0.04Na0.04P2O7 (α phase). The emission of this phosphor in the wavelength range 200-350 nm has been measured with a prototype device, which can be employed for anti-microbial testing. - Research Highlights: → The Pr3+ doped orthophosphate and pyrophosphate were synthesized by spray pyrolysis. → The dense particles present good quality UVC emitting (200-350 nm). → The prototype device can be employed for anti-microbial testing.

  5. Compositional and physico-optical characterization of 0-5% Al-doped zinc oxide films prepared by chemical spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Romero, R; Lopez-Ibanez, R; Ramos-Barrado, J R; Martin, F; Leinen, D [Laboratorio de Materiales y Superficie (Unidad Asociada al CSIC), Dpto. Fisica Aplicada I and Dpto. IngenierIa Quimica, Universidad de Malaga, E-29071 Malaga (Spain); Dalchiele, E A, E-mail: dietmar@uma.e [Instituto de Fisica, Facultad de IngenierIa, Universidad de la Republica, Herrera y Reissig 565, C.C. 30, 11000 Montevideo (Uruguay)

    2010-03-10

    Highly transparent polycrystalline Al-doped ZnO thin films were deposited in open atmosphere by chemical spray pyrolysis on fused silica and glass substrates at 623 K. The influence of Al doping, 0 to 5%, was studied. XPS results revealed a linear relationship between Al content in the precursor solutions and Al content in the films. XPS depth profiling showed that any carbon contamination is restricted to the uppermost surface of the films. Optical transmission measurements revealed an increasing number of dispersion centres as well as a band gap shift to higher values with increasing Al content in the films. At fixed Al concentration, the comparison of the absorption coefficient for increasing film thickness showed that the films are very homogeneous, not changing their materials properties such as absorption coefficient and band gap.

  6. Structural, optical and electrical properties of Cu{sub 2}FeSnX{sub 4} (X = S, Se) thin films prepared by chemical spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Khadka, Dhruba B.; Kim, JunHo, E-mail: jhk@inu.ac.kr

    2015-07-25

    Highlights: • CFTS(Se) thin films have been synthesized by low-cost spray-based deposition. • The fabricated films were found to be of stannite structure and p-type conductivity. • Band gaps of CFTS and CFTSe thin films are 1.37 and 1.11 eV, respectively. - Abstract: We report on fabrication of polycrystalline Cu{sub 2}FeSnX{sub 4} (X = S, Se) thin films by chemical spray pyrolysis subsequent with post-sulfurization and selenization. The post-annealing of as-sprayed Cu{sub 2}FeSnS{sub 4} (CFTS) films in sulfur and selenium ambient demonstrated drastically improved surface texture as well as crystallinity. The crystal lattice parameters calculated from X-ray diffraction patterns for post-annealed films were found to be consistent with stannite structure. The fabricated Cu{sub 2}FeSnS{sub 4} (CFTS) and Cu{sub 2}FeSnSe{sub 4} (CFTSe) films showed p-type conductivity with carrier concentration in the range of 10{sup 21} cm{sup −3} and mobility ∼1–5 cm{sup 2} V{sup −1} s{sup −1}. The band gap energies of post-sulfurized CFTS and post-selenized CFTSe films were estimated to be ∼1.37 eV and ∼1.11 eV with an error of ±0.02 eV by UV–Vis absorption, respectively, which are promising for photovoltaic application.

  7. Direct spray pyrolysis of aluminum chloride solution for alumina preparation

    Institute of Scientific and Technical Information of China (English)

    吕国志; 张廷安; 王龙; 马思达; 豆志河; 刘燕

    2014-01-01

    The effects of pyrolysis mode and pyrolysis parameters on Cl content in alumina were investigated, and the alumina products were characterized by XRD, SEM and ASAP. The experimental results indicate that the spray pyrolysis efficiency is higher than that of static pyrolysis process, and the reaction and evaporation process lead to a multi-plot state of the alumina products by spray pyrolysis. Aluminum phase starts to transform intoγ-Al2O3 at spray pyrolysis temperature of 600 °C, which is about 200 °C lower than that of static pyrolysis process. The primary particle size of γ-Al2O3 product is 27.62 nm, and Cl content in alumina products is 0.38%at 800 °C for 20 min.

  8. Rutherford Backscattering Spectrometry Analysis and Structural Properties of ZnxPb1-xS Thin Films Deposited by Chemical Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Abiodun E. Adeoye

    2015-01-01

    Full Text Available Zinc lead sulphide ternary thin films were prepared by chemical spray pyrolysis on soda lime glass substrates using zinc acetate, lead acetate, and thiourea sources precursor. The films were characterized using Rutherford backscattering (RBS spectrometry, energy dispersive X-ray (EDX spectroscopy, scanning electron microscopy (SEM, and X-ray diffractometry (XRD. RBS studies revealed variation in thickness and stoichiometry of the films with respect to compositional substitution between Zn and Pb, thereby giving effective composition ZnxPb1-xS, where x=0, 0.035, 0.069, 0.109, 0.176, and 0.217. Film thickness obtained by length conversion ranged from 81.02 nm to 90.03 nm. Microstructural analyses also indicated that the growth and particle distribution of the films were uniform across substrate’s surface. Diffraction studies showed that the films possess FCC crystalline structure. Crystallite size reduced from 14.28 to 9.8 nm with increase in Zn2+ in the ZnxPb1-xS samples.

  9. Multicomponent ceramic powder generation by spray pyrolysis

    International Nuclear Information System (INIS)

    This paper reports that the authors examined methods for controlling the morphology and microstructure of ceramic particles produced by spray pyrolysis. A variety of materials were examined including SrTiO3 and BaTiO3 and the oxides of Al, Mg, Zn, Pd, V, Mo, and Bi. The morphology of the particles was influenced by using colloidal precursors in combination with molecular precursors for particle generation. Slow drying rates obtained by using high relative humidities and controlled axial temperature gradients did not influence particle morphology for the systems and conditions studied. The microstructure of Al2O3, Bi2O3, V2O5, and PdO particles was controlled by varying the temperature to provide nanocrystalline or single-crystal particles. Evaporation and condensation of volatile species such as MoO3 and V2O5 dramatically modified particle microstructure and morphology

  10. Synthesis of Nanowires by Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Kalyana C. Pingali

    2009-01-01

    Full Text Available Nanowires of carbon as well as nickel-carbon (Ni-C were synthesized by spray-pyrolysis. The carbon nanowires were synthesized using methanol as a precursor while the Ni-C nanowires were obtained by using nickel chloride methanol solution as feed. It was found that low argon carrier gas flow rates (<100 cm3/min and suitable reaction temperatures (∼700∘C were found to be critical for the formation of wired structures. The formation of nanowires was quite sensitive to reaction temperature. Nanowires could not form at temperatures higher than 900∘C in the presence of hexane. Ruthenium chloride and nickel chloride dissolved in hexane and methanol resulted in carbon coated binary metallic nanoparticles. Morphological differences of carbon nanowires, Ni-C wires and carbon coated binary nanoparticles were characterized by scanning electron microscopy (SEM and energy-dispersive X-ray analysis (EDS. The formation mechanism for the wired structures is proposed to explain the structural results obtained.

  11. Photoluminescence of spray pyrolysis deposited ZnO nanorods

    Directory of Open Access Journals (Sweden)

    Mikli Valdek

    2011-01-01

    Full Text Available Abstract Photoluminescence of highly structured ZnO layers comprising well-shaped hexagonal rods is presented. The ZnO rods (length 500-1,000 nm, diameter 100-300 nm were grown in air onto a preheated soda-lime glass (SGL or ITO/SGL substrate by low-cost chemical spray pyrolysis method using zinc chloride precursor solutions and growth temperatures in the range of 450-550°C. We report the effect of the variation in deposition parameters (substrate type, growth temperature, spray rate, solvent type on the photoluminescence properties of the spray-deposited ZnO nanorods. A dominant near band edge (NBE emission is observed at 300 K and at 10 K. High-resolution photoluminescence measurements at 10 K reveal fine structure of the NBE band with the dominant peaks related to the bound exciton transitions. It is found that all studied technological parameters affect the excitonic photoluminescence in ZnO nanorods. PACS: 78.55.Et, 81.15.Rs, 61.46.Km

  12. Flame spray pyrolysis synthesis and aerosol deposition of nanoparticle films

    DEFF Research Database (Denmark)

    Tricoli, Antonio; Elmøe, Tobias Dokkedal

    2012-01-01

    The assembly of nanoparticle films by flame spray pyrolysis (FSP) synthesis and deposition on temperature‐controlled substrates (323–723 K) was investigated for several application‐relevant conditions. An exemplary SnO2 nanoparticle aerosol was generated by FSP and its properties (e.g., particle...

  13. Nanoparticle synthesis using flame spray pyrolysis for catalysis

    DEFF Research Database (Denmark)

    Høj, Martin

    processes based on renewable feedstock, new or improved ways of preparing catalysts and a better understanding of the catalyst structure at operating conditions. This thesis explores flame spray pyrolysis (FSP) as a novel one-step preparation method for heterogeneous catalysts and investigates structure...

  14. Preparation of YBCO superconducting films by spray pyrolysis method

    International Nuclear Information System (INIS)

    The methodology for the preparation of YBCO superconducting films on Zr2O(Y) substrates by spray pyrolysis method is reported. The transition temperature of these films is superior than the boiling temperature of liquid 2N. Other critical parameters are similar to those reported by other authors using the same technique

  15. CuInS2 thin films obtained by spray pyrolysis for photovoltaic applications

    International Nuclear Information System (INIS)

    Copper indium disulphide, CuInS2, is a promising absorber material for thin film photovoltaic which has recently attracted considerable attention due to its suitability to reach high efficiency solar cells by using low-cost techniques. In this work CuInS2 thin films have been deposited by chemical spray pyrolysis onto glass substrates at ambient atmosphere, using different composition solutions at various substrate temperatures. Structural, chemical composition and optical properties of CIS films were analysed by X-ray diffraction, energy dispersive X-ray spectroscopy and optical spectroscopy. Sprayed CIS films are polycrystalline with a chalcopyrite structure with a preferential orientation along the direction and no remains of oxides were found after spraying in suitable conditions. X-ray microanalysis shows that a chemical composition near to stochiometry can be obtained. An optical gap of about 1.51 eV was found for sprayed CIS thin films

  16. Spray pyrolysis deposition of indium sulphide thin films

    International Nuclear Information System (INIS)

    In2S3 thin films were grown by the chemical spray pyrolysis (CSP) method using the pneumatic spray set-up and compressed air as a carrier gas. Aqueous solutions containing InCl3 and SC(NH2)2 at a molar ratio of In/S = 1/3 and 1/6 were deposited onto preheated glass sheets at substrate temperatures Ts = 205-410 oC. The obtained films were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM,) optical transmission spectra, X-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS). According to XRD, thin films deposited at Ts = 205-365 oC were composed of the (0 0 12) orientated tetragonal β-In2S3 phase independent of the In/S ratio in the spray solution. Depositions performed at Ts = 410 oC led to the formation of the In2O3 phase, preferably when the 1/3 solution was sprayed. Post-deposition annealing in air indicated that oxidation of the sulphide phase has a minor role in the formation of In2O3 at temperatures up to 450 oC. In2S3 films grown at Ts below 365 oC exhibited transparency over 70% in the visible spectral region and Eg of 2.90-2.96 eV for direct and 2.15-2.30 eV for indirect transitions, respectively. Film thickness and chlorine content decreased with increasing deposition temperatures. The XPS study revealed that the In/S ratio in the spray solution had a significant influence on the content of oxygen (Me-O, BE = 530.0 eV) in the In2S3 films deposited in the temperature range of 205-365 oC. Both XPS and EDS studies confirmed that oxygen content in the films deposited using the solution with the In/S ratio of 1/6 was substantially lower than in the films deposited with the In/S ratio of 1/3.

  17. Comparison of SnO2/Si-n Thin Films Deposited by Pneumatic Spray Pyrolysis Technique with that Deposited by Ultrasonic Spray Pyrolysis Technique

    International Nuclear Information System (INIS)

    Pneumatic Spray Pyrolysis (PSP) technique has been generally used to grow low cost transparent conducting oxide/TCO films involving various interesting materials such as tin oxide/ SnO2, indium tin oxide/ITO and zinc oxide/ZnO. The PSP is widely acceptable because of its cost effectiveness, simple operation, easy doping etc. Since the emerging of ultrasonic spray pyrolysis (USP) technique, attention has been given more on this technique because of several advantageous over the PSP technique such as low pressure, lower consumption of source material, lower of overspray material so reduce the contamination around and also results in unclog nozzle. In this paper, we report the SnO2/Si-n thin films deposition using these two techniques by evaluate both parameter process (source materials, substrate temperature, requirement for catalyst chemicals etc.) and the resulted SnO2/Si-n thin film properties (structural, electrical and optical properties). We compare SnO2/Si-n best thin film samples obtained from both experiments under optimum experimental condition and evaluate them. In conclusion, the Ultrasonic Spray Pyrolysis technique, using the same quantity of source materials to grow the SnO2/Si-n thin film, results in same quality of tin oxide polycrystal with almost equal resistivity and homogeneity, need less consumption of source materials up to 80 %, lower required temperature (50 - 100) oC and simpler catalyst/less toxic compared with Pneumatic Spray Pyrolysis technique. The USP system here is being developed further to produce various thin films for energy devices (for example solar cell and fuel cell). (author)

  18. Preparation of doping titania antibacterial powder by ultrasonic spray pyrolysis

    Institute of Scientific and Technical Information of China (English)

    WEI Shun-wen; PENG Bing; CHAI Li-yuan; LIU Yun-chao; LI Zhu-ying

    2008-01-01

    Doping titania powders were synthesized by ultrasonic spray pyrolysis method from an aqueous solution containing H2TiF6 and AgNO3. The effects of the processing parameters on panicle size distribution, structure, and morphology of doping panicles were investigated. The results show that aggregation-free spherical panicles with average diameter of 200-600 nm are obtained and the particle size of the powder can be controlled by adjusting the concentration of solution. The experimental approach indicates that the size and the value of standard deviation of panicle size increase from 210 nm to 450 nm and from 0.46 to 0.73 respectively with the increase of the titanic ion concentration from 0.05 to 0.4 mol/L. Composite TiOF2 is obtained when the pyrolysis temperature is set to be 400 ℃. With increasing pyrolysis temperature from 400 ℃ to 800 ℃, the crystal size of titania powders increases from 14.1 to 26.5 nm and TiOF2 content of powder decreases dramatically. The property of ion released from powder is affected significantly by the pyrolysis temperature, and the amount of fluorine ion and silver ion released from powder decrease with increasing pyrolysis temperature. The optical property of doping titania powders is not affected by pyrolysis temperature. Antibacterial test results show that composite powders containing more fluorine ions exhibit stronger antibacterial activity against E.coli.

  19. Magnetic-luminescent spherical particles synthesized by ultrasonic spray pyrolysis

    Science.gov (United States)

    Michel, Norma L.; Flores, Dora L.; Hirata, Gustavo A.

    2015-07-01

    The combination of magnetic and luminescent properties in a single particle system, opens-up a wide range of potential applications in biotechnology and biomedicine. In this work, we performed the synthesis of magnetic-luminescent Gd2O3:Eu3+@Fe2O3 particles by ultrasonic spray pyrolysis performed in a tubular furnace. In order to achieve the composite formation, commercial superparamagnetic Fe3O4 nanoparticles were coated with a luminescent Eu3+-doped Gd2O3 shell in a low-cost one-step process. The spray pyrolysis method yields deagglomerated spherical shape magneto/luminescent particles. The photoluminescence spectra under UV excitation (λExc = 265 nm) of the magnetic Gd2O3:Eu3+@Fe2O3 compound showed the characteristic red emission of Eu3+ (λEm = 612 nm). This magneto/luminescent system will find applications in biomedicine and biotechnology.

  20. Structural, morphological, optical and opto-thermal properties of Ni-doped ZnO thin films using spray pyrolysis chemical technique

    Indian Academy of Sciences (India)

    S Rajeh; A Barhoumi; A Mhamdi; G Leroy; B Duponchel; M Amlouk; S Guermazi

    2016-02-01

    Nickel-doped zinc oxide thin films (ZnO : Ni) at different percentages were deposited on glass substrates using a chemical spray technique. The effect of Ni concentration on the structural, morphological, optical and photoluminescence (PL) properties of the ZnO : Ni thin films were investigated. X-ray diffraction analysis revealed that all films consist of single phase ZnO and was well crystallized in würtzite phase with the crystallites preferentially oriented towards the (002) direction parallel to the c-axis. The optical transmittance measurement was found to be higher than 90%, the optical band gap values of ZnO thin films decreased after doping from 3.29 to 3.21 eV. A noticeable change in optical constants was observed between undoped and Ni-doped ZnO. Room-temperature PL is observed for ZnO, and Ni-doped ZnO thin films.

  1. Aerosol spray pyrolysis & solution phase synthesis of nanostructures

    Science.gov (United States)

    Zhang, Hongwang

    This dissertation focuses on the synthesis of nanomaterials by both solution phase and gas phase methods. By the solution phase method, we demonstrate the synthesis of Au/CdS binary hybrid nanoparticles and the Au-induced growth of CdS nanorods. At higher reaction temperature, extremely uniform CdS nanorods were obtained. The size of the Au seed nanoparticles has an important influence on the length and diameter of the nanorods. In addition, preparation of peanut-like FePt-CdS hybrid nanoparticles by spontaneous epitaxial nucleation and growth of CdS onto FePt-seed nanoparticles in high-temperature organic solution is reported. The FePt-CdS hybrid nanoparticles reported here are an example of a bifunctional nanomaterial that combines size-dependent magnetic and optical properties. In the gas phase method, a spray pyrolysis aerosol synthesis method was used to produce tellurium dioxide nanoparticles and zinc sulfide nanoparticles. Tellurite glasses (amorphous TeO2 based materials) have two useful optical properties, high refractive index and high optical nonlinearity, that make them attractive for a range of applications. In the work presented here, TeO2 nanoparticles were prepared by spray pyrolysis of an aqueous solution of telluric acid, Te(OH)6. This laboratory-scale process is capable of producing up to 80 mg/hr of amorphous TeO2-nanoparticles with primary particle diameters from 10 to 40 nm, and allows their synthesis in significant quantities from an inexpensive and environmentally friendly precursor. Furthermore, both Er3+ doped and Er3+ and Yb3+ co-doped tellurium dioxide nanoparticles were synthesized by spray pyrolysis of an aqueous mixture of telluric acid with erbium/ytterbium salts, which exhibit the infrared to green visible upconversion phenomena. ZnS nanoparticles (NPs) were prepared by spray pyrolysis using zinc diethyldithiocarbamate as a single-source precursor. The home-built scanning mobility particle spectrometer (SMPS) is a useful tool for

  2. Barium strontium titanate powders prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Ultasonic spray pyrolysis (SP) has been investigated for the production of the barium strontium titanate (BST) powders from the polymeric precursors. The processing parameters, such as flux of aerosol and temperature profile inside the furnace, were optimized to obtain single phase BST. The powders were characterized by the methods of X-ray diffraction analysis, SEM, EDS and TEM. The obtained powders were submicronic, consisting of spherical, polycrystalline particles, with internal nanocrystalline structure. Crystallite size of 10 nm, calculated using Rietveld refinement, is in a good agreement with results of HRTEM

  3. CuS Thin Films Obtained by Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Violeta POPESCU

    2004-02-01

    Full Text Available The paper presents a study concerning the influence of deposition parameters (reagents, electron donors, surfactants, temperature of the substrate, number of consecutive layers, spraying rate on the quality of CuS thin films achieved by spray pyrolysis on glass substrate, from solutions containing CuCl2·2H2O, thiourea, electron pair donors and surfactants. As electron pairs donors ammonia and triethanolamine were used and as surfactants C12 - C14 ether-sulphate, sodium lauryl-sulphate and cetyl-pyridinium bromide were used. The optimum conditions for the obtaining of optically clear, compact and adherent CuS thin films, showing different colors in reflected light (violet, yellow, brawn, green and exhibiting in VIS and NIR light appropriate reflectance and transmittance for utilization for solar control applications were established. The film thickness falls in the range 10- 50 nm.

  4. Chemical spray pyrolysis of Tl-Ba-Ca-Cu-O high-T(sub c) superconductors for high-field bitter magnets

    Science.gov (United States)

    Derochemont, L. Pierre; Zhang, John G.; Squillante, Michael R.; Hermann, A. M.; Duan, H. M.; Andrews, Robert J.; Kelliher, Warren C.

    1991-01-01

    The deposition of Tl-Ba-Ca-Cu-O thick films by spray pyrolyzing a Ba-Ca-Cu-O precursor film and diffusing thallium into the film to form the superconducting phase is examined. This approach was taken to reduce exposure to thallium and its health and safety hazards. The Tl-Ba-Ca-Cu-O system was selected because it has very attractive features which make it appealing to device and manufacturing engineering. Tl-Ba-Ca-Cu-O will accommodate a number of superconducting phases. This attribute makes it very forgiving to stoichiometric fluctuations in the bulk and film. It has excellent thermal and chemical stability, and appears to be relatively insensitive to chemical impurities. Oxygen is tightly bound into the systems, consequently there is no orthorhombic (conductor) to tetragonal (insulator) transition which would affect a component's lifetime. More significantly, the thallium based superconductors appear to have harder magnetic properties than the other high-Tc oxide ceramics. Estimates using magnetoresistance measurements indicate that at 77 K Tl2Ba2CaCu2O10 will have an upper critical field, H(sub c2) fo 26 Tesla for applied fields parallel to the c-axis and approximately 1000 Tesla for fields oriented in the a-b plane. Results to date have shown that superconducting films can be reproducibly deposited on 100 oriented MgO substrates. One film had a zero resistance temperature of 111.5 K. Furthermore, x ray diffraction analysis of the films showed preferential c-axis orientation parallel to the plane of the substrate. These results have now made it possible to consider the manufacture of a superconducting tape wire which can be configured into a topology useful for high-field magnet designs. The research which leads to the preparation of these films and plans for further development are reviewed.

  5. Preparation of supported copper catalyst by spray pyrolysis of copper acetate on HEU zeolite

    International Nuclear Information System (INIS)

    Bulgarian natural clinoptilolite was coated with copper and its oxides via spray pyrolysis method. D.C. arc-AES method revealed the presence of copper atoms. XRD patterns showed that after loading the Heulandite-type (HEU-type) structure is preserved. It is also proved that several copper phases exist on the zeolite: Cu, CuO and Cu2O. The chemical content of natural and coated zeolite forms has been proved by XPS analysis. Scanning Electron Microscopy (SEM) revealed Cu nanoparticles situated over the zeolite surface as agglomerates. The ozone conversion on the copper supported catalyst reaches 87% and does not change with the course of time

  6. Thin Film CuInS2 Prepared by Spray Pyrolysis with Single-Source Precursors

    Science.gov (United States)

    Jin, Michael H.; Banger, Kulinder K.; Harris, Jerry D.; Cowen, Jonathan E.; Hepp, Aloysius F.; Lyons, Valerie (Technical Monitor)

    2002-01-01

    Both horizontal hot-wall and vertical cold-wall atmospheric chemical spray pyrolysis processes deposited near single-phase stoichiometric CuInS2 thin films. Single-source precursors developed for ternary chalcopyrite materials were used for this study, and a new liquid phase single-source precursor was tested with a vertical cold-wall reactor. The depositions were carried out under an argon atmosphere, and the substrate temperature was kept at 400 C. Columnar grain structure was obtained with vapor deposition, and the granular structure was obtained with (liquid) droplet deposition. Conductive films were deposited with planar electrical resistivities ranging from 1 to 30 Omega x cm.

  7. Spherical YAG:Ce3+ Phosphor Particles Prepared by Spray Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    Qi Faxin; Wang Haibo; Zhu Xianzhong

    2005-01-01

    Spherical YAG:Ce3+ phosphor particles with narrow size distribution were prepared by spray pyrolysis. The effects of the concentration of solution, the flow rate of carrier gas and the annealing temperature on the phosphor morphology were studied. The productivity of precursor particles shows a trend of drop after rising with the increase of concentration. Raising the flow rate of nitrogen can improve the productivity of the precursor particles. Phosphor prepared by spray pyrolysis has obviously higher emission intensity than that synthesized by solid state reaction, spray pyrolysis makes Ce3+ ions well distributed in the crystal lattice as the luminescent centers, and phosphor particles have regular sphericity and narrow size distribution.

  8. SnS2 Thin Film Deposition by Spray Pyrolysis

    Science.gov (United States)

    Yahia Jaber, Abdallah; Noaiman Alamri, Saleh; Salah Aida, Mohammed

    2012-06-01

    Tin disulfide (SnS2) thin films have been synthesized using a simplified spray pyrolysis technique using a perfume atomizer. The films were deposited using two different solutions prepared by the dilution of SnCl2 and thiourea in distilled water and in methanol. The obtained films have a microcrystalline structure. The film deposited using methanol as the solvent is nearly stochiometric SnS2 with a spinel phase having a (001) preferential orientation. The film prepared with an aqueous solution is Sn-rich. Scanning electronic microscopy (SEM) images reveal that the film deposited with the aqueous solution is rough and is formed with large wires. However, the film deposited with methanol is dense and smooth. Conductivity measurements indicate that the aqueous solution leads to an n-type semiconductor, while methanol leads to a p-type semiconductor.

  9. Isotype bifacial silicon solar cells obtained by ITO spray pyrolysis

    International Nuclear Information System (INIS)

    In this work we realized a new kind of bifacial solar cell with two isotype junctions based on the semiconductor-insulator-semiconductor structure. These devices were fabricated on nSi Cz wafers; the front junction was realized depositing ITO using the spray pyrolysis technique. A back surface field region was obtained by a P-diffusion process at the rear contact. To better evaluate the effectiveness of the rear side, we compared the performances of the latter cell with monofacial one having the same front junction, but with an extended metal contact on the rear surface of the wafer. All the devices were characterized by IV light, IV dark and quantum yield. The best bifacial cell realized in our laboratory achieved the efficiency of 9.0% (front side illumination) and 3.6% (rear side illumination), while the efficiency for the best monofacial solar cell was 9.6%.

  10. Isotype bifacial silicon solar cells obtained by ITO spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Bruk, L.; Fedorov, V.; Sherban, D.; Simashkevich, A. [Institute of Applied Physics, str. Academiei 5, MD 2028, Chisinau (Moldova, Republic of); Usatii, I. [Institute of Applied Physics, str. Academiei 5, MD 2028, Chisinau (Moldova, Republic of); C.R. ENEA Portici, Loc. Granatello, 80055 Portici (Italy)], E-mail: usaty1980@mail.ru; Bobeico, E.; Morvillo, P. [C.R. ENEA Portici, Loc. Granatello, 80055 Portici (Italy)

    2009-03-15

    In this work we realized a new kind of bifacial solar cell with two isotype junctions based on the semiconductor-insulator-semiconductor structure. These devices were fabricated on nSi Cz wafers; the front junction was realized depositing ITO using the spray pyrolysis technique. A back surface field region was obtained by a P-diffusion process at the rear contact. To better evaluate the effectiveness of the rear side, we compared the performances of the latter cell with monofacial one having the same front junction, but with an extended metal contact on the rear surface of the wafer. All the devices were characterized by IV light, IV dark and quantum yield. The best bifacial cell realized in our laboratory achieved the efficiency of 9.0% (front side illumination) and 3.6% (rear side illumination), while the efficiency for the best monofacial solar cell was 9.6%.

  11. The NO2 sensing ITO thin films prepared by ultrasonic spray pyrolysis

    OpenAIRE

    Jianzhong Gu; Minghua Lu; Zheng Qin; Minghong Wu; Zheng Jiao

    2003-01-01

    In this paper ITO thin films were deposited on alumina substrates by ultrasonic spray pyrolysis. The NO2 sensing properties of ITO thin films were investigated. The results show ITO thin films have good sensitivity to nitrogen dioxide.

  12. Synthesis of MgO Nanoparticles by Solvent Mixed Spray Pyrolysis Technique for Optical Investigation

    OpenAIRE

    Nemade, K. R.; S. A. Waghuley

    2014-01-01

    Solvent mixed spray pyrolysis technique has attracted a global interest in the synthesis of nanomaterials since reactions can be run in liquid state without further heating. Magnesium oxide (MgO) is a category of the practical semiconductor metal oxides, which is extensively used as catalyst and optical material. In the present study, MgO nanoparticles were successfully synthesized using a solvent mixed spray pyrolysis. The X-ray diffraction pattern confirmed the formation of MgO phase with a...

  13. Fabrication of functional nanomaterials using flame assisted spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Purwanto, Agus, E-mail: aguspur@uns.ac.id [Chemical Engineering Department, Faculty of Engineering, Sebelas Maret University, Surakarta 632112 (Indonesia)

    2014-02-24

    Flame assisted spray pyrolysis (FASP) is a class of synthesis method for nanomaterials fabrication. The ability to control nanomaterials characteristics and easy to be-scaled up are the main features of FASP. The crystallinity and particles size of the prepared nanomaterials can be easily controlled by variation of fuel flow rate. The precursor concentration, carrier gas flow rate, and carrier gas can be also used to control the prepared nanomaterials. Energy related nanomaterials preparation uses as the example case in FASP application. These material are yttrium aluminum garnet (YAG:Ce) and tungsten oxide (WO{sub 3}). It needs strategies to produce these materials into nano-sized order. YAG:Ce nanoparticles only can be synthesized by FASP using the urea addition. The decomposition of urea under high temperature of flame promotes the breakage of YAG:Ce particles into nanoparticles. In the preparation of WO{sub 3}, the high temperature flame can be used to gasify WO{sub 3} solid material. As a result, WO{sub 3} nanoparticles can be prepared easily. Generally, to produce nanoparticles via FASP method, the boiling point of the material is important to determine the strategy which will be used.

  14. Study of the influence of substrate temperature on structural, optical, and electrical properties of Zn-doped MnIn2S4 thin films prepared by chemical spray pyrolysis

    Science.gov (United States)

    Kennedy, A.; Viswanathan, K.; Pradeev raj, K.

    2016-08-01

    The Zn-doped MnIn2S4 thin films were deposited by chemical spray pyrolysis technique on a heated glass substrate using the aqueous solution of MnCl2, InCl3, (NH2)2CS and ZnCl2. The thin films were grown at different substrate temperatures ranging from 250-400 °C. The synthesized films were characterized by X-ray diffraction (XRD), energy dispersive analysis spectrum (EDS), field emission scanning electron microscope (FESEM), UV-Vis absorption spectroscopy and four probe method. The XRD analysis indicates Zn-doped MnIn2S4 thin films were polycrystalline in nature with a cubic spinel structure having (101) plane as the preferred orientation. The structural parameters like crystalline size (D), dislocation density (δ), strain (ε) and lattice distortion (LD) have been evaluated from XRD results. The energy dispersive analysis spectrum (EDS) predicts the presence of Mn, In, S and Zn in the film grown at 250 °C. The formation of the needle and spherical shaped grains was clearly observed from FE-SEM analysis. From the optical studies, it is analyzed that about (88%) of light transmission occurs in the Vis-IR regions. It is interesting to note that the structural homogeneity and crystallinity of the films has improved due to the decrease in the absorption coefficient (α) and extinction coefficient (K) with an increase in substrate temperature. The calculated optical band gap energies increase (1.51-1.74 eV) with an increase of substrate temperatures. The photoluminescence (PL) spectrum reveals the presence of well-defined band edge (<400 nm) and defect emissions in the wavelength region around 400-650 nm. Moreover, from electrical studies, the electrical resistivity decreases with increase in substrate temperature and a minimum electrical resistivity of 1.20 ×103 Ωm was obtained for the film coated at 400 °C. The high absorption coefficient (α) in the order of 104cm-1 and high transmittance (88%) of the films makes them an efficient absorber and a good window

  15. Effect of precursor concentration and spray pyrolysis temperature upon hydroxyapatite particle size and density.

    Science.gov (United States)

    Cho, Jung Sang; Lee, Jeong-Cheol; Rhee, Sang-Hoon

    2016-02-01

    In the synthesis of hydroxyapatite powders by spray pyrolysis, control of the particle size was investigated by varying the initial concentration of the precursor solution and the pyrolysis temperature. Calcium phosphate solutions (Ca/P ratio of 1.67) with a range of concentrations from 0.1 to 2.0 mol/L were prepared by dissolving calcium nitrate tetrahydrate and diammonium hydrogen phosphate in deionized water and subsequently adding nitric acid. Hydroxyapatite powders were then synthesized by spray pyrolysis at 900°C and at 1500°C, using these calcium phosphate precursor solutions, under the fixed carrier gas flow rate of 10 L/min. The particle size decreased as the precursor concentration decreased and the spray pyrolysis temperature increased. Sinterability tests conducted at 1100°C for 1 h showed that the smaller and denser the particles were, the higher the relative densities were of sintered hydroxyapatite disks formed from these particles. The practical implication of these results is that highly sinterable small and dense hydroxyapatite particles can be synthesized by means of spray pyrolysis using a low-concentration precursor solution and a high pyrolysis temperature under a fixed carrier gas flow rate. PMID:25891158

  16. Formation of CuAlO2 Film by Ultrasonic Spray Pyrolysis

    International Nuclear Information System (INIS)

    Smooth, crack free and homogenous CuAlO2 film was produced by chemical solution deposition process via spray pyrolysis technique on a cleaned Si substrate. The precursor solution used was comprised of a mixture of 45.87 mmol Cu(NO3)2.3H2O and 90 mmol Al(NO3)3.9H2O at ratio of Cu:Al = 1.2:1. The precursor solution was placed in a mist chamber and was atomized by a nebulizer to produce precursor mist. The precursor mist was then carried out by Ar gas and was sprayed onto a heated Si. Two main parameters were studied: the distance between the nozzle of the precursor mist chamber and the Si and the temperature of the Si substrate. It appears that from the XRD data, CuAlO2 can be detected for samples prepared by spraying the precursor mist at temperature of > 550 deg. C with distance between the nozzle and the substrate of 3cm. Reaction of the Cu and Al ions in the mist near the substrate may have promoted the crystallisation of CuAlO2.

  17. Fabrication of CIGS thin films by using spray pyrolysis and post-selenization

    International Nuclear Information System (INIS)

    We fabricated Cu(In1-xGax)Se2 (x: 0 ∼ 0.4) thin films by using ultrasonic spray pyrolysis and post-selenization. First, we made Cu(In1-xGax)S2 (x: 0 ∼ 0.4) films by ultrasonic spray pyrolysis under an air environment. Then, we converted as-sprayed Cu(In1-xGax)S2 (CIGS) films to Cu(In1-xGax)Se2 (CIGSe) films through post-selenization. For all Ga fractions, the sprayed CIGS films were well recrystallized into poly-crystalline CIGSe films with a dominant (112) texture, which was confirmed by X-ray diffraction, Raman spectroscopy and energy dispersive X-ray analyses. This result indicates that CIGSe films with any amount of Ga substitution can be made by converting sprayed CIGS to CIGSe with post-selenization.

  18. Morphological, structural and electrochemical properties of lithium iron phosphates synthesized by Spray Pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, L.S. [Universidad Carlos III de Madrid and IAAB, Avda. de la Universidad, 30, 28911 Leganes, Madrid (Spain); Meatza, I. de [Dpto. Energia, CIDETEC, Po Miramon 196, Parque Tecnologico de San Sebastian, 20009 Donostia-San Sebastian (Spain); Martin, M.I., E-mail: imartin@ietcc.csic.e [Universidad Carlos III de Madrid and IAAB, Avda. de la Universidad, 30, 28911 Leganes, Madrid (Spain); Bengoechea, M. [Dpto. Energia, CIDETEC, Po Miramon 196, Parque Tecnologico de San Sebastian, 20009 Donostia-San Sebastian (Spain); Cantero, I. [Dpto. I-D-i Nuevas Tecnologias, CEGASA, Artapadura, 11, 01013 Vitoria-Gasteiz (Spain); Rabanal, M.E., E-mail: mariaeugenia.rabanal@uc3m.e [Universidad Carlos III de Madrid and IAAB, Avda. de la Universidad, 30, 28911 Leganes, Madrid (Spain)

    2010-03-01

    In the field of materials for lithium ion batteries, the lithium iron phosphate LiFePO{sub 4} has been proven for use as a positive electrode due to its good resistance to thermal degradation and overcharge, safety and low cost. The use of nanostructured materials would improve its efficiency. This work shows the results of the synthesis of nanostructured materials with functional properties for lithium batteries through aerosol techniques. The Spray Pyrolysis method allows synthesizing nanostructured particles with spherical geometry, not agglomerates, with narrow distribution of particle size and homogeneous composition in respect to a precursor solution. Experimental techniques were focused on the morphological (SEM and TEM), structural (XRD and HRTEM-SAED), chemical (EDS) and electrochemical characterization.

  19. A Spray Pyrolysis Method to Grow Carbon Nanotubes on Carbon Fibres, Steel and Ceramic Bricks.

    Science.gov (United States)

    Vilatela, Juan J; Rabanal, M E; Cervantes-Sodi, Felipe; García-Ruiz, Máximo; Jiménez-Rodríguez, José A; Reiband, Gerd; Terrones, Mauricio

    2015-04-01

    We demonstrate a spray pyrolysis method to grow carbon nanotubes (CNTs) with high degree of crystallinity, aspect ratio and degree of alignment on a variety of different substrates, such as conventional steel, carbon fibres (CF) and ceramics. The process consists in the chemical vapour deposition of both a thin SiO2 layer and CNTs that subsequently grow on this thin layer. After CNT growth, increases in specific surface by factors of 1000 and 30 for the steel and CF samples, respectively, are observed. CNTs growth on ceramic surfaces results in a surface resistance of 37.5 Ohm/sq. When using conventional steel as a rector tube, we observed CNTs growth rates of 0.6 g/min. Details of nanotube morphology and the growth mechanism are discussed. Since the method discussed here is highly versatile, it opens up a wide variety of applications in which specific substrates could be used in combination with CNTs. PMID:26353505

  20. Spray pyrolysis deposited tin selenide thin films for thermoelectric applications

    International Nuclear Information System (INIS)

    Tin selenide thin films were prepared by spray pyrolysis technique using tin (II) chloride and selenourea as a precursor compounds using Se:Sn atomic ratio of 1:1 in the starting solution onto glass substrates. Deposition process was carried out in the substrate temperature range of 250 °C–400 °C using 1 ml/min flow rate. The films were investigated using X-ray diffraction, field emission scanning electron microscopy, Raman spectroscopy, optical absorption and thermoelectric studies. The X-ray diffraction patterns suggest that the major phase is hexagonal-SnSe2 was present when the deposition was carried out in 275–375 °C temperature range, while for the films deposited in the below and above to this range, Sn and Se precipitates into some impure and mixed phase. Raman scattering analysis allowed the assignment of peaks at ∼180 cm−1 to the hexagonal-SnSe2 phase. The optical absorption study shows that the direct band gap of the film decreases with increase in substrate temperature and increasing crystallite size. The thermo-electrical measurements have shown n-type conductivity in as deposited films and the magnitude of thermo EMF for films has been found to be increasing with increasing deposition temperature, except for 350 °C sample. 350 °C deposited samples shows enhance thermoelectric value as compared to other samples. Thermoelectric study reveal that although sample deposited between 275 °C and 375 °C are structurally same but 350 °C sample is thermoelectrically best. - Highlights: • Influence of substrate temperature on the deposition of SnSe has been shown. • Seebeck measurements at 275°C–375 °C confirms n-type conductivity. • Higher seebeck coefficient has been observed at 350 °C deposited film. • Decrease in band gap was observed on increasing Tsub and size of the crystallites

  1. Stoichiometry and superconductive properties of YBaCuO films deposited by spray pyrolysis

    International Nuclear Information System (INIS)

    The dependence of the stoichiometry and the superconducting characteristics of YBaCuO films deposited by spray pyrolysis on the spraying solution composition and the deposition conditions is reported. It has been found that a proper optimization of the starting materials concentration in the spraying solution results in superconducting films with zero resistance temperature of 91 K and a transition to superconducting state within a 3 K range. X-ray diffraction and resistance vs temperature measurements have been used to monitor the crystal composition and the conductive characteristics of the films as a function of the spraying solution composition and the deposition parameters

  2. Properties of CuInS2 thin films prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    CuInS2 thin films of about 1 μm are prepared by spray pyrolysis. The X-ray analysis shows that the film sprayed at 1:1:3 ratio in the spraying mixture present single phase CuInS2 with chalcopyrite structure, and oriented preferentially in the (112) direction. The optical band gap at room temperature is around 1.45 eV. The composition of the thin films can be controlled by varying the sulphur content in the spray solution as shown by electron probe micro-analysis. The electrical properties are studied by varying the Cu:In ratio. (orig.)

  3. Synthesis and characterization of nano-sized MgB2 powder by spray pyrolysis method

    International Nuclear Information System (INIS)

    The nano-sized MgB2 powder was prepared by spray pyrolysis method in order to improve its flux pinning properties by increasing the number of grain boundaries. MgB2 powder was synthesized using spray pyrolysis technique followed by a post-annealing process without excessive magnesium addition. The feed solution was prepared by dissolving the correct amounts of Boric acid and Magnesium acetate tetrahydrate into distillated water and ethanol solution and the overall concentration were fixed at 0.1 mol/L. During the decomposition, 96% Ar-4% H2 was used as carrier gas. The collected powders were characterized by X-ray diffraction, scanning electron microscopy, particle size analyzer, and physical property measurement system. The particles prepared by spray pyrolysis showed spherical morphology and uniform distribution with the average size of 1 μm. The onset of superconducting Tc for synthesized MgB2 powder was around 38 K

  4. An alternative fluorine precursor for the synthesis of SnO2:F by spray pyrolysis

    International Nuclear Information System (INIS)

    An alternative, non-toxic precursor was employed for the synthesis of SnO2:F transparent conducting oxide. The performance of benzenesulfonyl fluoride (BSF) as F source for spray pyrolysis was investigated. Its decomposition and the actual incorporation of fluorine in the tin oxide matrix were confirmed by X-ray photoelectron spectroscopy while its effect on the electrical properties was investigated by resistance and Hall measurements. Results were compared with respect to samples grown using a common fluorine source (NH4F), a commercial available sample and a sample grown by spray pyrolysis at an independent laboratory. We show that BSF leads to actively doped conductive SnO2 with good carrier mobility, though the fluorine incorporation rate and hence overall conductivity of the films is lower than for fluorine precursors commonly used in spray pyrolysis.

  5. Ceria Prepared by Flame Spray Pyrolysis as an Efficient Catalyst for Oxidation of Diesel Soot

    DEFF Research Database (Denmark)

    Christensen, Jakob Munkholt; Deiana, Davide; Grunwaldt, Jan-Dierk;

    2014-01-01

    Ceria has been prepared by flame spray pyrolysis and tested for activity in catalytic soot oxidation. In tight contact with soot the oxidation activity (measured in terms of the temperature of maximal oxidation rate, Tmax) of the flame made ceria is among the highest reported for CeO2. This can to...... a significant degree be ascribed to the large surface area achieved with the flame spray pyrolysis method. The importance of the inherent soot reactivity for the catalytic oxidation was studied using various soot samples, and the reactivity of the soot was found to have a significant impact, as the...

  6. Structural and optical characterization of nanostructured CdS thin films deposited by spray pyrolysis method

    International Nuclear Information System (INIS)

    Influence of solution pH on the structural and optical properties of CdS films deposited by conventional spray pyrolysis technique was studied. X-ray diffraction, atomic force microscopy, photoluminescence spectroscopy and spectroscopic ellipsometry methods were used for the characterization of films. The difference in the properties of the films was analyzed in terms of variation of grain sizes of the films. In this work there was an attempt of preparation of nanostructured CdS thin films by spray pyrolysis method was made. The preliminary results of structural and optical characterization of the films are given

  7. Spray pyrolysis deposited tin selenide thin films for thermoelectric applications

    Energy Technology Data Exchange (ETDEWEB)

    Anwar, Sharmistha; Gowthamaraju, S.; Mishra, B.K.; Singh, S.K.; Shahid, Anwar, E-mail: shahidanwr@gmail.com

    2015-03-01

    Tin selenide thin films were prepared by spray pyrolysis technique using tin (II) chloride and selenourea as a precursor compounds using Se:Sn atomic ratio of 1:1 in the starting solution onto glass substrates. Deposition process was carried out in the substrate temperature range of 250 °C–400 °C using 1 ml/min flow rate. The films were investigated using X-ray diffraction, field emission scanning electron microscopy, Raman spectroscopy, optical absorption and thermoelectric studies. The X-ray diffraction patterns suggest that the major phase is hexagonal-SnSe{sub 2} was present when the deposition was carried out in 275–375 °C temperature range, while for the films deposited in the below and above to this range, Sn and Se precipitates into some impure and mixed phase. Raman scattering analysis allowed the assignment of peaks at ∼180 cm{sup −1} to the hexagonal-SnSe{sub 2} phase. The optical absorption study shows that the direct band gap of the film decreases with increase in substrate temperature and increasing crystallite size. The thermo-electrical measurements have shown n-type conductivity in as deposited films and the magnitude of thermo EMF for films has been found to be increasing with increasing deposition temperature, except for 350 °C sample. 350 °C deposited samples shows enhance thermoelectric value as compared to other samples. Thermoelectric study reveal that although sample deposited between 275 °C and 375 °C are structurally same but 350 °C sample is thermoelectrically best. - Highlights: • Influence of substrate temperature on the deposition of SnSe has been shown. • Seebeck measurements at 275°C–375 °C confirms n-type conductivity. • Higher seebeck coefficient has been observed at 350 °C deposited film. • Decrease in band gap was observed on increasing Tsub and size of the crystallites.

  8. Luminescent characteristics of CaSO{sub 4}:Dy films obtained by spray pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Roman, J., E-mail: holand_jeos@hotmail.com [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Legaria-IPN, Av. Legaria 694, Col. Irrigacion, Mexico, D.F. 11500 (Mexico); Rivera, T.; Lozano, I.B. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Legaria-IPN, Av. Legaria 694, Col. Irrigacion, Mexico, D.F. 11500 (Mexico); Sosa, R. [Universidad Autonoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco186, Col. Vicentina, Mexico, D.F., 09340 (Mexico); Alarcon, G. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Legaria-IPN, Av. Legaria 694, Col. Irrigacion, Mexico, D.F. 11500 (Mexico)

    2012-07-15

    The present paper reports the experimental results of dysprosium doped calcium sulphate (CaSO{sub 4}:Dy) films deposited by spray pyrolysis method. CaSO{sub 4}:Dy films were deposited on three different surfaces: glass, aluminum and quartz substrates at temperatures in the range from 450 to 600 Degree-Sign C. Structural and morphological characteristics of CaSO{sub 4}:Dy films were observed. Thermoluminescent characteristics of films were determined by irradiating ultraviolet energy region. Thermoluminescent glow curve of CaSO{sub 4}:Dy films with glass and aluminum substrates showed a peak under environmental irradiation. Both TL response glow shape and intensity of CaSO{sub 4}:Dy films UV irradiated as a function of substrates were studied. - Highlights: Black-Right-Pointing-Pointer We carried out the preparation of calcium sulfate films doped with dysprosium (CaSO{sub 4}:Dy) by spray paralysis method. Black-Right-Pointing-Pointer SEM and EDS techniques were applied to study the surface topography and chemical composition of the CaSO{sub 4}:Dy films. Black-Right-Pointing-Pointer Thermoluminescent characteristics of films were determined by irradiating ultraviolet energy region. Black-Right-Pointing-Pointer The thermoluminescent response of CaSO{sub 4}:Dy films as a function of substrate was analyzed.

  9. Luminescent characteristics of CaSO4:Dy films obtained by spray pyrolysis method

    International Nuclear Information System (INIS)

    The present paper reports the experimental results of dysprosium doped calcium sulphate (CaSO4:Dy) films deposited by spray pyrolysis method. CaSO4:Dy films were deposited on three different surfaces: glass, aluminum and quartz substrates at temperatures in the range from 450 to 600 °C. Structural and morphological characteristics of CaSO4:Dy films were observed. Thermoluminescent characteristics of films were determined by irradiating ultraviolet energy region. Thermoluminescent glow curve of CaSO4:Dy films with glass and aluminum substrates showed a peak under environmental irradiation. Both TL response glow shape and intensity of CaSO4:Dy films UV irradiated as a function of substrates were studied. - Highlights: ► We carried out the preparation of calcium sulfate films doped with dysprosium (CaSO4:Dy) by spray paralysis method. ► SEM and EDS techniques were applied to study the surface topography and chemical composition of the CaSO4:Dy films. ► Thermoluminescent characteristics of films were determined by irradiating ultraviolet energy region. ► The thermoluminescent response of CaSO4:Dy films as a function of substrate was analyzed.

  10. Structure of alumina supported vanadia catalysts for oxidative dehydrogenation of propane prepared by flame spray pyrolysis

    DEFF Research Database (Denmark)

    Høj, Martin; Jensen, Anker Degn; Grunwaldt, Jan-Dierk

    2013-01-01

    A series of five vanadia on alumina catalysts for oxidative dehydrogenation of propane to propene were synthesized by flame spray pyrolysis (FSP) using vanadium(III)acetylacetonate and aluminium(III)acetylacetonate dissolved in toluene as precursors. The vanadium loading was 2, 3, 5, 7.5 and 10wt...

  11. Continuous synthesis of graphene sheets by spray pyrolysis and their use as catalysts for fuel cells.

    Science.gov (United States)

    Zou, Biao; Wang, Xiao Xia; Huang, Xin Xin; Wang, Jian Nong

    2015-01-14

    Graphene sheets (GNS) were synthesized continuously by spray pyrolysis of iron carbonyl and pyridine. The Pt catalyst supported on GNS exhibited excellent durability for oxygen reduction reaction (ORR). The GNS, when used as a metal-free catalyst for ORR, showed performance even better than the commercial Pt/C catalyst. PMID:25421428

  12. Assisted spray pyrolysis production and characterisation of ZnO nanoparticles with narrow size distribution

    International Nuclear Information System (INIS)

    Nano-sized ZnO particles with a narrow size distribution and high crystallinity were prepared from aqueous solutions with high concentrations of Zn2+ containing salts and citric acid in a conventional spray pyrolysis setup. Structure, morphology and size of the produced material were compared to ZnO material produced by simple spray pyrolysis of zinc nitrates in the same experimental setup. Using transmission electron microscopy and electron tomography it has been shown that citric acid-assisted spray pyrolysed material is made up of micron sized secondary particles comprising a shell of lightly agglomerated, monocrystalline primary ZnO nanoparticles with sizes in the 20-30 nm range, separable by a simple ultrasonic treatment step.

  13. Properties Study of ZnS Thin Films Prepared by Spray Pyrolysis Method

    Directory of Open Access Journals (Sweden)

    A. Djelloul

    2015-12-01

    Full Text Available Zinc sulfide (ZnS is important II-VI semiconductors material for the development of various modern technologies and photovoltaic applications. ZnS thin film was prepared by using chemical spray pyrolysis technique. The starting solution is a mixture of 0.1 M zinc chloride as source of Zn and 0.05 M thiourea as source of S. The glass substrate temperature was varied in the range of 300 °C-400 °C to investigate the influence of substrate temperature on the structure, chemical composition, morphological and optical properties of ZnS films. The DRX analyses indicated that ZnS films have polycrystalline cubic structure with (111 preferential orientation and grain size varied from 25 to 60 nm, increasing with substrate temperature. The optical properties of these films have been studied in the wavelength range 300-2500 nm using UV-VIS spectro-photometer. The ZnS films has a band gap of 3.89 eV-3.96 eV.

  14. Synthesis of LiVO{sub 3} thin films by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Bouzidi, A., E-mail: bouzidi_attou@yahoo.f [Laboratoire d' Elaboration et de Caracterisations des Materiaux, Departement d' Electronique, Universite Djillali Liabes, BP89, Sidi Bel Abbes 22000 (Algeria); Benramdane, N.; Medles, M.; Khadraoui, M. [Laboratoire d' Elaboration et de Caracterisations des Materiaux, Departement d' Electronique, Universite Djillali Liabes, BP89, Sidi Bel Abbes 22000 (Algeria); Bresson, S. [Laboratoire de Biochimie, INSERM, ERI 12, Centre Hospitalier Universitaire, Universite de Picardie Jules Verne, Place Victor Pauchet, F-80000 Amiens (France); Mathieu, C.; Desfeux, R. [Universite d' Artois, Faculte Jean Perrin, Rue Jean Souvraz, SP18, 62307 Lens (France); Marssi, M. El. [Laboratoire de Physique de la Matiere Condensee, Universite de Picardie Jules Verne, 33 rue St. Leu, 80039 Amiens (France)

    2010-08-06

    Lithium metavanadate thin films were successfully deposited on glass substrates by spray pyrolysis technique at substrate temperature of 250 {sup o}C. 0.2 M spraying solution was prepared by mixing appropriate volumes of LiCl and VCl{sub 3} solutions. Structural, vibrational and optical properties of deposited film are discussed. X-ray diffraction and micro-Raman spectroscopy have revealed that LiVO{sub 3} with monoclinic symmetry was obtained. Optical properties of thin film were studied from transmission measurement in the range UV-Visible.

  15. Synthesis and Characterization of LiNi_<0.5>Mn_<1.5.O_4 Particles by Internal Combustion Type Spray Pyrolysis and Spray Drying

    OpenAIRE

    MYOUJIN, Kenichi; Kojima, Masayuki; Ogihara, Takashi; NAKANE, Koji; OGATA, Nobuo

    2008-01-01

    Spherical LiNi_Mn_O_4 precursor powders were synthesized different heating method by internal combustion type spray pyrolysis apparatus using gas burner. After calcinations of as-prepared powders contained Ni at different temperatures from 800 to 1200 ℃ in air for 10h, LiNi_Mn_O_4 powders were obtained. As-prepared particles have a porous microstructure with an average diameter of about 5 μm (spray pyrolysis) and 2 μm (spray drying) with narrow size distribution. The powder production capacit...

  16. Use of co-spray pyrolysis for synthesizing nitrogen-doped TiO2 films

    Indian Academy of Sciences (India)

    Nho Pham Van; Pham Hoang Ngan

    2013-10-01

    Nitrogen-doped nanocrystalline TiO2 is well known as the most promising photocatalyst. Despite many years after discovery, seeking of efficient method to prepare TiO2 doped with nitrogen still attracts a lot of attention. In this paper, we present the result of using co-spray pyrolysis to synthesize nitrogen-doped TiO2 films from TiCl4 and NH4NO3. The grown films were subjected to XRD, SEM, photocatalysis, absorption spectra and visible-light photovoltaic investigations. All the deposited films were of nanosized polycrystal, high crystallinity, pure anatase and porosity. Specific characteristics involved nitrogen doping such as enhanced photocatalytic activity, bandgap narrowing, visible light responsibility and typical correlation of the photoactivity with nitrogen concentration were all exhibited. Obtained results proved that high photoactive nitrogen-doped TiO2 films can be synthesized by co-spray pyrolysis.

  17. Magnetoelectric coupling of spray pyrolysis deposited multiferroic BiFeO3 films

    International Nuclear Information System (INIS)

    Magnetoelectric effect has been studied in films of BiFeO3 with particle sizes in the range, 12 to 92 nm deposited by spray pyrolysis method. The field emission scanning electron microscopy images show that the films were uniform, dense and of near spherically shaped nano-particles. The ferroelectric loops were studied in the presence of magnetic field and about 30% increase in the remanent polarization was obtained. The enhanced polarization was observed above some critical value of the applied field which is attributed to the suppression of cycloidal spin structure. A large coupling between ferromagnetic and ferroelectric order parameters has been found at room temperature. It has been attributed to the large ferroelastic domains and suppression of the cycloid spin structure. - Highlights: ► BiFeO3 films deposited by spray pyrolysis method at low temperature ► Improved ferroelectric and ferromagnetic properties were obtained ► A strong magnetoelectric coupling was observed

  18. Hybrid solar cells using CdS thin films deposited via spray pyrolysis technique

    International Nuclear Information System (INIS)

    The paper presents the photovoltaic performance of hybrid solar cells comprising of thin films of cadmium sulphide and poly(3-hexyl)thiophene. Cadmium sulphide thin films were deposited using spray pyrolysis technique. Current-voltage characterizations were performed for cadmium sulphide/poly(3-hexyl)thiophene heterojunctions in dark and under illumination (100 mWcm−2). The best device yields a short circuit current density of 1.54 mA/cm2, an open circuit voltage of 343 mV, and a power conversion efficiency of 0.15%. - Highlights: • Hybrid solar cells were fabricated using CdS and poly(3-hexyl)thiophene. • CdS thin films were grown by spray pyrolysis technique. • The best cell performance was achieved for the 100 nm thick CdS films. • The highest short circuit current was measured as 1.54 mAcm−2 for the best cell

  19. Synthesis and characterization of spherical magnesium di-boride nano-powders obtained by spray pyrolysis

    International Nuclear Information System (INIS)

    Nano-sized spherical MgB2 powders were prepared by spray pyrolysis, starting from an aqueous solution which contains Mg and B ions. The influence of solution concentration, furnace temperature and mass flow of carrier gas on microstructure and average particle size were investigated. The powders were synthesized without further heat treatment. For adequate preparation conditions, it has mostly spherical, solid and narrow particle size distribution. Average particle size (X50) distribution was between 100 and 400 nm

  20. Growth Temperature Effect on Carbon Nano tubes Formation by Spray Pyrolysis Method

    International Nuclear Information System (INIS)

    Carbon nano tubes has been produced by using spray pyrolysis method with no carrier gas. Carbon nano tubes were formulated from a mixture a ferrocene and benzene with certain ratio and then the mixture were injected by the sprayer into the furnace. Growth temperature was optimized in the range of 650 until 850 oC to get the high quality of carbon nano tubes. These were characterized by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX). (author)

  1. Eu-doped barium strontium silicate phosphor particles prepared from spray solution containing NH4Cl flux by spray pyrolysis

    International Nuclear Information System (INIS)

    Eu-doped barium strontium silicate phosphor particles with high photoluminescence intensity under long wavelength ultraviolet were prepared from the spray solution containing NH4Cl flux by spray pyrolysis. It was found that the addition of NH4Cl to the spray solution makes it possible to greatly improve the photoluminescence intensity of Ba1.488Sr0.5SiO4:Eu0.012 phosphor particles under long wavelength ultraviolet of 410 nm. The highest photoluminescence intensity, which was achieved when the NH4Cl content was 5 wt.%, was about 150% of Ba1.488Sr0.5SiO4:Eu0.012 particles prepared from the spray solution without flux material at the post-treatment temperature of 1050 deg. C. The particle size of Ba1.488Sr0.5SiO4:Eu0.012 phosphor particles were enlarged by using the NH4Cl flux in the spray solution because of the large grain growth which was identified from the sharpening of the XRD peaks. Adding the NH4Cl flux into the spray solution was found to lower the optimal post-treatment temperature at which the Ba1.488Sr0.5SiO4:Eu0.012 phosphor particles are fully crystallized and have the maximum photoluminescence intensity. The phosphor particles prepared from spray solution containing 5 wt.% NH4Cl flux had the maximum photoluminescence intensity at post-treatment temperature of 1100 deg. C

  2. Cu2ZnSnS4 thin films deposition by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Highlights: ► CZTS thin films were deposited by ultrasonic spray pyrolysis technique. ► The deposition rate shows two thermal activation energies. ► Films have a kesterite hexagonal structure with (1 1 2) preferential orientation. ► Stannate ZnSnO3 is present as a secondary phase. - Abstract: Cu2ZnSnS4 (CZTS) thin films were deposited by ultrasonic spray pyrolysis technique. The substrate temperature was varied from 280 to 360 °C in order to investigate its influence on CZTS films properties. The deposition rate shows two activation energies 0.16 and 0.53 eV, respectively at low and high substrate temperatures. This indicates that CZTS deposition by spray pyrolysis passes by two different processes with increasing temperature substrate. The temperature 320 °C corresponds to the transition between these two processes. The X rays diffraction (XRD) analysis indicated that the deposited films have a kesterite hexagonal structure with (1 1 2) preferential orientation and a crystalline size, ranged from 30 to 52 nm with increasing substrate temperature. Stannate ZnSnO3 is present as a secondary phase. The presence of this secondary phase causes films optical band broadening. Broad emissions at around 1.27 eV was observed in the photoluminescence spectrum measured at 77 K, it is accompanied with a small peak located at 1.75 eV due the presence of zinc stannate phase ZnSnO3.

  3. Properties of Ni–Zn ferrite thin films deposited using spray pyrolysis

    International Nuclear Information System (INIS)

    Nanocrystalline, homogeneous spinel Ni1−xZnxFe2O4 thin films were deposited on glass substrates by using spray pyrolysis of metal nitrate aqueous solutions. The thickness of deposited films was below 500 nm, but crystallite size was under 30 nm. It has been shown that the DC resistivity, dielectric loss and optical band gap of deposited films are influenced by the zinc content. High DC resistivity and low dielectric losses of thin Ni1−xZnxFe2O4 films are explained by mixed n-p conductivity and nanograin structure of spray pyrolysis deposited coatings which are changing with the ratio of Ni/Zn. - Highlights: ► Nanostructured Ni–Zn ferrite thin films were deposited by spray pyrolysis. ► X-Ray diffraction reveals a single-phase spinel structure for the obtained films. ► The thickness of deposited films was below 500 nm. ► Ni1−xZnxFe2O4 films characterized with high resistivity and low dielectric losses.

  4. An experimental and modeling investigation of particle production by spray pyrolysis using a laminar flow aerosol reactor

    International Nuclear Information System (INIS)

    The influence of operating parameters on the morphology of particles prepared by spray pyrolysis was investigated using a temperature-graded laminar flow aerosol reactor. Experimentally, zirconia particles were prepared by spray pyrolysis using an aqueous solution of zirconyl hydroxide chloride. Hollow particles were formed if the reactor temperature was high, the temperature gradient was too large, the flow rate of carrier gas was high, and the initial solute concentration was low. A numerical simulation of the pyrolysis process was developed using a combination of two previous models. The simulation results compared well with the experimental results. (c) 2000 Materials Research Society

  5. High-rate production of functional nanostructured films and devices by coupling flame spray pyrolysis with supersonic expansion

    International Nuclear Information System (INIS)

    The fabrication of functional thin films and devices by direct deposition of nanoparticles from the gas phase is a promising approach enabling, for instance, the integration of complex analytical and sensing capabilities on microfabricated platforms. Aerosol-based techniques ensure large-scale nanoparticle production and they are potentially suited for this goal. However, they are not adequate in terms of fine control over the lateral resolution of the coatings, mild processing conditions (avoiding high temperature and aggressive chemicals), low contamination and compatibility with microfabrication processes. Here we report the high-rate and efficient production of functional nanostructured films by nanoparticle assembling obtained by the combination of flame spray pyrolysis and supersonic expansion. Our approach merges the advantages of flame spray pyrolysis for bulk nanopowders such as process stability and wide material library availability with those of supersonic cluster beam deposition in terms of lateral resolution and of direct integration of nanomaterials on devices. We efficiently produced nanostructured films and devices (such as gas sensors) using metal oxide, pure noble metal and oxide-supported noble metal nanoparticles. (paper)

  6. The characteristics of nano-sized Gd-doped CeO2 particles prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Gd-doped ceria particles with nanometer size were prepared by spray pyrolysis from spray solution containing ethylene glycol. The effect of ethylene glycol and gadolinium dopant on the morphology of the ceria particles prepared by spray pyrolysis was investigated. The Gd-doped ceria particles prepared from pure aqueous solution had submicron size, spherical shape and dense structure after post-treatment. The Gd-doped ceria particles prepared from solution containing ethylene glycol had loosely aggregated structure of the primary particles with nanometer size after post-treatment at 900 and 1050 deg. C. The Gd-doped ceria particles had more loosely aggregated and regular morphology than the pure ceria particles at the post-treatment temperature of 900 deg. C. The gadolinium component used as dopant suppressed grain growth in ceria particles prepared by spray pyrolysis. Nanometer size Gd-doped ceria particles were prepared by a ball milling process of the particles obtained by spray pyrolysis. The mean size of the Gd-doped ceria particles was 46 nm after a post-treatment at 1050 deg. C. The ionic conductivity of the Gd-doped ceria particles prepared by spray pyrolysis was compared with that of the commercial yttria-stabilized zirconia (YSZ)

  7. Yttrium doped BaCeO3 thin films by spray pyrolysis technique for application in solid oxide fuel cell

    International Nuclear Information System (INIS)

    Highlights: • BCY20 thin electrolyte was deposited by economical spray pyrolysis technique. • Solution concentration and annealing temperature affects structure and morphology. • Excellent agreement with XRD data of lattice parameter. • The dc conductivity in argon at 600 °C was 4.25 × 10−3 S cm−1. -- Abstract: Yttrium doped barium cerate (BCY) a solid state ion conductor which exhibits proton conductivity under proper atmospheric conditions, is used as an electrolyte in a solid oxide fuel cell (SOFCs). In present work, nanocrystalline BaCe0.8Y0.2O2.9 (BCY20) thin films were successfully deposited onto alumina substrates by simple and economical spray pyrolysis technique (SPT) at 250 °C. The effect of solution concentration and annealing on physico-chemical properties of BCY20 thin film has been studied. The X-ray diffraction (XRD) studies of spray pyrolysed BCY20 films revealed polycrystalline (crystallite size 35 nm) orthorhombic structure with lattice parameters a = 8.77 Å, b = 6.234 Å and c = 6.223 Å. The scanning electron micrographs showed dense morphology which is very useful for electrolyte. The stoichiometry was confirmed by elemental analysis and the estimated atomic ratio was in good agreement with that of the precursor solution ratio. The most intense band at 353.26 cm−1 observed in room temperature Raman spectrum of BCY20 film was due to vibrational mode of barium cerate. The FTIR spectra with heat treatment shows no carbon based vibration bonds, revealing absence of carbon based surface impurities in the sample. The dc conductivities measured in air and argon atmospheres at 600 °C were 1.7 × 10−3 and 4.25 × 10−3 S cm−1, respectively

  8. Nano-sized Y2O3:Eu phosphor particles prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Y2O3:Eu phosphor particles with nano-sized and non-aggregation characteristics were prepared by spray pyrolysis using spraying solution containing polymeric precursors and Li2CO3 flux material. The post-treated phosphor particles with fine size and high brightness were ball milled to reduce the aggregation degree of the nano-sized Y2O3:Eu phosphor particles. The mean particle size, morphology, and brightness of Y2O3:Eu phosphor particles were strongly affected by contents of the additives and post-treatment temperature. The Y2O3:Eu phosphor particles prepared from the solution containing 0.3 M citric acid, 0.3 M ethylene glycol and 5 wt.% Li2CO3 had fine size and good morphology after post-treatment. The Y2O3:Eu phosphor particles post-treated at 1000 deg. C for 3 h had the mean size of 300 nm. Nano-sized Y2O3:Eu phosphor particles prepared by spray pyrolysis had similar photoluminescence intensity to the micron-sized Y2O3:Eu commercial product prepared by solid state reaction method. The Y2O3:Eu phosphor particles had aggregation-free and regular morphology characteristics even after 30 min ball milling process

  9. Physical properties of Ga-doped ZnO thin films by spray pyrolysis

    International Nuclear Information System (INIS)

    Research highlights: In this work, we report the structural, optical and electrical properties of the transparent conducting GZO thin films prepared by spray pyrolysis method. We sought optimum deposition conditions yielding GZO films with desired physical properties, specifically good crystalline quality microstructure, low resistivity and high transparency. The electrical conductivity and mobilities of GZO thin films are very good as compared with previous reported spray pyrolysed films. - Abstract: Gallium doped zinc oxide (GZO) thin films were prepared using the simple, flexible and cost-effective spray pyrolysis technique. The physical properties of the films were studied as a function of increasing gallium dopant concentration from 1 to 9 at.%. The films were characterized by various methods to understand their structural, morphological, optical and electrical properties. The X-ray diffraction analysis revealed that the films were polycrystalline in nature having a hexagonal wurtzite type crystal structure with a preferred grain orientation in the (0 0 2) direction. Scanning electron microscopy (SEM) measurements reveal that the surface morphology of the films changes continuously with a decrease in the grain size due to Ga doping. All the films showed nearly 90% of transparency in the entire visible region. A blue shift of the optical band gap was observed with an increase in Ga doping. Room temperature photoluminescence (PL) measurement of the deposited films indicates incorporation of Ga in ZnO lattice. At 3 at.% Ga doping, the film has lowest resistivity of 6.8 x 10-3 cm while the carrier concentration is highest.

  10. Ultrasonic spray pyrolysis deposition of SnSe and SnSe2 using a single spray solution

    Institute of Scientific and Technical Information of China (English)

    Jorge Sergio Narro-Rios; Manoj Ramachandran; Dalia Martínez-Escobar; Aarón Sánchez-Juárez

    2013-01-01

    Thin films of SnSe and SnSe2 have been deposited using the ultrasonic spray pyrolysis (USP) technique.To the best of our knowledge this is the first report of the deposition of SnSe and SnSe2 thin films using a single spray solution.The use of a single spray solution for obtaining both a p-type material,SnSe,and an n-type material,SnSe2,simplifies the deposition technique.The SnSe2 thin films have a bandgap of 1.1 eV and the SnSe thin films have a band gap of 0.9 eV.The Hall measurements were used to determine the resistivity of the thin films.The SnSe2 thin films show a resistivity of 36.73 Ω·cm and n-type conductivity while the SnSe thin films show a resistivity of 180 Ω·cm and p-type conductivity.

  11. Ultrasonic spray pyrolysis deposition of SnSe and SnSe2 using a single spray solution

    International Nuclear Information System (INIS)

    Thin films of SnSe and SnSe2 have been deposited using the ultrasonic spray pyrolysis (USP) technique. To the best of our knowledge this is the first report of the deposition of SnSe and SnSe2 thin films using a single spray solution. The use of a single spray solution for obtaining both a p-type material, SnSe, and an n-type material, SnSe2, simplifies the deposition technique. The SnSe2 thin films have a bandgap of 1.1 eV and the SnSe thin films have a band gap of 0.9 eV. The Hall measurements were used to determine the resistivity of the thin films. The SnSe2 thin films show a resistivity of 36.73 Ω·cm and n-type conductivity while the SnSe thin films show a resistivity of 180 Ω·cm and p-type conductivity. (semiconductor materials)

  12. Single crystal ZnO:Al nanoparticles directly synthesized using low-pressure spray pyrolysis

    International Nuclear Information System (INIS)

    Aluminum-doped zinc oxide (AZO) nanoparticles powder were prepared using low-pressure spray pyrolysis (LPSP). AZO nanoparticles sized 16 and 20 nm with nearly spherical shapes and a crystal size of 11 and 15 nm were yielded using zinc acetate precursor at a low-pressure of 8.0 kPa with a pyrolysis temperature of 800 and 1000 deg. C. The thin films were deposited using a dip-coating method derived from the as-prepared AZO nanoparticles. The thin films that were heated for 1.5 h showed a transmittance higher than 97% in the wavelength range of 400-800 nm and a resistivity of 4.0 x 103 ohm cm with a film thickness of 250 nm. The high crystallinity and high transmittance of AZO nanoparticles that are directly synthesized using the LPSP process have potential for applications as transparent conducting material

  13. Gas sensing properties of nanostructured MoO{sub 3} thin films prepared by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, H.M.; Torres, J. [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica, Universidad Nacional de Colombia, Bogota (Colombia); Rodriguez-Garcia, M.E. [Departamento de Nanotecnologia, Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, Queretaro, Qro. (Mexico); Lopez Carreno, L.D., E-mail: ldlopezca@unal.edu.co [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica, Universidad Nacional de Colombia, Bogota (Colombia)

    2012-08-15

    Thin films of molybdenum trioxide (MoO{sub 3}) were deposited on common glass using the chemical spray pyrolysis technique. A (NH{sub 4}){sub 6}Mo{sub 7}O{sub 24}4H{sub 2}0 solution 0.1 M was used as the precursor one. The influence of substrate temperature on the crystallographic structure, surface morphology and electrical behavior of MoO{sub 3} thin films was studied. MoO{sub 3} can exist in two crystalline forms, the thermodynamically stable orthorhombic {alpha}-MoO{sub 3} and the metastable monoclinic {beta}-MoO{sub 3} phase. XRD-spectra showed a growth of {alpha}-MoO{sub 3} phase percentage as substrate temperature increases from 420 K up to 670 K. Films deposited in the 500-600 K range have a clearly porous surface structure of nanometer order as can be seen in SEM images. Changes up to six magnitude orders were observed in MoO{sub 3} thin films electrical resistance when films temperature varied from 100 K up to 500 K. The sensing property of these MoO{sub 3} films was also studied. The sensitivity was investigated in the temperature range 160 and 360 K for H{sub 2}O and CO gases, respectively. Both of them are of reducing nature. In all studied cases sensitivity decreases slowly as film temperature is raised. At room temperature the sensitivity changes from 12 up to 75% depending on substrate temperature. The sensitivity for CO gas was found to be lower than that of H{sub 2}O.

  14. Ultrasonic spray pyrolysis of surface modified TiO{sub 2} nanoparticles with dopamine

    Energy Technology Data Exchange (ETDEWEB)

    Dugandžić, Ivan M. [Institute of Technical Sciences of SASA, Knez Mihailova 35/IV, 11000 Belgrade (Serbia); Jovanović, Dragana J. [Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Mančić, Lidija T.; Milošević, Olivera B. [Institute of Technical Sciences of SASA, Knez Mihailova 35/IV, 11000 Belgrade (Serbia); Ahrenkiel, Scott P. [South Dakota School of Mines and Technology, 501 E. Saint Joseph St., Rapid City, SD 57701 (United States); Šaponjić, Zoran V. [Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Nedeljković, Jovan M., E-mail: jovned@vinca.rs [Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia)

    2013-12-16

    Spherical, submicronic TiO{sub 2} powder particles were prepared in the low temperature process of ultrasonic spray pyrolysis (150 °C) by using as a precursor aqueous colloidal solutions consisting of surface modified 45 Å TiO{sub 2} nanoparticles with dopamine. Detailed structural and morphological characterization of colored submicronic TiO{sub 2} spheres was performed by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), laser particle size analysis and FTIR techniques. Also, optical characterization of both dopamine-modified TiO{sub 2} precursor nanoparticles and submicronic TiO{sub 2} powder particles was performed using absorption and diffuse reflectance spectroscopy, respectively. A significant decrease of the effective band gap (1.9 eV) in dopamine-modified TiO{sub 2} nanoparticles compared to the band gap of bulk material (3.2 eV) was preserved after formation of submicronic TiO{sub 2} powder particles in the process of ultrasonic spray pyrolysis under mild experimental conditions. Due to the nanostructured nature, surface-modified assemblage of TiO{sub 2} nanoparticles preserved unique ability to absorb light through charge transfer complex by photoexcitation of the ligand-to-TiO{sub 2} band, conventionally associated with extremely small TiO{sub 2} nanoparticles (d < 20 nm) whose surface Ti atoms, owing to the large curvature, have penta-coordinate geometry. - Highlights: • The surface-modified TiO{sub 2} nanoparticles with dopamine were used as a precursor. • Colored submicronic TiO{sub 2} particles were obtained after ultrasonic spray pyrolysis. • CT complex was formed between electron donating ligands and surface Ti atoms. • The effective band-gap of surface modified TiO{sub 2} powders decreases to 1.3 eV.

  15. Ultrasonic spray pyrolysis of surface modified TiO2 nanoparticles with dopamine

    International Nuclear Information System (INIS)

    Spherical, submicronic TiO2 powder particles were prepared in the low temperature process of ultrasonic spray pyrolysis (150 °C) by using as a precursor aqueous colloidal solutions consisting of surface modified 45 Å TiO2 nanoparticles with dopamine. Detailed structural and morphological characterization of colored submicronic TiO2 spheres was performed by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), laser particle size analysis and FTIR techniques. Also, optical characterization of both dopamine-modified TiO2 precursor nanoparticles and submicronic TiO2 powder particles was performed using absorption and diffuse reflectance spectroscopy, respectively. A significant decrease of the effective band gap (1.9 eV) in dopamine-modified TiO2 nanoparticles compared to the band gap of bulk material (3.2 eV) was preserved after formation of submicronic TiO2 powder particles in the process of ultrasonic spray pyrolysis under mild experimental conditions. Due to the nanostructured nature, surface-modified assemblage of TiO2 nanoparticles preserved unique ability to absorb light through charge transfer complex by photoexcitation of the ligand-to-TiO2 band, conventionally associated with extremely small TiO2 nanoparticles (d 2 nanoparticles with dopamine were used as a precursor. • Colored submicronic TiO2 particles were obtained after ultrasonic spray pyrolysis. • CT complex was formed between electron donating ligands and surface Ti atoms. • The effective band-gap of surface modified TiO2 powders decreases to 1.3 eV

  16. Effect of film thickness on the transport properties of MgB2 synthesized by spray pyrolysis

    International Nuclear Information System (INIS)

    Research highlights: → Thickness of film cab be easily control by spray pyrolysis. → Critical current density of film is comparable to other film synthesized by different route. → Spray pyrolysis is a simple, economic viability technique to synthesis MgB2 film. - Abstract: Polycrystalline MgB2 films of different thickness have been prepared by employing spray pyrolysis technique on MgO (1 0 0) substrate. The MgB2 and other phases have been confirmed using X-ray diffraction technique and no trace of impurities phases have been found. The resistivity behavior shows that the superconducting transition temperature lies in the range of 37-39 K with narrow transition width. The transport critical current density vary with films thickness and achieved highest value ∼1.2 x 106 A/cm2 at 20 K for 2.0 μm thick film and its values increase as thickness increases.

  17. Study of ferroelectric properties of spray pyrolysis deposited cesium nitrate films

    Energy Technology Data Exchange (ETDEWEB)

    Nautiyal, Arvind, E-mail: nautyphysics@gmail.co [Ferroelectric Materials and Devices Research Laboratory, Department of Physics, Indian Institute of Technology Roorkee, Roorkee 247667 (Uttrakhand) (India); Sekhar, K.C. [Ferroelectric Materials and Devices Research Laboratory, Department of Physics, Indian Institute of Technology Roorkee, Roorkee 247667 (Uttrakhand) (India); Pathak, N.P. [Radio Frequency Integrated Circuits Research Laboratory, Department of Electronics and Computer Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 (Uttrakhand) (India); Nath, R., E-mail: rnathfph@iitr.ernet.i [Ferroelectric Materials and Devices Research Laboratory, Department of Physics, Indian Institute of Technology Roorkee, Roorkee 247667 (Uttrakhand) (India)

    2010-10-01

    Cesium nitrate (CsNO{sub 3}) films were prepared by ultrasonic spray pyrolysis technique at different substrate temperatures (T{sub s}) and their ferroelectric and switching properties were examined. The morphology of the deposited films was studied using FESEM. The ferroelectric properties were optimized based on remanent polarization as a function of substrate temperature. The switching response was studied using pulse width technique. The switching parameters such as effective dimensionality, switching time, and nucleation rate were extracted using finite grain model (FGM). The width of reading pulse shows significant effect on switching transients.

  18. Structural and optical characterization of InAs nanocrystals deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Mousa, A. M., E-mail: alzuhery51@yahoo.com; Mohammed, M. A.; Kadhim, R. [Department of Applied Sciences, University of Technology / Baghdad – Iraq (Iraq)

    2015-03-30

    4-5 nm size InAs nanocrystals were prepared by spray pyrolysis technique on glass substrates from alkaline solution containing InCl{sub 3} and As{sub 2}O. X-Ray diffraction and absorption spectra suggested that the deposition conditions (deposition time and temperature) had a profound influence on the structure and thickness of deposited layers. The optical absorption band edges shifted to lower energy when increasing the thickness with respect to the bulk material. The marked blue shift of the optical absorption edge indicated a strong quantum confinement effect in InAs films.

  19. Characterization of molybdenum-doped indium oxide thin films by spray pyrolysis technique

    Indian Academy of Sciences (India)

    S M Rozati; Z Bargebidi

    2013-08-01

    In this research, indium oxide nanostructure undoped and doped with Mo were prepared on glass substrates using spray pyrolysis technique. Various parameters such as dopant concentration and deposition temperatures were studied. Structural properties of these films were investigated by X-ray diffraction and scanning electron microscopy. Electrical and optical properties have been studied by Hall effect and UV–Visible spectrophotometer, respectively. The thickness of the films was determined by PUMA software. The variation of refractive index, extension coefficient and bandgap of these films also were investigated.

  20. Characterization of Transparent Conductive Thin Films of In2O3:Sn by Spray Pyrolysis Technique

    Directory of Open Access Journals (Sweden)

    Seyed M. Rozati

    2005-01-01

    Full Text Available Highly conductive transparent In2O3:Sn (ITO thin films were prepared onto glass substrate using the spray pyrolysis technique. It is observed that these films are polycrystalline with the preferred orientation of [400]. The extent of this orientation increases with substrate temperature. The results show that films with a sheet resistance as low as 35Ω/cm2 and with a transmittance as high as 90% in visible range can be achieved by controlling the substrate temperature and other preparation process.

  1. Evolution of Zinc Oxide Nanostructures Grown on Graphene by Ultrasonic Spray Pyrolysis and Its Statistical Growth Modelling

    OpenAIRE

    Ali, Amgad Ahmed; Hashim, Abdul Manaf

    2015-01-01

    The evolution of zinc oxide nanostructures grown on graphene by alcohol-assisted ultrasonic spray pyrolysis was investigated. The evolution of structures is strongly depended on pyrolysis parameters, i.e., precursor molarity, precursor flow rate, precursor injection/deposition time, and substrate temperature. Field-effect scanning electron microscope analysis, energy dispersive X-ray spectroscopy, X-ray diffraction, and transmission electron microscopy were used to investigate the properties ...

  2. Deposition of gold nanoparticle films using spray pyrolysis technique: Tunability of SPR band by electric field

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Neetesh; Komarala, Vamsi K.; Dutta, Viresh [Photovoltaic Laboratory, Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016 (India)

    2012-10-15

    Gold nanoparticle films are prepared using a simple inexpensive spray pyrolysis technique. X-ray as well as TEM diffraction patterns revealed pure cubic structure. The effect of gold nanoparticle concentration on surface plasmon resonance (SPR) band position and bandwidth are investigated for varying spray solution volume. The tunability of SPR band position and bandwidth using an electric field, by applying a voltage (up to 2000 V) to the nozzle, has been demonstrated. The reduced full width at half maximum and blue shift in the SPR band position are observed with {Delta}{lambda}{sub FW} {proportional_to} 55 nm and {Delta}{lambda}{sub P} {proportional_to} 40 nm for the applied voltage of 2 kV. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Synthesis of electrochromic tin oxide thin films with faster response by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Patil, P.S. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004 (India)], E-mail: psp_phy@unishivaji.ac.in; Sadale, S.B.; Mujawar, S.H.; Shinde, P.S.; Chigare, P.S. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004 (India)

    2007-08-15

    Tin oxide thin films have been synthesized via pyrolysis of tri-n-butyl tin acetate solution at various substrate temperatures. The effect of substrate temperature on electrochromic properties is studied by electrochemical cyclic voltammetry and chronoamperometry. The films deposited at various substrate temperatures (450, 475 and 500 deg. C) were polycrystalline and their preferred orientation changes from (1 1 0) to (2 0 0). Electrochromic performance indicated faster colour/bleach kinetics with appreciable reversibility in spray deposited SnO{sub 2} films. Maximum colouration efficiency and reversibility was attained for the sample deposited at 500 deg. C. All the spray deposited SnO{sub 2} thin films showed long term electrochemical stability in proton containing electrolyte.

  4. Synthesis of electrochromic tin oxide thin films with faster response by spray pyrolysis

    International Nuclear Information System (INIS)

    Tin oxide thin films have been synthesized via pyrolysis of tri-n-butyl tin acetate solution at various substrate temperatures. The effect of substrate temperature on electrochromic properties is studied by electrochemical cyclic voltammetry and chronoamperometry. The films deposited at various substrate temperatures (450, 475 and 500 deg. C) were polycrystalline and their preferred orientation changes from (1 1 0) to (2 0 0). Electrochromic performance indicated faster colour/bleach kinetics with appreciable reversibility in spray deposited SnO2 films. Maximum colouration efficiency and reversibility was attained for the sample deposited at 500 deg. C. All the spray deposited SnO2 thin films showed long term electrochemical stability in proton containing electrolyte

  5. Metal-semiconductor transition in undoped ZnO films deposited by spray pyrolysis

    International Nuclear Information System (INIS)

    ZnO films were deposited on glass substrate by using spray pyrolysis method. Films were deposited at different solution molarities 0.02 and 0.1 M. The films are highly transparent in the visible range of the electromagnetic spectrum with a transmission reaching up values to 90%. Band gaps were calculated as 3.24 and 3.28 eV with the help of transmission spectrums. When the solution molarity of the sprayed solution is increased from 0.02 to 0.1 M, carrier concentrations of the films increase from 1.6x1019 cm-3 to 5.1x1019 cm-3. Temperature-dependent conductivity measurements of these conducting and transparent films also showed, for the first time, a metal-semiconductor transition (MST). The deposited ZnO films show metallic conductivity above ∼420 K and semiconducting behavior at temperatures below it

  6. Electrical Characteristics of High-Performance ZnO Field-Effect Transistors Prepared by Ultrasonic Spray Pyrolysis Technique

    International Nuclear Information System (INIS)

    We have fabricated ZnO-based thin-film transistors (TFTs) by low-cost ultrasonic spray pyrolysis. The devices exhibit high saturation mobility of about 0.6 cm2/Vs and on-off current ratio of 105. The electrical characteristics of ZnO-based TFTs show that ultrasonic spray pyrolysis technique can be used as a promising approach to attain high-performance electronic devices. Furthermore, the deposition techniques make the operating process attractive for flexible electronics. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  7. Growth and properties of ZnO films on polymeric substrate by spray pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Kriisa, Merike; Kärber, Erki [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Krunks, Malle, E-mail: malle.krunks@ttu.ee [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Mikli, Valdek [Centre for Materials Research, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Unt, Tarmo; Kukk, Mart; Mere, Arvo [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia)

    2014-03-31

    The growth of ZnO layers deposited by spray pyrolysis on polymeric substrate was studied. Zinc acetate precursor solution was sprayed onto preheated polyimide (PI) and glass reference substrates at 380 °C. The structural, morphological, optical and electrical properties of the layers were measured by X-ray diffraction, scanning electron microscopy, optical spectroscopy and van der Pauw and Hall method. ZnO:In layers could be grown on PI when deposited onto undoped ZnO layer acting as a buffer layer on PI. Independent of the substrate type, the ZnO/ZnO:In bilayer showed a mixed morphology from smooth canvas-like surface to large scrolled belt grains dependent on buffer layer morphology. Due to the formation of scrolled belts, the ZnO:In layer shows no preferential orientation, yet the preferred orientation of the ZnO buffer crystallites is (100) plane parallel to the substrate. The bilayers deposited on PI exhibit high light scattering capability (haze factor of 85–95% in the spectral region of 350–1500 nm). The resistivity of the ZnO:In film in bilayer on PI is 4.4 × 10{sup −2} Ω cm mainly due to low carrier mobility of 1.5 cm{sup 2}/Vs, the carrier concentration is 10{sup 20} cm{sup −3}. - Highlights: • ZnO:In layers were grown on polyimide substrate by spray pyrolysis. • The buffer layer morphology is controlled by the layer thickness and spray rate. • ZnO/ZnO:In bilayer morphology is dependent on the surface of buffer layer. • Rough buffer layer leads to rough bilayer with scrolled belts (diameter of 2–6 μm). • Due to scrolled belts layers show no preferential growth yet highly scatter light.

  8. Growth and properties of ZnO films on polymeric substrate by spray pyrolysis method

    International Nuclear Information System (INIS)

    The growth of ZnO layers deposited by spray pyrolysis on polymeric substrate was studied. Zinc acetate precursor solution was sprayed onto preheated polyimide (PI) and glass reference substrates at 380 °C. The structural, morphological, optical and electrical properties of the layers were measured by X-ray diffraction, scanning electron microscopy, optical spectroscopy and van der Pauw and Hall method. ZnO:In layers could be grown on PI when deposited onto undoped ZnO layer acting as a buffer layer on PI. Independent of the substrate type, the ZnO/ZnO:In bilayer showed a mixed morphology from smooth canvas-like surface to large scrolled belt grains dependent on buffer layer morphology. Due to the formation of scrolled belts, the ZnO:In layer shows no preferential orientation, yet the preferred orientation of the ZnO buffer crystallites is (100) plane parallel to the substrate. The bilayers deposited on PI exhibit high light scattering capability (haze factor of 85–95% in the spectral region of 350–1500 nm). The resistivity of the ZnO:In film in bilayer on PI is 4.4 × 10−2 Ω cm mainly due to low carrier mobility of 1.5 cm2/Vs, the carrier concentration is 1020 cm−3. - Highlights: • ZnO:In layers were grown on polyimide substrate by spray pyrolysis. • The buffer layer morphology is controlled by the layer thickness and spray rate. • ZnO/ZnO:In bilayer morphology is dependent on the surface of buffer layer. • Rough buffer layer leads to rough bilayer with scrolled belts (diameter of 2–6 μm). • Due to scrolled belts layers show no preferential growth yet highly scatter light

  9. Decoration of crumpled rGO sheets with Ag nanoparticles by spray pyrolysis

    Science.gov (United States)

    Papailias, I.; Giannouri, M.; Trapalis, A.; Todorova, N.; Giannakopoulou, T.; Boukos, N.; Lekakou, C.

    2015-12-01

    In this work, crumpled reduced graphene oxide (rGO) nanostructures were produced using spray pyrolysis technique. Graphite oxide (GtO) prepared through a modified Hummers method was used as starting material. Water dispersions of graphene oxide (GO) were prepared and sprayed in a tube furnace at 300 °C, 500 °C and 700 °C using Argon (Ar) as carrier gas. Also, precursor dispersions with different AgNO3 concentrations were processed at the same conditions. During the treatment, the sprayed droplets underwent rapid heating and then gradual cooling until the exit of the oven, where crumpled rGO and Ag/rGO powders were collected. The prepared materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman and FT-IR spectroscopy. It was established that the crumpling of the nanosheets was slightly affected by the increase of the process temperature. Crumpled morphologies were obtained even at low temperature of 300 °C. In contrast, the degree of GO reduction was temperature dependent and increased with the increase of the temperature. The incorporation of Ag nanoparticles was evidenced by the XRD and TEM analysis with the size of the Ag nanoparticles to grow as the concentration of AgNO3 and/or the process temperature increased. SERS effect in the Raman spectra of the Ag/rGO materials was observed that reached a maximum at 500 °C. Spray pyrolysis was suggested as a simple, controllable and scalable route for the instantaneous crumpling, reduction and decoration of GO nanosheets with metal/metal oxide nanoparticles.

  10. Uniform nanoparticles by flame-assisted spray pyrolysis (FASP) of low cost precursors

    International Nuclear Information System (INIS)

    A new flame-assisted spray pyrolysis (FASP) reactor design is presented, which allows the use of inexpensive precursors and solvents (e.g., ethanol) for synthesis of nanoparticles (10–20 nm) with uniform characteristics. In this reactor design, a gas-assisted atomizer generates the precursor solution spray that is mixed and combusted with externally fed inexpensive fuel gases (acetylene or methane) at a defined height above the atomizing nozzle. The gaseous fuel feed can be varied to control the combustion enthalpy content of the flame and onset of particle formation. This way, the enthalpy density of the flame is decoupled from the precursor solution composition. Low enthalpy content precursor solutions are prone to synthesis of non-uniform particles (e.g., bimodal particle size distribution) by standard flame spray pyrolysis (FSP) processes. For example, metal nitrates in ethanol typically produce nanosized particles by gas-to-particle conversion along with larger particles by droplet-to-particle conversion. The present FASP design facilitates the use of such low enthalpy precursor solutions for synthesis of homogeneous nanopowders by increasing the combustion enthalpy density of the flame with low-cost, gaseous fuels. The effect of flame enthalpy density on product properties in the FASP configuration is explored by the example of Bi2O3 nanoparticles produced from bismuth nitrate in ethanol. Product powders were characterized by nitrogen adsorption, X-ray diffraction, X-ray disk centrifuge, and transmission electron microscopy. Homogeneous Bi2O3 nanopowders were produced both by increasing the gaseous fuel content and, most notably, by cutting the air entrainment prior to ignition of the spray.

  11. Deposition and characterization of graded Cu(In1-xGax)Se2 thin films by spray pyrolysis

    International Nuclear Information System (INIS)

    Cu(In1-xGax)Se2 (CIGS) thin films and their graded (x = 1 to 0) layer were grown on soda lime glass substrates using chemical spray pyrolysis (CSP) at different substrate temperatures (Ts). After optimization of Ts, depositions were carried out at different gallium composition (x) at optimized temperature of 350 °C. All the films deposited at Ts ≥ 350 °C were polycrystalline chalcopyrite structure, with a preferential orientation of (112), including the graded layer. With increase in x, lattice parameters a and c were observed to decrease. Line scan of the CIGS layer showed intersection of gallium and indium concentrations, revealing the graded nature of the film. Composition dependence of Raman peak for CuInSe2 (CIS) deposited by CSP was analyzed. Optical transmittance at a wavelength of 800 nm of the film with x = 0 (CIS) (30%) was found lower than that of the film grown with x = 0.82 (CIGS) (50%). Cusp-shape of the resistivity was observed with an increase of x leading to steep rise in resistivity of the films (1.61–71.68 Ω-cm) till x = 0.42 and then decreased to 4.78 Ω-cm at x = 0.82. Carrier concentrations of the films were evaluated in the order of 1016–1019 cm−3 with p-type conductivity. These results indicate that graded CIGS thin films with modulated gallium composition can be prepared by CSP. - Graphical abstract: Display Omitted - Highlights: • Optimization of the spray deposition system for device grade chalcopyrite CIGS films. • Optimized substrate temperature to obtain single-phase CIGS by spray deposition. • Detailed report on compositional dependence of CuInSe2 (CIS) thin films. • Systematic analysis of the influence of Ga in CIS by spray deposition. • Bowing parameter is extracted from the experiment values

  12. Studies on tin oxide films prepared by electron beam evaporation and spray pyrolysis methods

    Indian Academy of Sciences (India)

    K S Shamala; L C S Murthy; K Narasimha Rao

    2004-06-01

    Transparent conducting tin oxide thin films have been prepared by electron beam evaporation and spray pyrolysis methods. Structural, optical and electrical properties were studied under different preparation conditions like substrate temperature, solution flow rate and rate of deposition. Resistivity of undoped evaporated films varied from 2.65 × 10-2 -cm to 3.57 × 10-3 -cm in the temperature range 150–200°C. For undoped spray pyrolyzed films, the resistivity was observed to be in the range 1.2 × 10-1 to 1.69 × 10-2 -cm in the temperature range 250–370°C. Hall effect measurements indicated that the mobility as well as carrier concentration of evaporated films were greater than that of spray deposited films. The lowest resistivity for antimony doped tin oxide film was found to be 7.74 × 10-4 -cm, which was deposited at 350°C with 0.26 g of SbCl3 and 4 g of SnCl4 (SbCl3/SnCl4 = 0.065). Evaporated films were found to be amorphous in the temperature range up to 200°C, whereas spray pyrolyzed films prepared at substrate temperature of 300–370°C were polycrystalline. The morphology of tin oxide films was studied using SEM.

  13. Fabrication and Characterization of Nano Silver Powder Prepared by Spray Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qiaoxin; LIU Hao; WANG Xiaohui; SHI Xiaoliang; DUAN Xinglong

    2009-01-01

    Silver powder was fabricated by spray pyrolysis,using 2%-20% AgNO_3 solution,336-500 mL/h flux of AgNO_3 solution,0.28-0.32 MPa flux of carrier gas and in the 620-820℃tem-perature range.The effects of furnace set temperature,concentration of AgNO_3 aqueous solution,flux of AgNO_3 aqueous solution as well as carrier gas on the morphology and particle size distribution of silver powder,were investigated.The experimental results showed that with the high concentration of AgNO_3 aqueous solution,the average grain size of silver decreased with the increasing of furnace set temperature.But the gain size distribution was not homogenous,the discontinuous grain growth oc-curred.With the low concentration of AgNO_3 aqueous solution,the higher furnace set temperature made the nano sliver grains sintered together to grow.Nano silver powder about 100 nm was fabricated by spray pyrolysis,using 2wt% AgNO_3 solutions,336 mL/h flux of AgNO_3 aqueous solution,0.32 MPa flux of carrier gas at 720℃ furnace set temperature.

  14. Nanocrystalline CdS: In thin films prepared by the spray-pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Ikhmayies, Shadia J., E-mail: Shadia_Ikhmayies@yahoo.com [Al Isra University, Faculty of Information Technology, Department of Basic Sciences-Physics, Amman 16197 (Jordan); Juwhari, Hassan K.; Ahmad-Bitar, Riyad N. [University of Jordan, Faculty of Science, Physics Department, Amman 1192 (Jordan)

    2013-09-15

    Nanocrystalline CdS:In thin films were produced by the spray pyrolysis technique (SP) on glass substrates. The films were characterized by investigating their X-ray diffractograms (XRD), scanning electron microscope images (SEM), energy dispersive analysis by using X-rays (EDAX), transmittance curves and photoluminescence (PL) spectra. The absorbance was deduced from the transmittance measurements and then it was used to estimate the optical bandgap energies. This was done by plotting the first derivative of the absorbance against wavelength of the radiation, where the positions of the minima in this curve refer to the values of the optical bandgap energy. The size of the nanocrystallites was estimated from XRD diffractograms then from the hyperbolic band model using the estimated bandgap energies. Fine-structured PL spectra confirmed the nanocrystalline nature of the films. -- Highlights: • Nanocrystalline CdS:In thin films were produced by the spray pyrolysis technique. • XRD diffractograms and hyperbolic band model were used to find the grain size. • The distribution of the grain size is narrower for the thinner film. • Fine structure in the photoluminescence spectra is related to the nanoparticles.

  15. Nanostructure and magnetic properties of magnesium ferrite thin films deposited on glass substrate by spray pyrolysis

    International Nuclear Information System (INIS)

    The spinel MgFe2O4 thin films were prepared on the glass substrates at TS=400 °C by the spray pyrolysis deposition method. Structural and magnetic properties of the calcinated thin films at different temperatures were also investigated. By changing the calcination temperature from 400 to 600 °C, the crystallite size increased from 10 to 15 nm and the crystallinity of the films improved slightly. Thickness of the films calcinated at 400 and 600 °C were 0.648 and 1.473 μm respectively. However, the surface morphology of the films did not change considerably. Magnetic measurements, when the applied magnetic field was in parallel and perpendicular directions, showed the isotropic magnetic nature of the prepared films and their magnetic properties increased with the increment of calcination temperature. The Hc value of thin films calcinated at 400 °C was about 168 Oe. - Highlights: ► Thin films of MgFe2O4 are prepared via spray pyrolysis. ► All of the MgFe2O4 films have nanostructure and the special magnetic properties. ► The surface morphology of films in different calcination temperatures is similar. ► The Hc values of our films are independent of the applied field direction. ► The Ms values in the plan and perpendicular directions are not the same

  16. Spray combustion properties of fast pyrolysis bio-oil produced from rice husk

    International Nuclear Information System (INIS)

    The research presented here is focused primarily on spray combustion of pure fast pyrolysis bio-oil from rice husk. A combustion systems is developed to attain a possibility of firing of the bio-oil in a routine way. The start-up and shut down combustion procedures is established. The bio-oil is properly pretreated and spray combustion properties of pure fast pyrolysis bio-oil are studied. After 40 min combustion become steady and the temperature in the center of the combustion chamber is above 1400 deg. C. The CO concentration decreases with ER, and below a certain ER, the CO level exponentially increases. The measured NOx concentrations slightly increase at higher ER. Low values of SOx emissions are measured, and as expected these values are very low (2 concentration increases with ER. Bio-oil has the potential to replace diesel and gas for on-site power generation and heating, to be a fuel source for large-scale combustion systems such as furnaces, boilers and gas turbines.

  17. Antimony-Doped Tin Oxide Thin Films Grown by Home Made Spray Pyrolysis Technique

    Science.gov (United States)

    Yusuf, Gbadebo; Babatola, Babatunde Keji; Ishola, Abdulahi Dimeji; Awodugba, Ayodeji O.; Solar cell Collaboration

    2016-03-01

    Transparent conducting antimony-doped tin oxide (ATO) films have been deposited on glass substrates by home made spray pyrolysis technique. The structural, electrical and optical properties of the ATO films have been investigated as a function of Sb-doping level and annealing temperature. The optimum target composition for high conductivity and low resistivity was found to be 20 wt. % SnSb2 + 90 wt. ATO. Under optimized deposition conditions of 450oC annealing temperature, electrical resistivity of 5.2×10-4 Ω -cm, sheet resistance of 16.4 Ω/sq, average optical transmittance of 86% in the visible range, and average optical band-gap of 3.34eV were obtained. The film deposited at lower annealing temperature shows a relatively rough, loosely bound slightly porous surface morphology while the film deposited at higher annealing temperature shows uniformly distributed grains of greater size. Keywords: Annealing, Doping, Homemade spray pyrolysis, Tin oxide, Resistivity

  18. Spray pyrolysis deposition of Cu3BiS3 thin films

    International Nuclear Information System (INIS)

    Wittichenite Cu3BiS3 semiconductor thin films were deposited on glass slides within a range in substrate temperature from 250 °C to 400 °C via spray pyrolysis approach. Effects of substrate temperature on crystal structure, surface morphology, and optical property of Cu3BiS3 films were investigated in details. Pictures from a scanning electron microscope revealed that the as-prepared films in polycrystalline nature were uniform and comprised of close-packed fine nanoparticles, which grew up greatly by increasing substrate temperature to 350 °C. The as-prepared Cu3BiS3 film exhibited a direct optical band gap between 1.65 eV and 1.72 eV. - Highlights: • Depositing wittichenite Cu3BiS3 thin films via spray pyrolysis • Polycrystalline Cu3BiS3 films were comprised of densely packed nanoparticles. • Direct optical band gaps of the films lie between 1.65 eV and 1.72 eV

  19. Spray pyrolysis deposition of Cu{sub 3}BiS{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Sheng, E-mail: sliu@swu.edu.cn; Wang, Xuebin; Nie, Longying; Chen, Lijin; Yuan, Ruo

    2015-06-30

    Wittichenite Cu{sub 3}BiS{sub 3} semiconductor thin films were deposited on glass slides within a range in substrate temperature from 250 °C to 400 °C via spray pyrolysis approach. Effects of substrate temperature on crystal structure, surface morphology, and optical property of Cu{sub 3}BiS{sub 3} films were investigated in details. Pictures from a scanning electron microscope revealed that the as-prepared films in polycrystalline nature were uniform and comprised of close-packed fine nanoparticles, which grew up greatly by increasing substrate temperature to 350 °C. The as-prepared Cu{sub 3}BiS{sub 3} film exhibited a direct optical band gap between 1.65 eV and 1.72 eV. - Highlights: • Depositing wittichenite Cu{sub 3}BiS{sub 3} thin films via spray pyrolysis • Polycrystalline Cu{sub 3}BiS{sub 3} films were comprised of densely packed nanoparticles. • Direct optical band gaps of the films lie between 1.65 eV and 1.72 eV.

  20. Analysis of carrier gas flow rate effect on hydroxyapatite particle formation in ultrasonic spray pyrolysis

    Science.gov (United States)

    Widiyastuti, W.; Setiawan, Adhi; Nurtono, Tantular; Winardi, Sugeng

    2016-02-01

    Ultrasonic spray pyrolysis has been well-known process for producing fine particles from single and multicomponent materials. Here, the effect of carrier gas flow rate in ultrasonic spray pyrolysis process was studied in the particle formation of hydroxyapatite using solution precursor of Ca(CH3COO)2 and (NH4)2HPO4 with Ca/P ratio of 1.67. The experimental analysis was accompanied with computational fluid dynamics (CFD) simulation for comparison. In the simulation, the evaporation of the solvent in the droplets, a second evaporation due to crust formation, the decomposition reaction of the precursor involving the transfer of heat and mass transfer from droplet to surrounding were considered. By maintaining temperature at 900 °C, the residence time increased with decreasing the carrier gas flow rate led to the increasing the evaporation rate and the reacted fraction of the precursor. The predicted and experimental results of average particles size were agreed well with discrepancy 6.3%.

  1. Properties of ZnO:Bi thin films prepared by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Highlights: •Transparent and conductive Bi doped ZnO films deposited by spray pyrolysis technique. •The incorporation of Bi in ZnO film was studied by X-ray photoelectron microscopy. •Effect of Bi doping on the structural, optical and electrical properties of the films. •Bi doped ZnO films can be used as transparent conductors. -- Abstract: Undoped and Bi doped zinc oxide thin films were deposited on glass substrate at 450 °C using spray pyrolysis technique. The X-ray diffraction studies shows that Bi doped ZnO films are polycrystalline hexagonal structure with a preferred orientation along (1 0 1) direction. Crystallites size of the films decreases with increasing doping concentration. Scanning electron microscope image shows change in the surface morphology. The composition of Zn, O and Bi elements in the undoped and Bi doped ZnO films were investigated by X-ray photoelectron spectroscopy. Bi doped ZnO thin films show a transparency nearly 75% in the visible region. The optical band gap of ZnO thin films reduces from 3.25 eV to 3.12 eV with an increase in Bi concentration from 0 to 5 at.% respectively. Electrical conductivity of ZnO thin films increased from 0.156 to 6.02 S/cm with increasing Bi dopant concentration from 0% to 5% respectively

  2. Growth of AgInS2 thin films by ultrasonic spray pyrolysis technique

    International Nuclear Information System (INIS)

    Silver Indium Di-sulfide (AgInS2) thin films are deposited using ultrasonic spray pyrolysis technique and the effect of substrate temperature (Ts) on film growth is studied by varying the temperature from 250 to 400 °C. From the structural analysis, orthorhombic AgInS2 phase is identified with preferential orientation along (002) plane. Further analysis with Raman revealed the coexistence of Cu–Au ordered and chalcopyrite structures in the films. Stoichiometric films are obtained at Ts of 300 °C. Above 300 °C, the film conductivity changed from p to n-type and the grain size decreased. The band gap of AgInS2 films varied from 1.55 to 1.89 eV and absorption coefficient is found to be > 104 cm−1. The films have sheet resistance in the range of 0.05 to 1300 Ω/□. Both p and n type films are prepared through this technique without any external doping. - Highlights: • Silver Indium Di-sulfide (AgInS2) films are grown using ultrasonic spray pyrolysis. • AgInS2 films showed coexistence of orthorhombic and tetragonal structures. • Band gap increased up to 1.89 eV. • 0.96 μm thick p type films are prepared without external doping. • Stoichiometry is achieved for the films prepared at 300 °C

  3. Chemical Vapor Deposition of Silicon from Silane Pyrolysis

    Science.gov (United States)

    Praturi, A. K.; Lutwack, R.; Hsu, G.

    1977-01-01

    The four basic elements in the chemical vapor deposition (CVD) of silicon from silane are analytically treated from a kinetic standpoint. These elements are mass transport of silane, pyrolysis of silane, nucleation of silicon, and silicon crystal growth. Rate expressions that describe the various steps involved in the chemical vapor deposition of silicon were derived from elementary principles. Applications of the rate expressions for modeling and simulation of the silicon CVD are discussed.

  4. Synthesis of ZnO nanorods by spray pyrolysis for H2S gas sensor

    International Nuclear Information System (INIS)

    Highlights: ► Hexagonal pillar shaped ZnO nanorods with different sizes have been successfully synthesized by spray pyrolysis technique. ► ZnO nanorods thin films showed much better sensitivity and stability than the conventional materials to H2S gas (100 ppm) at 50 °C. ► This ZnO thin film has potential in application of room temperature H2S gas sensing. - Abstract: Hexagonal pillar shaped ZnO nanorods with different sizes have been successfully synthesized by spray pyrolysis technique (SPT). The equal amount of methanol and water is used as a solvent to dissolve the AR grade Zinc acetate for precursor solution. This solution is sprayed on to the glass substrate heated at 350 °C. The films were characterized by ultra-violet spectroscopy (UV), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The deposition of thin films results in a layer comprising well-shaped hexagonal ZnO nanorods with diameter of 90–120 nm and length of up to 200 nm. The gas sensing properties of these films have been investigated for various interfering gases such as CO2, CO, ethanol, NH3 and H2S, etc. at operating temperature from 30° (room temperature) to 450 °C. The results indicate that the ZnO nanorods thin films showed much better sensitivity and stability than the conventional materials to H2S gas (100 ppm) at 50 °C. The hexagonal pillar shaped ZnO nanorods can improve the sensitivity and selectivity of the sensors.

  5. Enhanced photoelectrochemical performance of Ag-ZnO thin films synthesized by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Highlights: → Synthesis of Ag-ZnO nanocomposites by spray pyrolysis technique. → Examine the effect of Ag doping on the structural, morphological optical, and photoelectrochemical properties. → Surface Plasmon Resonance phenomenon of the spray deposited Ag-ZnO nanocomposites. → Enhancement in photoelectrochemical performance of ZnO thin films after Ag doping. - Abstract: Silver doped zinc oxide (Ag-ZnO) thin films were deposited on glass and tin doped indium oxide (ITO) coated glass substrates by using pneumatic spray pyrolysis technique (SPT) at 450 deg. C from aqueous solutions of zinc acetate and silver nitrate precursors. The effect of silver doping on structural, morphological and optical properties of films was studied. The XRD spectra of the Ag-ZnO films indicate the polycrystalline nature having hexagonal crystal structure. SEM micrographs show the uniform distribution of spherical grains of about 80-90 nm grain size for the pure ZnO thin films. The Ag nanoparticles are clearly visualized in SEM images of Ag-ZnO samples. The optical band gap energy decreases as the percentage of silver doping increases. Surface Plasmon Resonance (SPR) related phenomena are observed and correlated to the optical properties of Ag-ZnO thin films. The overall photoelectrochemical (PEC) performance of the samples was investigated and discussed. Moreover, the samples are more photoactive as compare to the pure ZnO sample and the sample ZnOAg15 shows the highest current. The photocurrent increases upto 249 μA cm-2 and 303 μA cm-2 in visible light and in UV illumination, respectively, and then decreases as the Ag doping increases into the film.

  6. Nanostructured ZnO films with various morphologies prepared by ultrasonic spray pyrolysis and its growing process

    Czech Academy of Sciences Publication Activity Database

    Ma, H.L.; Liu, Z.W.; Zeng, D.C.; Zhong, M.L.; Yu, H.Y.; Mikmeková, Eliška

    2013-01-01

    Roč. 283, 15 October (2013), s. 1006-1011. ISSN 0169-4332 R&D Projects: GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : ZnO * Nanostructure * Film * Ultrasonic spray pyrolysis Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 2.538, year: 2013

  7. Nanocrystalline thin films of CuInS2 grown by spray pyrolysis

    International Nuclear Information System (INIS)

    Nanocrystalline thin films of CuInS2 were grown on glass substrates using the spray pyrolysis technique. An aqueous mixture of solutions of CuCl2, InCl3 and CS(NH2)2 was converted into a fine colloidal solution by adding acetonitrile, and was then sprayed on to heated glass substrates, to produce the nanocrystalline films of CuInS2. The films were characterized using XRD, TEM, electron diffraction, SEM, EDAX, AFM and optical transmission spectra. AFM and TEM micrographs together with electron diffraction and XRD show that the films grown in the temperature range 275-325 deg. C are made up of single phase nano-sized (10-25 nm) particles of CuInS2. XRD calculations show that the crystallite size of the films ranges from 8 nm to about 15 nm. Optical absorption studies show that the band gap of the sprayed CuInS2 films is in the range 1.48-1.54 eV.

  8. Direct synthesis of hBN/MWCNT composite particles using spray pyrolysis

    International Nuclear Information System (INIS)

    A spray-pyrolysis technique for the direct synthesis of multi-wall carbon nanotubes (MWCNTs) on a hexagonal boron nitride (hBN) matrix has been developed. Cobalt palladium (CoPd) nanoparticles, hBN nanoparticles, and ethanol were used as the catalyst, matrix, and carbon source, respectively. The materials were mixed by ultrasonication and then sprayed into a vertical tubular reactor at 900 deg. C under an argon flow of 2 L/min. As the aerosol passed through the reactor, the following processes occurred sequentially: solvent evaporation; formation of spherical particles composed of hBN and CoPd nanoparticles; catalytic decomposition of ethanol; and CNT growth on the surface of the CoPd nanoparticles. As a result, spherical-hairy particles were obtained, and both the hBN hexagonal phase and primary particle diameter were maintained during the reaction pathway because of the short residence time (1 s). The results showed that the spray-dried particle size and population of MWCNTs depended on the residence time within the heating zone and on the initial CoPd concentration. The novel synthesis technique described in this paper can be broadly applied to the production of various types of functional inorganic material/CNT composite particles

  9. Synthesis and characterization of nickel oxide thin films deposited on glass substrates using spray pyrolysis

    International Nuclear Information System (INIS)

    A simple and inexpensive spray pyrolysis technique was employed to deposit nickel oxide (NiO) thin films from hydrated nickel chloride salt solution onto amorphous glass substrate. The as-deposited films were transparent, uniform and well adherent to the glass substrate. The effect of the substrate temperature, the volume and the concentration of the sprayed solution on the structural, optical and electrical properties was studied using X-ray diffraction, optical transmittance, four point probe, scanning electron microscopy and atomic force microscopy. The structural analyses show that all the samples have a cubic structure. It was found that the increase in the volume of sprayed solution leads to an increment in the crystallite size of NiO and improves the homogeneity of the film. Optical measurements have shown that an increase in the thickness of the layer results in a decrease in the optical transmission, but it remains higher than 70% even if the thickness exceeds 600 nm. At the same time, the optical gap decreases from 3.7 to 3.55 eV when the thickness increases from 133 to 620 nm. Low values of the electrical resistivity (less than 10 Ω cm) were obtained for thin films with thicknesses less than about 240 nm, but for higher thicknesses the resistivity increases linearly to reach about 170 Ω cm for a thickness of 620 nm.

  10. Preparation of High JcYBCO Films on LAO by Spray Pyrolysis Process Using Nitrate Precursors

    International Nuclear Information System (INIS)

    High Jc over 1 MA/cm2 YBCO film has been successfully prepared using nitrate precursors by spray pyrolysis method. Aerosol droplets generated using a concentric spray nozzle were directly sprayed on a LaAlO3 (100) single crystal substrate. The cation ratio of precursor solution was Y:Ba:Cu=1:2.65:1.35. The distance between nozzle and substrate was 15 cm. Deposition temperature was ranging from 750 to 800 degrees C. Deposition pressure was 100 Torr, and oxygen partial pressure was varied from 10 Torr to 50 Torr. The microstructure, phase formation, texture development and superconducting properties of deposited films were largely changed with oxygen partial pressure. Deposited films showed a texture with(001) planes parallel to substrate plane. High quality film was obtained when film was deposited at degrees C with an oxygen partial pressure of 30 Torr. The critical current density(Jc) of the YBCO film was 1.75 MA/cm2 at 77 K and self-field.

  11. Optical properties of CuInS2 thin films prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Polycrystalline CuInS2 (CIS) absorber films for solar cells were prepared by spray pyrolysis of aqueous solution of copper chloride, indium chloride and thiourea onto heated glass substrates. By optimizing the spray parameters, such as reducing/increasing the temperature of the substrate and molar ratio of Cu/In in the spraying solution, the optical characteristics of films, which are well matched to the solar spectrum, were identified. In all cases, those CIS thin films were of p-type conductivity. Transmission measurements were performed to examine the optical properties of the films; the absorption coefficient and the optical band gap of the films were calculated by transmission spectra. The absorption spectra of the films showed that this compound is a direct band gap one and its gap varied between 1.30 - 1.78 eV. Those thin films were analyzed by X-ray diffraction in order to understand the effect of layers structure on their optical properties. (author)

  12. Mass Production of LiFePO4/C Powders by Large Type Spray Pyrolysis Apparatus and Its Application to Cathode for Lithium Ion Battery

    OpenAIRE

    Takashi Ogihara; Takayuki Kodera; Motofumi Yamada; Shinsuke Akao

    2010-01-01

    Spherical LiFePO4/C powders were successfully produced at a rate of 100 g/h using a large type spray pyrolysis apparatus. Organic compounds such as citric acid and sucrose were used as carbon sources. Scanning electron microscopy observation showed that they had a spherical morphology with nonaggregation. X-ray diffraction analysis revealed that the olivine phase was obtained by heating at 600∘C under argon (95%)/hydrogen (5%) atmosphere. The chemical composition of LiFe...

  13. Comparative study of nano-structured CdS thin films prepared by CBD and spray pyrolysis: Annealing effect

    International Nuclear Information System (INIS)

    CdS films were deposited on glass and ITO-covered glass substrates by two techniques: chemical bath deposition (CBD) and spray pyrolysis technique. CdCl2 and thiocarbamide were used as basic precursors in both cases. After deposition, films were isothermally annealed in evacuated (1.3 Pa) quartz ampoules at 450 deg. C for 5 min and slowly cooled down to room temperature. The morphology of the films was characterized by electron scanning microscopy (SEM), electrical resistivities were calculated from I-V measurements, optical properties by UV-Vis and PL, and the presence of the chlorine in the films was detected by wavelength-dispersive analysis (WDX). Annealing decreased the resistivity of the sprayed CdS films on glass up to two orders of magnitude (from 50 Ω.cm down to 0.1 Ω.cm), while the CBD CdS does not changed the resistivity. Moreover, with the aid of post-deposition annealing, we succeeded to reduce the series resistance of CdS/ITO structure by an order of magnitude. This should contribute to the smaller series resistance of the whole solar cell. As a result of annealing optical band gap (E g) for CBD CdS shifted from 2.51 eV down to 2.42 eV, whereas the E g of sprayed films (2.46 eV) did not change. All the films have high transparency over 80% in the visible spectrum (520-850 nm). The further development of annealing process for the improvement of continuity and conductivity of ultra-thin CBD CdS films is discussed

  14. Preparation of NaTaO3 by Spray Pyrolysis and Evaluation of Apparent Photocatalytic Activity for Hydrogen Production from Water

    Directory of Open Access Journals (Sweden)

    Hyun Woo Kang

    2008-01-01

    Full Text Available NaTaO3 photocatalyst was prepared by spray pyrolysis process and tested as photocatalyst for water splitting under UV light. Precursor solution was prepared from NaNO3 and Ta(OC2H55 in nitric acid solution and spray-pyrolyzed in air at between 973 and 1273 K. Considerable enhancement of photocatalytic activity was achieved by loading 0.05∼0.2 wt% of NiO on the surface of NaTaO3. The NiO loading was more effective on the NaTaO3 synthesized by spray pyrolysis in comparison with that synthesized by solid-state reaction. The quantum yield (QY of NiO/NaTaO3 photocatalyst was measured by chemical actinometry using potassium ferrioxalate and compared with the apparent photocatalytic activities (APA which would be more useful for the purpose of photocatalytic reactor design than the quantum yield. The apparent photocatalytic activity (APA was defined by the rate of hydrogen production divided by weight of catalyst, volume of reactant mixture, duration of irradiation, and power of UV lamp. The validity of the apparent photocatalytic activity (APA was discussed based on our results and reported activities of NaTaO3 photocatalyst loaded with or without NiO.

  15. Growth and characterization of V2O5 nanorods deposited by spray pyrolysis at low temperatures

    Science.gov (United States)

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

    2016-07-01

    Vanadium pentoxide (V2O5) nanorods were deposited by spray pyrolysis on preheated glass substrates at low temperatures. The influence of substrate temperature on the crystallization of V2O5 has been investigated. X-ray diffraction analysis (XRD) revealed that the films deposited at Tsub = 300°C were orthorhombic structures with preferential along (001) direction. Formation of nanorods from substrate surface which led to the formation of films with small-sized and rod-shaped nanostructure is observed by field scanning electron microscopy. Optical transmittance in the visible range increases to reach a maximum value of about 80% for a substrate temperature of 350°C. PL spectra reveal one main broad peak centered around 540 nm with high intensity.

  16. Synthesis of ZnO Microrods by the Spray Pyrolysis Technique

    Science.gov (United States)

    Ikhmayies, Shadia J.

    2016-08-01

    Zinc oxide (ZnO) microrods were synthesized by the spray pyrolysis technique on aluminum substrates at a substrate temperature of 350 ± 5°C. The samples were characterized by x-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM), and energy dispersion x-ray spectroscopy (EDX). XRD diffractograms presented the wurtzite (hexagonal) structure with (002) as the preferential orientation. The SEM observations showed typical microrods of hexagonal cross sections with lengths in the range 1.0-2.5 μm and diameter in the range 300-400 nm. XRF and EDX analysis revealed that the samples contain chlorine, and other impurities, which are related to the aluminum substrate and the starting material zinc chloride (ZnCl2). It is found that the microrods are rich in oxygen, which make them of potential use in gas sensors, besides solar cells, lithium ion batteries and other electo-optic devices.

  17. Structural, Optical and Electrical Properties of Thin Films Using Nebulizer Spray Pyrolysis Technique

    Directory of Open Access Journals (Sweden)

    R. Mariappan

    2013-01-01

    Full Text Available thin films have been deposited on glass substrates at substrate temperature 400°C through nebulizer spray pyrolysis technique. X-ray diffraction (XRD analysis shows that the films structure is changed from hexagonal to tetragonal. The high-resolution scanning electron microscopy (HRSEM studies reveal that the substrate is well covered with a number of grains indicating compact morphology with an average grain size 50–79 nm. Energy dispersive X-ray analysis (EDAX reveals the average ratio of the atomic percentage. Optical transmittance study shows the presence of direct transition. Band gap energy decreases from 3.33 to 2.87 eV with respect to the rise of Sn content. The electrical resistivity of the thin films was found to be 106 Ω-m.

  18. Characterization of MnWO4 with flower-like clusters produced using spray pyrolysis

    Institute of Scientific and Technical Information of China (English)

    Somchai THONGTEM; Surangkana WANNAPOP; Titipun THONGTEM

    2009-01-01

    MnWO4 (huebnerite) with flower-like clusters of nano-plates was produced from the solutions containing MnCl2·4H2O and Na2WO4·2H2O by the 300℃ spray pyrolysis. The phase was detected by X-ray diffraction (XRD) and selected area electron diffraction (SAED), and is in accordance with the results characterized using energy dispersive X-ray (EDX) analysis. The flower-like clusters of nano-plates were characterized using scanning and transmission electron microscopes (SEM and TEM), and their parallel lattice planes using a high resolution transmission electron microscope (HRTEM). Vibration spectra of the huebnerite structured products were characterized using Raman and Fourier transform infrared (FTIR) spectrometers. Their photoluminescence (PL) emissions are in the same spectral region at 405-412 nm.

  19. Domain switching in spray pyrolysis-deposited nano-crystalline BiFeO3 films

    International Nuclear Information System (INIS)

    Single-phase nano-scale BiFeO3 (BFO) films have been prepared under a controlled substrate temperature by a simple spray pyrolysis method. Fourier-transform infrared spectroscopy results indicate that single-phase BFO is deposited at low temperature. A magnetoelectric coupling to the anti-ferromagnetic and α-β phase transitions was observed at 350.2 and 832.8 °C, respectively. The capacitance-voltage (C-V) curves exhibit two coercive fields corresponding to ferroelastic (71° and 109°) and ferroelectric (180°) domains. Ferroelectric domain switching is dominant at lower electric fields. A non-volatile domain switching in the BFO films can prevent domain wall pinning and can enhance fatigue behavior in the films.

  20. Nano crystal SnO2:F films prepared by spray pyrolysis method

    International Nuclear Information System (INIS)

    Nano crystal thin films of fluorine doped tin oxide were prepared on glass substrates by the spray pyrolysis method. From X-ray diffraction patterns of the films, the structure and grain size of 9 nm and 14 nm were determined at temperatures of 390 oC and 420 oC, respectively. The transmission of the films has an average value of about 85% in the range of visible light, and the film thickness of 650 nm was estimated from the interference fingers. The optical band gap for direct allowed transitions is in the range from 4.0 eV to 4.17 eV, depending on the temperature of the substrates during films deposition. As prepared films show the sheet resistance of 15 Ω/cm2. The surface morphologies of the films were studied with SEM. (Author)

  1. Synthesis and characterization of spherical calcia stabilized zirconia nano-powders obtained by spray pyrolysis

    International Nuclear Information System (INIS)

    Fine, spherical Ca0.15Zr0.85O1.85 nano-powders were prepared by spray pyrolysis, starting from a mixed aqueous and ethylic solution of zirconium acetylacetonate and calcium acetate. The influence of solution concentration, furnace temperature, mass flow of carrier gas and voltage of precipitator on microstructure, average particles size and recovery percentage were evaluated. The powders were synthesized without sintering, and for adequate preparation conditions, were mostly spherical, solid and narrowly size distributed. Average particle size ranges between 40 and 350 nm. Transmission electron micrographs showed that crystalline calcia stabilized zirconia particles were constituted by small crystallites, their size varying between 2 and 40 nm. X-ray diffraction analysis shows that powders obtained at low temperature were amorphous; for higher temperatures (∼800 deg. C), it is found the presence of the tetragonal and cubic phases

  2. Computational fluid dynamic modeling of the flame spray pyrolysis process for silica nanopowder synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Olivas-Martinez, Miguel; Sohn, Hong Yong, E-mail: h.y.sohn@utah.edu [University of Utah, Department of Metallurgical Engineering (United States); Jang, Hee Dong; Rhee, Kang-In [Korea Institute of Geoscience and Mineral Resources (KIGAM), Rare Metals Research Center (Korea, Republic of)

    2015-07-15

    A computational fluid dynamic model that couples the fluid dynamics with various processes involving precursor droplets and product particles during the flame spray pyrolysis (FSP) synthesis of silica nanopowder from volatile precursors is presented. The synthesis of silica nanopowder from tetraethylorthosilicate and tetramethylorthosilicate in bench- and pilot-scale FSP reactors, with the ultimate purpose of industrial-scale production, was simulated. The transport and evaporation of liquid droplets are simulated from the Lagrangian viewpoint. The quadrature method of moments is used to solve the population balance equation for particles undergoing homogeneous nucleation and Brownian collision. The nucleation rate is computed based on the rates of thermal decomposition and oxidation of the precursor with no adjustable parameters. The computed results show that the model is capable of reproducing the magnitude as well as the variations of the average particle diameter with different experimental conditions using a single value of the collision efficiency factor α for a given reactor size.

  3. Optimizing of Synthesis of Carbon Nano tubes Fabricated by Spray Pyrolysis Method

    International Nuclear Information System (INIS)

    Carbon nano tubes material was fabricated by spray pyrolysis method. Benzene as source of carbon and ferrocene as catalyst were used to fabricate carbon nano tubes. Temperature optimizing was conducted at varied temperature in range of 700, 800, 900 and 1000 oC. Meanwhile, composition optimizing of ferrocene to benzene was conducted at varied ratio of 1.5/50, 3/50 and 4.5/50 g/mL. The characterization of carbon nano tubes material was conducted by SEM and EDS. Based on the these characterizations, the optimum synthesis parameter of carbon nano tubes was at temperature of 900 oC and composition of 3/50 g/mL. Purification of carbon nano tubes was conducted by using HNO3 solution at varied concentration of 25, 45, 65 and 85%. The result of purification showed that the highest decrease of Fe can be achieved by using 65 % HNO3 solution. (author)

  4. Gas sensing application of nanocrystalline zinc oxide thin films prepared by spray pyrolysis

    Indian Academy of Sciences (India)

    Nisha R; K N Madhusoodanan; T V Vimalkumar; K P Vijayakumar

    2015-06-01

    Nanocrystalline oxygen-deficient ZnO thinfilm sensors were prepared by spray pyrolysis technique using zinc acetate dissolved in propanol and water as precursor. Response of the sensor to target gases NO2 and H2S is studied. At optimum temperature of 200° C, the sensors have a response of 3.32 to 7 ppm NO2 and 1.4 to 18 ppm of H2S gas. The analytical characterizations of the prepared sensors were performed using X-ray diffraction measurement, scanning electron microscopy, energy-dispersive X-ray spectroscopy and Raman spectroscopy. Dynamic response of sensors to different concentrations of NO2 and H2S gas was tested at optimum temperature. Experimental data revealed the sensors to be more selective to NO2 gas with satisfactory response and recovery time.

  5. Deposition of gold nanoparticles on glass substrate by ultrasonic spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Garza, Maria de la; Hernandez, Tomas [Laboratorio de Materiales I, Centro de Laboratorios Especializados, Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon. Av. Universidad s/n Cd. Universitaria, C.P. 66451, San Nicolas de los Garza, Nuevo Leon (Mexico); Colas, Rafael [Programa Doctoral en Ingenieria de Materiales, Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon. Av. Universidad s/n Cd. Universitaria, C.P. 66451, San Nicolas de los Garza, Nuevo Leon (Mexico); Gomez, Idalia, E-mail: mgomez@fcq.uanl.mx [Laboratorio de Materiales I, Centro de Laboratorios Especializados, Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon. Av. Universidad s/n Cd. Universitaria, C.P. 66451, San Nicolas de los Garza, Nuevo Leon (Mexico)

    2010-10-25

    Ultrasonic spray pyrolysis was used to deposit gold nanoparticles on a glass substrate using ZrO{sub 2} as a surrounding medium. The deposition was made using three flow rates of caring gas. The characterization was made by UV-Vis spectroscopy, X-ray diffraction, scanning electronic microscopy and atomic force microscopy. The UV-Vis spectra showed that the surface plasmon resonance peak, indicative of the presence of gold nanoparticles, was shown to shift towards the red spectrum as the flow rate increased; this shift can be associated to the change in size of the particles, which are assumed to grow on a {l_brace}1 1 1{r_brace} planes, as was detected by X-ray diffraction. Gold nanoparticles of spheroidal morphology with a relation of around 2:1 were detected by scanning electron microscopy, these observations were confirmed by atomic force microscopy.

  6. Liquid-feed flame spray pyrolysis synthesis of oxide nanopowders for the processing of ceramic composites

    Science.gov (United States)

    Taylor, Nathan John

    In the liquid-feed flame spray pyrolysis (LF-FSP) process, alcohol solutions of metalloorganic precursors are aerosolized by O2 and combusted. The metal oxide combustion products are rapidly quenched (researchers to further refine microstructural size. LF-FSP flame temperatures were mapped using different alcohols with different heats of combustion: methanol, ethanol, 1-propanol, and n-butanol. The effect of different alcohols on particle size and phase was determined through studies on Al2O3, Y2O3 and TiO2 nanopowders. The final studies describe the morphology of composite nanopowders produced in the WO3-TiO2 and CuO-TiO2 systems. The composite nanopowders have novel morphology, and may offer novel electronic, optical, or catalytic properties.

  7. Studies on electrochromic properties of nickel oxide thin films prepared by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Kadam, L.D.; Patil, P.S. [Thin film physics laboratory, Department of Physics, Shivaji University, - 416 004 Kolhapur (India)

    2001-11-01

    Electrochromic nickel oxide thin films were prepared by using a simple and inexpensive spray pyrolysis technique (SPT) onto fluorine-doped tin oxide (FTO) coated glass substrates from nickel chloride solution. Transparent NiO-thin films were obtained at a substrate temperature 350C. The films were cubic NiO with preferred orientation in the (111) direction. Infrared spectroscopy results show presence of free hydroxyl ion and water in nickel oxide thin films. The electrochromic properties of the thin films were studied in an aqueous alkaline electrolyte (0.1M KOH) using cyclic voltammetry (CV), chronoamperometry (CA) and spectrophotometry. The films exhibit anodic electrochromism, changing colour from transparent to black. The colouration efficiency at 630nm was calculated to be 37cm{sup 2}/C.

  8. Computational fluid dynamic modeling of the flame spray pyrolysis process for silica nanopowder synthesis

    International Nuclear Information System (INIS)

    A computational fluid dynamic model that couples the fluid dynamics with various processes involving precursor droplets and product particles during the flame spray pyrolysis (FSP) synthesis of silica nanopowder from volatile precursors is presented. The synthesis of silica nanopowder from tetraethylorthosilicate and tetramethylorthosilicate in bench- and pilot-scale FSP reactors, with the ultimate purpose of industrial-scale production, was simulated. The transport and evaporation of liquid droplets are simulated from the Lagrangian viewpoint. The quadrature method of moments is used to solve the population balance equation for particles undergoing homogeneous nucleation and Brownian collision. The nucleation rate is computed based on the rates of thermal decomposition and oxidation of the precursor with no adjustable parameters. The computed results show that the model is capable of reproducing the magnitude as well as the variations of the average particle diameter with different experimental conditions using a single value of the collision efficiency factor α for a given reactor size

  9. One-step synthesis of titanium oxide nanoparticles by spray pyrolysis of organic precursors

    Energy Technology Data Exchange (ETDEWEB)

    Wang Weining [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi, Hiroshima 739-8527 (Japan); Lenggoro, I. Wuled [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi, Hiroshima 739-8527 (Japan); Terashi, Yoshitake [Kyocera Corporation R and D Center, 1-4 Yamashita-Cho, Kokubu, Kagoshima 899-4312 (Japan); Kim, Tae Oh [School of Civil and Environmental Engineering, Kumoh National University of Technology, Kyungbuk 730-710 (Korea, Republic of); Okuyama, Kikuo [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi, Hiroshima 739-8527 (Japan)]. E-mail: okuyama@hiroshima-u.ac.jp

    2005-11-25

    Titanium oxide (titania) nanoparticles (with a nominal size of about 10 nm) were synthesized directly from three organic precursors: titanium tetraisopropoxide (TTIP), and water-soluble titanium sources TC-300[reg] and TC-400[reg], by using a low-pressure spray pyrolysis (LPSP) method. Effects of temperature, solvent, concentration and precursor type have been investigated systematically. We found that a higher temperature and a higher concentration were beneficial for the formation of nanoparticles. Addition of ethanol as a co-solvent improved breakup of droplets, and subsequently formation of nanoparticles. Water-soluble titanium sources showed great potentials for preparation of titania nanoparticles. The nominal size of nanoparticles calculated from electron microscopical images agreed well with that estimated from corresponding X-ray diffraction patterns, implying that nanoparticles were single crystals. The possible mechanism of particle formation in the LPSP process is also provided.

  10. Critical parameters for the preparation of Tl-1223 superconducting films by spray pyrolysis

    International Nuclear Information System (INIS)

    Thick films of the high temperature TlBa2Ca2Cu3Oz superconductor have been prepared from a precursor Ba2Ca2Cu3Oz obtained by spray pyrolysis. In this paper, we report on the parameters which mainly control the formation of the superconducting phase: the composition of the nitrates solution, the substrate temperature and the subsequent ex-situ thallination annealing. The sample were analyzed by X-ray diffraction and by secondary electron microscopy. Epitaxial film (1 to 2 μm thick) with a critical temperature Tc=107 K and a critical density of current Jc(77 K, 0T)=2.103 A/cm2 have been obtained. (orig.)

  11. Synthesis of ZnO Microrods by the Spray Pyrolysis Technique

    Science.gov (United States)

    Ikhmayies, Shadia J.

    2016-04-01

    Zinc oxide (ZnO) microrods were synthesized by the spray pyrolysis technique on aluminum substrates at a substrate temperature of 350 ± 5°C. The samples were characterized by x-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM), and energy dispersion x-ray spectroscopy (EDX). XRD diffractograms presented the wurtzite (hexagonal) structure with (002) as the preferential orientation. The SEM observations showed typical microrods of hexagonal cross sections with lengths in the range 1.0-2.5 μm and diameter in the range 300-400 nm. XRF and EDX analysis revealed that the samples contain chlorine, and other impurities, which are related to the aluminum substrate and the starting material zinc chloride (ZnCl2). It is found that the microrods are rich in oxygen, which make them of potential use in gas sensors, besides solar cells, lithium ion batteries and other electo-optic devices.

  12. Photovoltaic properties of ZnO/CdTe heterojunctions prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    An extended investigation has been made of the electrical and photovoltaic properties of heterojunctions prepared by spray-pyrolysis deposition of thin ZnO films on single-crystal p-type CdTe. The principal experimental variables were the substrate temperature and the postdeposition temperature for annealing in H2. Under actual sunlight the optimum cell showed an open-circuit voltage of 0.54 V, a short-circuit current of 19.5 mA/cm2, and a solar efficiency (referred to the active area) of 8.8%, the highest value obtained to date for an authentic heterojunction on CdTe. The nature of the forward transport mechanism has been investigated, and a tunneling model in which bulk and interface deep traps control the forward characteristics is shown to provide good correlation with the experimental data

  13. Superconducting Bi-Ca-Sr-Cu oxide thin films by spray pyrolysis of metal acetates

    International Nuclear Information System (INIS)

    Superconducting Bi-Ca-Sr-Cu oxide thin films have been prepared on ZrO2-coated silicon (111) wafers by spray pyrolysis of metal acetate precursors followed by rapid annealing to 850 0C in air. Resistivity measurements indicate a broad superconducting transition with T/sub c/ onset near 90 K and zero resistivity below 60 K. The films are highly oriented with the c axis normal to the substrate surface and can be indexed to a tetragonal structure with lattice parameters of a = 3.832(1) A and c = 30.78(5) A. Both x-ray photoelectron spectroscopy and x-ray diffraction measurements indicate the loss of Ca to the ZrO2 buffer layer

  14. Properties of antimony doped ZnO thin films deposited by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Sadananda Kumar, N., E-mail: sadanthara@gmail.com; Bangera, Kasturi V.; Shivakumar, G. K. [National Institute of Technology Karnataka, Surathkal, Thin Films Laboratory, Department of Physics (India)

    2015-07-15

    Antimony (Sb) doped zinc oxide (ZnO) thin films were deposited on the glass substrate at 450°C using spray pyrolysis technique. Effect of Sb doping on surface morphology structural, optical and electrical properties were studied. X-ray diffraction (XRD) analysis showed that both the undoped and doped ZnO thin films are polycrystalline in nature with (101) preferred orientation. SEM analysis showed a change in surface morphology of Sb doped ZnO thin films. Doping results in a marked increase in conductivity without affecting the transmittance of the films. ZnO films prepared with 3 at % Sb shows the lowest resistivity of 0.185 Ohm cm with a Hall mobility of 54.05 cm{sup 2} V{sup –1} s{sup –1}, and a hole concentration of 6.25 × 10{sup 17} cm{sup –3}.

  15. Nanostructure and magnetic properties of magnesium ferrite thin films deposited on glass substrate by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Arabi, H., E-mail: arabi-h@um.ac.ir [Magnetism and Superconducting Research Laboratory, Department of Physics, Faculty of Science, University of Birjand, Birjand (Iran, Islamic Republic of); Department of Physics, Faculty of Science, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Khalili Moghadam, N. [Magnetism and Superconducting Research Laboratory, Department of Physics, Faculty of Science, University of Birjand, Birjand (Iran, Islamic Republic of)

    2013-06-15

    The spinel MgFe{sub 2}O{sub 4} thin films were prepared on the glass substrates at T{sub S}=400 °C by the spray pyrolysis deposition method. Structural and magnetic properties of the calcinated thin films at different temperatures were also investigated. By changing the calcination temperature from 400 to 600 °C, the crystallite size increased from 10 to 15 nm and the crystallinity of the films improved slightly. Thickness of the films calcinated at 400 and 600 °C were 0.648 and 1.473 μm respectively. However, the surface morphology of the films did not change considerably. Magnetic measurements, when the applied magnetic field was in parallel and perpendicular directions, showed the isotropic magnetic nature of the prepared films and their magnetic properties increased with the increment of calcination temperature. The H{sub c} value of thin films calcinated at 400 °C was about 168 Oe. - Highlights: ► Thin films of MgFe{sub 2}O{sub 4} are prepared via spray pyrolysis. ► All of the MgFe{sub 2}O{sub 4} films have nanostructure and the special magnetic properties. ► The surface morphology of films in different calcination temperatures is similar. ► The H{sub c} values of our films are independent of the applied field direction. ► The M{sub s} values in the plan and perpendicular directions are not the same.

  16. Synthesis and characterization of thin film electroluminescent devices all-prepared by ultrasonic spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Ramírez, E.B. [Universidad Autónoma de la Ciudad de México, Calle Prolongación San Isidro Núm. 151, Col. San Lorenzo Tezonco, Iztapalapa 09790, D. F., México (Mexico); Bizarro, M. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Coyoacán 04510, Distrito Federal, México (Mexico); Alonso, J.C., E-mail: alonso@unam.mx [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Coyoacán 04510, Distrito Federal, México (Mexico)

    2013-12-02

    Alternating current thin film electroluminescent devices have been fabricated using aluminum-doped zinc oxide (ZnO:Al) as transparent conducting layer, aluminum oxide (Al{sub 2}O{sub 3}) as insulating layers, and manganese-doped zinc sulfide (ZnS:Mn) as electroluminescent layer. All these films were deposited by the ultrasonic spray pyrolysis technique at the same temperature (450°) on glass substrates, forming a standard MISIM (metal–insulator–semiconductor–insulator–metal) configuration. The electroluminescence of MISIM devices with a total thickness of ∼ 1330 nm was investigated by applying a sinusoidal voltage with a frequency of 10 kHz. The devices showed orange-emission spectra centered at approximately 570 nm, characteristic of {sup 4}T{sub 1} → {sup 6}A{sub 1} radiative transitions of Mn{sup 2+} ions in the ZnS host, with a sharp intensity increase upon increasing the root mean square voltage above a threshold of 25 V and a rapid saturation for voltages higher than 38 V. The electroluminescent emission of these MISIM structures can be observed with the naked eye under ambient illumination. - Highlights: • Thin film electroluminescent devices were fabricated by ultrasonic spray pyrolysis at 450 °C. • The electroluminescent devices were fabricated on glass substrates. • ZnO:Al was used as transparent conductive layer. • ZnS:Mn and Al{sub 2}O{sub 3} were used as phosphor and insulating layers, respectively. • The electroluminescent devices have a low threshold operation voltage.

  17. Synthesis of Al2O3 thin films using laser assisted spray pyrolysis (LASP)

    International Nuclear Information System (INIS)

    Highlights: ► Alumina thin films were made by laser assisted spray pyrolysis at various laser powers. ► The particle size was found to increase with laser power. ► The refractive index of the films was studied using ellipsometry. ► The film stoichiometry was studied using X-ray photoelectron spectroscopy. ► The film/substrate interface was studied using ellipsometer and secondary ion mass spectrometer. - Abstract: The present study reports the development of a laser assisted ultrasonic spray pyrolysis technique and synthesis of dense optical alumina films using the same. In this technique ultrasonically generated aerosols of aluminum acetylacetonate dissolved in ethanol and a laser beam (Nd:YAG, CW, 1064 nm) were fed coaxially and concurrently through a quartz tube on to a hot substrate mounted on an X–Y raster stage. At the laser focused spot the precursor underwent solvent evaporation and solute sublimation followed by precursor vapor decomposition giving rise to oxide coating, the substrate is rastered to get large surface area coating. The surface morphology revealed coalescence of particles with increase in laser power. The observed particle sizes were 17 nm for films synthesized without laser and 18, 21 and 25 nm for films made with laser at 25, 38 and 50 W, respectively. Refractive index of the films synthesized increased from 1.56 to 1.62 as the laser power increased from 0 to 50 W. The stoichiometry of films was studied using XPS and the increase in interfacial layer thickness with laser power was observed from dynamic SIMS depth profiling and ellipsometry.

  18. Indium oxide thin-film transistors processed at low temperature via ultrasonic spray pyrolysis

    KAUST Repository

    Faber, Hendrik

    2015-01-14

    The use of ultrasonic spray pyrolysis is demonstrated for the growth of polycrystalline, highly uniform indium oxide films at temperatures in the range of 200-300 °C in air using an aqueous In(NO3)3 precursor solution. Electrical characterization of as-deposited films by field-effect measurements reveals a strong dependence of the electron mobility on deposition temperature. Transistors fabricated at ∼250 °C exhibit optimum performance with maximum electron mobility values in the range of 15-20 cm2 V -1 s-1 and current on/off ratio in excess of 106. Structural and compositional analysis of as-grown films by means of X-ray diffraction, diffuse scattering, and X-ray photoelectron spectroscopy reveal that layers deposited at 250 °C are denser and contain a reduced amount of hydroxyl groups as compared to films grown at either lower or higher temperatures. Microstructural analysis of semiconducting films deposited at 250 °C by high resolution cross-sectional transmission electron microscopy reveals that as-grown layers are extremely thin (∼7 nm) and composed of laterally large (30-60 nm) highly crystalline In2O3 domains. These unique characteristics of the In2O3 films are believed to be responsible for the high electron mobilities obtained from transistors fabricated at 250 °C. Our work demonstrates the ability to grow high quality low-dimensional In2O3 films and devices via ultrasonic spray pyrolysis over large area substrates while at the same time it provides guidelines for further material and device improvements.

  19. Simple way for preparation of ZnO films by surfactant mediated spray pyrolysis

    International Nuclear Information System (INIS)

    Highlights: ► ZnO was prepared by surfactant mediated spray pyrolysis. ► The film surface morphology can be enhanced by PVA addition. ► The PVA improves significant the photocatalytic activity of ZnO. ► The zinc acetate precursor is preferred for film preparation than nitrate one. - Abstract: Nanocrystalline porous ZnO films are deposited onto alumina foil substrates by polyvinyl alcohol (PVA) modified spray pyrolysis. Water and ethanol–water mixture were used for preparation of the sols. The effect of polyvinyl alcohol on the morphological and photocatalytical properties of ZnO films was studied. It was found that the polyvinyl alcohol plays important role in formation of porous films structure with ganglia like morphology. Relatively compact granular morphology was observed for the ZnO samples, grown without organic surfactant. The X-ray diffraction patterns revealed the formation of phase-pure ZnO thin films. The FTIR spectra and DTA-TG analyses of the precursor mixtures: Zn(CH3COOH)2·2H2O and Zn(NO3)2·6H20 with PVA revealed that ZnO is formed before the final decomposition of the polymer at 350 °C. It was observed that both: the acetate precursor and the organic surfactant could enhance significantly the photocatalytic properties of the ZnO films. The films obtained from sols, containing PVA showed better photocatalytic decolorization of Malachite Green dye, than the films, deposited from unmodified sols.

  20. Indium oxide thin-film transistors processed at low temperature via ultrasonic spray pyrolysis.

    Science.gov (United States)

    Faber, Hendrik; Lin, Yen-Hung; Thomas, Stuart R; Zhao, Kui; Pliatsikas, Nikos; McLachlan, Martyn A; Amassian, Aram; Patsalas, Panos A; Anthopoulos, Thomas D

    2015-01-14

    The use of ultrasonic spray pyrolysis is demonstrated for the growth of polycrystalline, highly uniform indium oxide films at temperatures in the range of 200-300 °C in air using an aqueous In(NO3)3 precursor solution. Electrical characterization of as-deposited films by field-effect measurements reveals a strong dependence of the electron mobility on deposition temperature. Transistors fabricated at ∼250 °C exhibit optimum performance with maximum electron mobility values in the range of 15-20 cm(2) V (-1) s(-1) and current on/off ratio in excess of 10(6). Structural and compositional analysis of as-grown films by means of X-ray diffraction, diffuse scattering, and X-ray photoelectron spectroscopy reveal that layers deposited at 250 °C are denser and contain a reduced amount of hydroxyl groups as compared to films grown at either lower or higher temperatures. Microstructural analysis of semiconducting films deposited at 250 °C by high resolution cross-sectional transmission electron microscopy reveals that as-grown layers are extremely thin (∼7 nm) and composed of laterally large (30-60 nm) highly crystalline In2O3 domains. These unique characteristics of the In2O3 films are believed to be responsible for the high electron mobilities obtained from transistors fabricated at 250 °C. Our work demonstrates the ability to grow high quality low-dimensional In2O3 films and devices via ultrasonic spray pyrolysis over large area substrates while at the same time it provides guidelines for further material and device improvements. PMID:25490965

  1. Synthesis of kerosene based nanocarbons by a nebulized spray pyrolysis method

    Science.gov (United States)

    Widjaja, Ongky; Arie, Arenst Andreas; Halim, Martin; Lee, Joong Kee

    2016-04-01

    In this work, kerosene oil based nanocarbons were synthesized by a nebulized spray pyrolysis method. This method was conducted at temperature of 700°C under a nitrogen inert atmospheric condition. Activated carbon and ferrocene were used as substrate and catalyst, respectively. Initially, ferrocene was dissolved in the oil with fixed concentration of 0.02 g/ml. The pyrolysis reaction was carried out by varying the operating time of 15, 30 and 45 minutes. The main aim of this work was to investigate the effect of varying the operation time on the morphology and structural characteristics of as-prepared carbon products. The morphology and structural characteristics of synthesized nanocarbons were examined by Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), and Raman Spectroscopy, respectively. SEM and TEM observations showed that nano carbons were formed as agglomerated carbon nanospheres (CNSs) and graphene for all variation of operating time. Furthermore, it was observed that the size of agglomerated CNSs was proportional with the operating time from 15 to 45 minutes. Raman analysis showed that the ratio between graphite like and disorder carbon structure (IG/ID)of carbon samples increased from operating time of 15 to 30 minutes, however the ratio decreased from 30 minutes to 45 minutes.

  2. Corrosion resistance of zirconium oxynitride coatings deposited via DC unbalanced magnetron sputtering and spray pyrolysis-nitriding

    Energy Technology Data Exchange (ETDEWEB)

    Cubillos, G.I., E-mail: gcubillos@unal.edu.co [Department of Chemistry, Group of Materials and Chemical Processes, Universidad Nacional de Colombia, Av. Cra. 30 No 45-03, Bogotá (Colombia); Bethencourt, M., E-mail: manuel.bethencourt@uca.es [Department of Materials Science, Metallurgy Engineering and Inorganic Chemistry, International Campus of Excellence of the Sea - CEI-MAR, University of Cadiz, Avda. República Saharaui s/n, 11510 Puerto Real, Cádiz (Spain); Olaya, J.J., E-mail: jjolayaf@unal.edu.co [Faculty of Engineering, Group of Materials and Chemical Processes, Universidad Nacional de Colombia, Av. Cra. 30 No 45-03, Bogotá (Colombia)

    2015-02-01

    Highlights: • New ZrO{sub x}N{sub y} films were deposited on stainless steel 316L using PSY-N and UBMS. • ZrO{sub x}N{sub y} rhombohedral polycrystalline film grew with PSY-N. • Zr{sub 2}ON{sub 2} crystalline structures, mostly oriented along the (2 2 2) plane, grew with UBMS. • Layers improved corrosion behavior in NaCl media, especially those deposited by UBMS. - Abstract: ZrO{sub x}N{sub y}/ZrO{sub 2} thin films were deposited on stainless steel using two different methods: ultrasonic spray pyrolysis-nitriding (SPY-N) and the DC unbalanced magnetron sputtering technique (UBMS). Using the first method, ZrO{sub 2} was initially deposited and subsequently nitrided in an anhydrous ammonia atmosphere at 1023 K at atmospheric pressure. For UBMS, the film was deposited in an atmosphere of air/argon with a Φair/ΦAr flow ratio of 3.0. Structural analysis was carried out through X-ray diffraction (XRD), and morphological analysis was done through scanning electron microscopy (SEM) and atomic force microscopy (AFM). Chemical analysis was carried out using X-ray photoelectron spectroscopy (XPS). ZrO{sub x}N{sub y} rhombohedral polycrystalline film was produced with spray pyrolysis-nitriding, whereas using the UBMS technique, the oxynitride films grew with cubic Zr{sub 2}ON{sub 2} crystalline structures preferentially oriented along the (2 2 2) plane. Upon chemical analysis of the surface, the coatings exhibited spectral lines of Zr3d, O1s, and N1s, characteristic of zirconium oxynitride/zirconia. SEM analysis showed the homogeneity of the films, and AFM showed morphological differences according to the deposition technique of the coatings. Zirconium oxynitride films enhanced the stainless steel's resistance to corrosion using both techniques. The protective efficacy was evaluated using electrochemical techniques based on linear polarization (LP). The results indicated that the layers provide good resistance to corrosion when exposed to chloride

  3. Effect of temperature on structural, optical and photoluminescence properties of polycrystalline CuInS2 thin films prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Copper indium disulphide (CuInS2), is a good absorber material for photovoltaic applications. In this work, CuInS2 is deposited by chemical spray pyrolysis on heated glass substrates. It is observed that the film growth temperature and the ion ratio Cu/In affects the structural and optical properties of CuInS2 thin films. This paper presents the effect of temperature on the growth (for the ion ratio Cu/In=1.25), optical and photoluminescence properties of sprayed CuInS2 films. The XRD patterns confirm the well defined single phase composition of CuInS2 films grown from 300 to 350 deg. C (at Cu/In=1.25) as optimum temperature for depositing well defined crystallites along (1 1 2) oriented CuInS2 thin films with chalcopyrite structure. D2d point symmetry group is associated with the CuInS2 crystallites with energy gap of 1.53 eV at room temperature. The chemical nature and the presence of additional phases are discussed based on the EDAX measurements. The absorption coefficient of sprayed CuInS2 films is found to be in the order of 105-106 cm-1 in the UV-visible region and the optical band gap decreases with increase in temperature. Defects-related photoluminescence properties are also discussed. CuInS2 polycrystalline films are prepared by the cost effective method of spray pyrolysis from the aqueous solutions of copper (II) chloride, indium (III) chloride and thiourea for synthesis on heated glass substrates.

  4. Electrochromic properties of nano-structured nickel oxide thin film prepared by spray pyrolysis method

    International Nuclear Information System (INIS)

    In this study, we present a simple method to improve the electrochromic properties of a nickel oxide thin film. The method involves a three-step process-(a) conducting indium tin oxide (ITO) nano-particles were first sprayed onto a conducting substrate to form a porous nano-structured ITO layer, (b) nickel oxide film was then deposited onto the nano-structured ITO layer by a spray pyrolysis technique, and (c) the substrate, ITO nano-particles layer and nickel oxide film were annealed at high temperature of 300 deg. C to improve adhesion of these three layers. The microstructure of the resulting electrochromic cell was investigated using scanning electron microscopy. It is evident that the nickel oxide film covers the surface of the ITO nano-particle layer and forms a nano-structured nickel oxide (NSNO) film. The switching time and contrast were characterized by Autolab PGSTAT12 potentiostat and Jasco V-570 spectrophotometer. The results suggest that the transmittance contrast and switching time of NSNO are slightly superior to those of a conventional nickel oxide (CNO) film. However, the cycling durability of NSNO can be much better than that of CNO

  5. Some physical properties of CdO:F thin films prepared by spray pyrolysis

    Science.gov (United States)

    Bagheri Khatibani, A.; Hallaj, Z. A.; Rozati, S. M.

    2015-12-01

    Different attractions of cadmium oxide in the field of materials science especially in semiconductor science and engineering encouraged us to study its physical properties. The preparation of a transparent conducting cadmium oxide doped with various concentration of fluorine (0%, 3%, 6%) in the spray solution on a glass substrate by spray pyrolysis is reported. The structural, morphological, electrical and optical properties were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), Hall effect and UV-visible spectrophotometry. Different optical quantities such as optical band gap, refractive index, extinction coefficient, Urbach energy, oscillator energy, dispersion energy and nonlinear optical susceptibility were determined. The XRD, SEM, Hall effect and AFM showed the doping concentration effects on CdO thin-films properties. Observations such as the decrease of the sheet resistance to 9.20 (Ω/Box), the mobility increase up to 29.3(cm2/V·s), the transmittance up to 84% and the increase of the band gap up to 2.76(eV) state the sample CdO:F 3% is the best candidate for transparent and conducting oxide application.

  6. Photocatalytically active Au/TiO2 films deposited by two-step spray pyrolysis

    International Nuclear Information System (INIS)

    Nanocrystalline TiO2 and surface gold-modified films (Au/TiO2) are obtained by two step spray pyrolysis process. Titanium tetrachloride (TiCl4) was used as inorganic titanium precursor. The Au nanoparticles were deposited on the surface of sprayed TiO2 films, obtained by the classical Turkevich method. The AFM analyses have revealed that the roughness of Au/TiO2 is twice lower than that of the reference titania film. Some globular species are visible on the surface, which could be either individual Au nanoparticles or Au nanoparticles’ agglomerates embedded into the TiO2 film. The photocatalytic activity in the oxidative degradation of Reactive Black 5 dye under visible light of the Au/TiO2 films was estimated in a semi-batch reactor. Surface gold modified TiO2 films revealed higher photocatalytic efficiency than the reference sample. Key words: Au nanoparticles, photocatalysis, azo dye, titania, nanosized

  7. Flame spray pyrolysis: An enabling technology for nanoparticles design and fabrication

    Science.gov (United States)

    Teoh, Wey Yang; Amal, Rose; Mädler, Lutz

    2010-08-01

    Combustion of appropriate precursor sprays in a flame spray pyrolysis (FSP) process is a highly promising and versatile technique for the rapid and scalable synthesis of nanostuctural materials with engineered functionalities. The technique was initially derived from the fundamentals of the well-established vapour-fed flame aerosols reactors that was widely practised for the manufacturing of simple commodity powders such as pigmentary titania, fumed silica, alumina, and even optical fibers. In the last 10 years however, FSP knowledge and technology was developed substantially and a wide range of new and complex products have been synthesised, attracting major industries in a diverse field of applications. Key innovations in FSP reactor engineering and precursor chemistry have enabled flexible designs of nanostructured loosely-agglomerated powders and particulate films of pure or mixed oxides and even pure metals and alloys. Unique material morphologies such as core-shell structures and nanorods are possible using this essentially one step and continuous FSP process. Finally, research challenges are discussed and an outlook on the next generation of engineered combustion-made materials is given.

  8. Large-scale manufacture of ZnO nanorods by flame spray pyrolysis

    International Nuclear Information System (INIS)

    Large quantities of ZnO nanorods (>3 kg/h throughput) were produced in the gas-phase by flame spray pyrolysis (FSP) of a zinc nitrate–ethanol precursor solution without employing any catalysts or dopants. The nanorods with diameters of 20–30 nm and aspect ratios as high as seven were collected as a dry powder. Several rods self-aligned by forming junctions at the basal planes, while some even assembled into tetrapods. The aspect ratio of the nanorods could be controlled by the concentration of the Zn ions in the starting precursor solution, its delivery rate, and the oxygen flow into the reactor. To the best of our knowledge, this is the first time that synthesis of high aspect ratio ZnO nanorods by FSP is reported. Previous lab-scale experiments always yielded rather spherical albeit slightly elongated nanoparticles unless dopants were added. Such a product powder was obtained here when the ethanol in the precursor solution was replaced by methanol at otherwise constant process conditions. This is attributed to different temperature–time histories of the particles in the flame based on which a mechanism for ZnO nanorod formation in spray flames is proposed.

  9. Large-scale manufacture of ZnO nanorods by flame spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Hembram, K., E-mail: kaliyan@arci.res.in; Sivaprakasam, D.; Rao, T. N. [International Advanced Research Center for Powder Metallurgy and New Materials (ARCI), Center for Nanomaterials (India); Wegner, K. [ETH Zuerich, Particle Technology Laboratory, Department of Mechanical and Process Engineering (Switzerland)

    2013-02-15

    Large quantities of ZnO nanorods (>3 kg/h throughput) were produced in the gas-phase by flame spray pyrolysis (FSP) of a zinc nitrate-ethanol precursor solution without employing any catalysts or dopants. The nanorods with diameters of 20-30 nm and aspect ratios as high as seven were collected as a dry powder. Several rods self-aligned by forming junctions at the basal planes, while some even assembled into tetrapods. The aspect ratio of the nanorods could be controlled by the concentration of the Zn ions in the starting precursor solution, its delivery rate, and the oxygen flow into the reactor. To the best of our knowledge, this is the first time that synthesis of high aspect ratio ZnO nanorods by FSP is reported. Previous lab-scale experiments always yielded rather spherical albeit slightly elongated nanoparticles unless dopants were added. Such a product powder was obtained here when the ethanol in the precursor solution was replaced by methanol at otherwise constant process conditions. This is attributed to different temperature-time histories of the particles in the flame based on which a mechanism for ZnO nanorod formation in spray flames is proposed.

  10. Doped nanocrystalline ZnO powders for non-linear resistor applications by spray pyrolysis method.

    Science.gov (United States)

    Hembram, Kaliyan; Vijay, R; Rao, Y S; Rao, T N

    2009-07-01

    Homogeneous and doped nanocrystalline ZnO powders (30-200 nm) were synthesized by spray pyrolysis technique. The spray pyrolysed powders were calcined in the temperature range of 500-750 degrees C. Formation of insulating pyrochlore phase started from 700 degrees C during the calcination itself. The calcined powders were compacted and sintered at different temperatures ranging from 900-1200 degrees C for 0.5-4 h. The densification behavior was found to be dependent on calcination temperature of the nanopowder. The resulting discs were found to have density (5.34-5.62 g/cc) in the range of 96-99% of theoretical density. The breakdown voltage value obtained for the nanopowder based non-linear resistor is 10.3 kV/cm with low leakage current density of 0.7 microA/cm2 and coefficient of nonlinearity as high as 193. The activation energy for grain growth of the doped ZnO nanopowder powders is 449.4 +/- 15 kJ/mol. PMID:19916460

  11. Deposition and characterization of ZnO thin films by modified pulsed-spray pyrolysis

    International Nuclear Information System (INIS)

    Zinc oxide (ZnO) thin films were deposited using modified pulsed-spray pyrolysis on glass substrates. Depositions were carried out using N2 as the carrier gas and analysed with respect to the rate of deposition. X-ray analysis revealed the presence of mixed crystallization with a nanocrystalline structure of about 6.9 nm dispersed in the amorphous matrix. A negative trend between the bandgap and resistivity was observed with the decrease in the deposition rate. A lowest bandgap of 3.1 eV with a resistivity value of 1.6 × 10−2 Ω cm was achieved at a lowest deposition rate of 1.3 nm min−1. Hot-probe measurement revealed the p-type conductivity for the film deposited at a lowest deposition rate of 1.3 nm min−1. Details about the influence of pulsed-spray deposition for the achievement of this negative trend between bandgap and resistivity will be discussed in this paper

  12. Effect of temperature during the spray pyrolysis synthesis of silver nanopowder

    International Nuclear Information System (INIS)

    We report the results of the synthesis and characterization of Ag, AgO, AgNO3 nanopowders or mixtures of them, obtained by spray pyrolysis technique. An aqueous solution of AgNO3 with a concentration of 0.2 mol/L was sprayed through a horizontal tubular furnace where the solvent was evaporated and pyrolytic reaction occurs producing AgNO3, AgO and Ag particles. The synthesis was made at 500, 600 and 700 oC. The obtained material was analyzed by Transmission Electron Microscopy, and the optimal temperature to obtain particles of around 10 nm was 600 oC. The X-rays and Electron Diffraction analysis determined the coexistence of the phases of Ag, AgO and AgNO3, whereas the measurement of x-rays fluorescence the presence of Ag was detected. The solution concentration and the carrier flow, the temperature and the temperature gradient in the furnace influence in the phase and size of the particle.. (author)

  13. Structural, optical and electrical properties of zinc oxide thin films deposited by a spray pyrolysis technique

    International Nuclear Information System (INIS)

    Zinc oxide (ZnO) thin films were deposited on glass substrates by spray pyrolysis technique decomposition of zinc acetate dihydrate in an ethanol solution with 30 mL of deposition rate, the ZnO thin films were deposited at two different temperatures: 300 and 350 °C. The substrates were heated using the solar cells method. The substrate was R217102 glass, whose size was 30 × 17.5 × 1 mm3. The films exhibit a hexagonal wurtzite structure with a strong (002) preferred orientation. The higher value of crystallite size is attained for sprayed films at 350 °C, which is probably due to an improvement of the crystallinity of the films at this point. The average transmittance of obtain films is about 90%–95%, as measured by a UV—vis analyzer. The band gap energy varies from 3.265 to 3.294 eV for the deposited ZnO thin film at 300 and 350 °C, respectively. The electrical resistivity measured of our films are in the order 0.36 Ω·cm. (semiconductor materials)

  14. Electrocatalytic upgrading of biomass pyrolysis oils to chemical and fuel

    Science.gov (United States)

    Lam, Chun Ho

    The present project's aim is to liquefy biomass through fast pyrolysis and then upgrade the resulting "bio-oil" to renewable fuels and chemicals by intensifying its energy content using electricity. This choice reflects three points: (a) Liquid hydrocarbons are and will long be the most practical fuels and chemical feedstocks because of their energy density (both mass and volume basis), their stability and relative ease of handling, and the well-established infrastructure for their processing, distribution and use; (b) In the U.S., the total carbon content of annually harvestable, non-food biomass is significantly less than that in a year's petroleum usage, so retention of plant-captured carbon is a priority; and (c) Modern technologies for conversion of sunlight into usable energy forms---specifically, electrical power---are already an order of magnitude more efficient than plants are at storing solar energy in chemical form. Biomass fast pyrolysis (BFP) generates flammable gases, char, and "bio-oil", a viscous, corrosive, and highly oxygenated liquid consisting of large amounts of acetic acid and water together with hundreds of other organic compounds. With essentially the same energy density as biomass and a tendency to polymerize, this material cannot practically be stored or transported long distances. It must be upgraded by dehydration, deoxygenation, and hydrogenation to make it both chemically and energetically compatible with modern vehicles and fuels. Thus, this project seeks to develop low cost, general, scalable, robust electrocatalytic methods for reduction of bio-oil into fuels and chemicals.

  15. MORPHOLOGICAL AND MICROSTRUCTURAL CHANGES DURING THE HEATING OF SPHERICAL CALCIUM ORTHOPHOSPHATE AGGLOMERATES PREPARED BY SPRAY PYROLYSIS

    Institute of Scientific and Technical Information of China (English)

    Kiyoshi Itatani; Mari Abe; Tomohiro Umeda; Ian J. Davies; Seiichiro Koda

    2004-01-01

    The microstructural changes taking place during heating of calcium orthophosphate (Ca3(PO4)2) agglomerates were examined in this study. The starting powder was prepared by the spray-pyrolysis of calcium phosphate (Ca/P air-liquid nozzle. The spray-pyrolyzed powder was found to be composed of dense spherical agglomerates with a mean diameter of 1.3 μm. This powder was further heat-treated at a temperature between 800 and 1400 ℃ for 10 min. When the spray-pyrolyzed powder was heated up to 900 ℃, only βCa3(PO4)2 was detected, and the mean pore size of the spherical agglomerates increased via the (i) elimination of residual water and nitrates, (ii) rearrangement of primary particles within the agglomerates, (iii) coalescence of small pores (below 0.1 μm), and (iv) coalescence of agglomerates with diameters below 1 μm into the larger agglomerates. Among the heat-treated powders, pore sizes within the spherical agglomerates were observed to be the largest (mean diameter: 1.8 μm) for the powder heat-treated at 900 ℃ for 10 min.With an increase in heat-treatment temperature up to 1000 ℃, the spherical agglomerates were composed of dense shells. Upon further heating up to 1400 ℃, the hollow spherical agglomerates collapsed as a result of sintering via the phase transformation from β- to α-Ca3(PO4)2 (1150 ℃), thus leading to the formation of a three-dimensional porous network.

  16. Fabrication of gradient porous LSM cathode by optimizing deposition parameters in ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Multiple-step ultrasonic spray pyrolysis was developed to produce a gradient porous lanthanum strontium manganite (LSM) cathode on yttria-stabilized zirconia (YSZ) electrolyte for use in intermediate temperature solid oxide fuel cells (IT-SOFCs). The effect of solvent and precursor type on the morphology and compositional homogeneity of the LSM film was first identified. The LSM film prepared from organo-metallic precursor and organic solvent showed a homogeneous crack-free microstructure before and after heat treatment as opposed to aqueous solution. With respect to the effect of processing parameters, increasing the temperature and solution flow rate in the specific range of 520-580 deg. C leads to change the microstructure from a dense to a highly porous structure. Using a dilute organic solution a nanocrystalline thin layer was first deposited at 520 deg. C and solution flow rate of 0.73 ml/min on YSZ surface; then, three gradient porous layers were sprayed from concentrated solution at higher temperatures (540-580 deg. C) and solution flow rates (1.13-1.58 ml/min) to form a gradient porous LSM cathode film with ∼30 μm thickness. The microstructure, phase crystallinity and compositional homogeneity of the fabricated films were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive analysis of X-ray (EDX). Results showed that the spray pyrolized gradient film fabricated in the temperature range of 520-580 deg. C is composed of highly crystalline LSM phase which can remove the need for subsequent heat treatment

  17. Thermal and chemical effects of turkey feathers pyrolysis.

    Science.gov (United States)

    Kluska, Jacek; Kardaś, Dariusz; Heda, Łukasz; Szumowski, Mateusz; Szuszkiewicz, Jarosław

    2016-03-01

    This study examines the thermal and chemical effects of the pyrolysis of turkey feathers. Research of feathers pyrolysis is important because of their increasing production and difficulties of their utilization. The experiments were carried out by means of thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and two pyrolytic reactors. The experimental investigation indicated that the feather material liquefies at temperatures between 210 and 240°C. This liquefaction together with the agglomeration of various dispersed and porous elements of the feathers into larger droplets leads to the volume reduction. Moreover, this work presents characteristics of the composition of the solid, liquid and gaseous products of turkey feathers pyrolysis at different temperatures. The higher heating value (HHV) of gaseous products in temperature 900°C equals 19.28 MJ/Nm(3) making the gases suitable for use as a fuel. The thermochemical conversion of turkey feathers leads to the formation of poisonous compounds such as hydrogen cyanide (HCN) in the liquid (0.13%) and gaseous (88 mg/Nm(3)) products. The phenomenon of liquefaction of feathers is important because it can lead to rapid degradation of the walls of reactors, and the formation of deposits. PMID:26783100

  18. Nanocrystalline Pt-doped TiO2 thin films prepared by spray pyrolysis for hydrogen gas detection

    Indian Academy of Sciences (India)

    Lalchand A Patil; Dinesh N Suryawanshi; Idris G Pathan; Dhanashri G Patil

    2014-05-01

    Nanostructured pure and Pt-doped TiO2 thin films were prepared by chemical spray pyrolysis technique. Aqueous solution of TiCl3.6H2O (0.01 M) was chosen as the starting solution for the preparation of pure TiO2 thin film. Aqueous solutions of PtCl6.6H2O (0.01 M) and TiCl3.6H2O (0.01 M) were mixed in volume % of 1 : 99, 2.5 : 97.5 and 5 : 95 respectively to obtain Pt-doped TiO2 thin films. The solutions were sprayed onto quartz substrate heated at 350 °C temperature to obtain the films. These thin films were fired for one hour at 550 °C. The sensing performance of these films was tested for various gases such as LPG, H2, CO2, ethanol, NH3 and Cl2 (1000 ppm). The Pt-doped TiO2 (1 : 99) was observed to be most sensitive (572) to H2 at 400 °C with high selectivity against other gases. Its response time was short (10 s) and recovery was also fast (14 s). To understand the reasons behind the gas-sensing performance of the films, their structural and micro-structral properties were studied using X-ray diffraction and electron microscopy (FE–SEM and TEM), respectively. Thicknesses of all these samples were determined using Surface Profiler. The results are interpreted.

  19. Segregation of Cu-In-S Elements in the Spray-Pyrolysis-Deposited Layer of CIS Solar Cells

    OpenAIRE

    Seigo Ito; Toshihiro Ryo

    2012-01-01

    We report the fabrication of superstrate-structured solar cells by the deposition of Cu-In-S (CIS) films on 〈glass/FTO/TiO2/In2S3〉 under air by spray pyrolysis. The cells had an open-circuit voltage of 0.551 V, a photocurrent density of 9.5 mA/cm2, a fill factor of 0.45, and a conversion efficiency of 2.14%. However, transmission electron microscopy/energy dispersive X-ray (TEM-EDX) analysis revealed significant differences between the atomic ratio of the setting material in the spray-deposit...

  20. Effect of annealing on the electrical, optical and structural properties of cadmium stannate thin films prepared by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Polycrystalline thin films of cadmium stannate (Cd2SnO4) were deposited by spray pyrolysis method on the Corning substrates at substrate temperature of 525 oC. Further, the films were annealed at 600 oC in vacuum for 30 min. These films were characterized for their structural, electrical and optical properties. The experimental results showed that the post-deposition annealing in vacuum has a significant influence on the properties of the films. The average grain size of the film was increased from 27.3 to 35.0 nm on heat treatment. The average optical transmittance in the visible region (500-850 nm) is decreased from 81.4% to 73.4% after annealing in vacuum. The minimum resistivity achieved in the present study for the vacuum annealed films is the lowest among the reported values for the Cd2SnO4 thin films prepared by spray pyrolysis method.

  1. Structural changes in ZrOxNy/ZrO2 coatings deposited through spray pyrolysis-nitriding

    International Nuclear Information System (INIS)

    Thin films of zirconium oxynitride were deposited on stainless steel 316l and characterized through ultrasonic spray pyrolysis-nitriding (Ups-N). Initially, thin films of ZrO2 are deposited using ultrasonic spray pyrolysis, and later ZrO2 films were nitrided in a NH3 atmosphere. We analyzed the effect of some variables, such as substrate temperature, flow ratio, and time of the production of coatings and their influence on the structure of the films. The characterization was carried out using X-ray diffraction (XRD) spectroscopy, X-ray photoelectron (XP S) and scanning electron microscopy (Sem). Films that were grown using the Ups method exhibited a tetragonal zirconia polycrystalline structure with preferential orientation in plane. These films, after being nitrided in an atmosphere of anhydrous ammonia at 1023 K, go through two processes: a phase transition from tetragonal to monoclinic, and later the formation of zirconium oxynitride rhombohedral ZrOxNy. (Author)

  2. Layer-by-layer deposition of superconducting Sr-Ca-Cu-O films by the spray pyrolysis technique

    International Nuclear Information System (INIS)

    Layer-by-layer deposition of Sr-Ca-Cu-O films has been carried out using the spray pyrolysis technique. Reagent-grade nitrates of strontium, calcium and copper were used to prepare starting solutions for spray pyrolysis. A two-step procedure was used for every layer of the constituents in the sequence Sr-Cu-Ca-Cu-Sr: first, deposition onto silver substrate at 350 C, then firing at T≥450 C, both at atmospheric pressure. The films were 2-3 μm thick and showed adequate adhesion to the substrate. The films were then characterised by studying their electron micrographs, X-ray diffraction patterns and electrical resistivity. The films showed superconductivity below 104 K. ((orig.))

  3. Thickness-Dependent Structural and Optoelectronic Properties of In2O3 Films Prepared by Spray Pyrolysis Technique

    Science.gov (United States)

    Khan, M. A. Majeed; Khan, Wasi

    2016-08-01

    In this work, nanostructured In2O3 thin films with thickness in the range of 40-160 nm were deposited on glass substrates by the chemical spray pyrolysis technique. The microstructural, surface morphology and optical properties were investigated as a function of film thickness through x-ray diffraction, scanning electron microscopy equipped with energy dispersive spectroscopy, atomic force microscopy, Raman spectroscopy, UV-visible spectroscopy and photoluminescence measurements. The x-ray diffraction analysis showed that the deposited films were polycrystalline in nature with a cubic structure having (222) as preferred orientation. The morphological analyses of the samples exhibited uniform and smooth surface of the films with systematical increments in the surface roughness with increasing film thickness. The grain size increased from 9 nm to 13 nm with increasing film thickness. Raman spectroscopy has been employed to study the crystalline quality and the structural disorder of the films. A blue-shift in the energy band gap ( E g) from 3.74 eV to 3.98 eV was observed with the increase of film thickness. Moreover, photoluminescence peaks of the In2O3 films appeared at 443 nm and 527 nm for all films. The thickness had a substantial influence on the microstructural and optical properties as well as on the luminescence intensity of the films. The strategy presented here indicates that the prepared films could be suitable candidates for optoelectronic device applications.

  4. Structural and Morphological Properties of Nanostructured ZnO Particles Grown by Ultrasonic Spray Pyrolysis Method with Horizontal Furnace

    Directory of Open Access Journals (Sweden)

    G. Flores-Carrasco

    2014-01-01

    Full Text Available ZnO nanoparticles were synthesized in a horizontal furnace at 500°C using different zinc nitrate hexahydrate concentrations (0.01 and 0.1 M as reactive solution by ultrasonic spray pyrolysis method. The physical-chemical properties of synthesized ZnO nanoparticles have been characterized by thermogravimetric analysis (TGA, X-ray diffraction (XRD, scanning electron microscopy (SEM, energy dispersive spectroscopy (EDS, and high resolution transmission electron microscopy (HRTEM. With the TGA is has optimized the temperature at which the initial reactive (Zn(NO32·6H2O, is decomposed completely to give way to its corresponding oxide, ZnO. SEM revealed secondary particles with a quasispherical shape that do not change significantly with the increasing of precursor solution concentration as well as some content of the broken spheres. Increasing the precursor solution concentration leads to the increase in the average size of ZnO secondary particles from 248±73 to 470±160 nm; XRD reveals the similar tendency for the crystallite size which changes from 23±4 to 45±4 nm. HRTEM implies that the secondary particles are with hierarchical structure composed of primary nanosized subunits. These results showed that the precursor concentration plays an important role in the evolution on the size, stoichiometry, and morphology of ZnO nanoparticles.

  5. Optical properties of undoped and tin-doped nanostructured In2O3 thin films deposited by spray pyrolysis

    Science.gov (United States)

    Fellahi, Nabil; Addou, Mohammed; Kachouane, Amina; El Jouad, Mohamed; Sofiani, Zouhair

    2016-05-01

    Tin-doped indium oxide (In2O3:Sn) thin films in different concentrations (Sn = 0, 3, 5, 8 at.%) were deposited by reactive chemical pulverisation spray pyrolysis on heated glass substrates at 500 °C. The effect of the tin dopant on the nonlinear optical properties was investigated using X-ray diffraction, transmission, electrical resistivity and third harmonic generation (THG). All films were polycrystalline, and crystallised in a cubic structure with a preferential orientation along the (400) direction. The Sn (5 at.%) doped In2O3 thin films exhibited a lower resistivity of 3 × 10-4 Ω cm, and higher transmission in the visible region of about 94%. Optical parameters, such as the extinction coefficient (k), refractive index (n) and energy band gap (Eg), were also studied to show the composition-dependence of tin-doped indium oxide films. The nonlinear properties of the In2O3:Sn thin films have been found to be influenced by doping concentration, and the best value of χ(3) = 3 × 10-11 (esu) was found for the 5 at.% doped sample. Contribution to the topical issue "Materials for Energy Harvesting, Conversion and Storage (ICOME 2015) - Elected submissions", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  6. Violet-blue luminescence from hafnium oxide layers doped with CeCl3 prepared by the spray pyrolysis process

    International Nuclear Information System (INIS)

    HfO2:CeCl3 coatings were deposited by the spray pyrolysis method employing hafnium dichloride oxide and CeCl3 dissolved in deionized water (18 MΩ/cm). The room temperature photoluminescence characteristics of the HfO2:CeCl3 films were studied as a function of the deposition parameters such as doping concentrations and substrate temperature. The presence of two different Ce3+ centres in HfO2 is detected from photoluminescence measurements. A reduction of the luminescence intensity is observed with an increase of both the CeCl3 concentration and the deposition temperature. X-ray diffraction measurements of these films showed that the crystalline structure depends on the substrate temperature. For substrate temperatures less than 350 C the deposited films are almost amorphous, while substrate temperatures higher than 400 C produce diffraction peaks corresponding to the monoclinic phase of HfO2. The chemical composition of the films as determined by energy dispersive spectroscopy is also reported. Furthermore, the surface morphology characteristics of the coatings, as a function of the deposition temperature, are also presented. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Synthesis of Li2Ti3O7 Anode Materials by Ultrasonic Spray Pyrolysis and Their Electrochemical Properties

    Directory of Open Access Journals (Sweden)

    Takayuki Kodera

    2013-06-01

    Full Text Available Ramsdellite-type lithium titanate (Li2Ti3O7 powders were synthesized by performing ultrasonic spray pyrolysis, and their chemical and physical properties were characterized by performing Scanning Electron Microscope (SEM, powder X-ray Diffraction (XRD, and Inductively Coupled Plasma (ICP analyses. The as-prepared Li2Ti3O7 precursor powders had spherical morphologies with hollow microstructures, but an irregularly shaped morphology was obtained after calcination above 900 °C. The ramsdellite Li2Ti3O7 crystal phase was obtained after the calcination at 1100 °C under an argon/hydrogen atmosphere. The first rechargeable capacity of the Li2Ti3O7 anode material was 168 mAh/g at 0.1 C and 82 mAh/g at 20 C, and the discharge capacity retention ratio was 99% at 1 C after the 500th cycle. The cycle performance of the Li2Ti3O7 anode was also highly stable at 50 °C, demonstrating the superiority of Li2Ti3O7 anode materials reported previously.

  8. Structure, optical and electrical properties of indium tin oxide ultra thin films prepared by jet nebulizer spray pyrolysis technique

    Directory of Open Access Journals (Sweden)

    M. Thirumoorthi

    2016-03-01

    Full Text Available Indium tin oxide (ITO thin films have been prepared by jet nebulizer spray pyrolysis technique for different Sn concentrations on glass substrates. X-ray diffraction patterns reveal that all the films are polycrystalline of cubic structure with preferentially oriented along (222 plane. SEM images show that films exhibit uniform surface morphology with well-defined spherical particles. The EDX spectrum confirms the presence of In, Sn and O elements in prepared films. AFM result indicates that the surface roughness of the films is reduced as Sn doping. The optical transmittance of ITO thin films is improved from 77% to 87% in visible region and optical band gap is increased from 3.59 to 4.07 eV. Photoluminescence spectra show mainly three emissions peaks (UV, blue and green and a shift observed in UV emission peak. The presence of functional groups and chemical bonding was analyzed by FTIR. Hall effect measurements show prepared films having n-type conductivity with low resistivity (3.9 × 10−4 Ω-cm and high carrier concentrations (6.1 × 1020 cm−3.

  9. One-step synthesis of bismuth molybdate catalysts via flame spray pyrolysis for the selective oxidation of propylene to acrolein

    DEFF Research Database (Denmark)

    Schuh, K.; Kleist, W.; Høj, Martin;

    2014-01-01

    Flame spray pyrolysis (FSP) of Bi(III)-and Mo(VI)-2-ethylhexanoate dissolved in xylene resulted in various nanocrystalline bismuth molybdate phases depending on the Bi/Mo ratio. Besides alpha-Bi2Mo3O12 and gamma-Bi2MoO6, FSP gave direct access to the metastable beta-Bi2Mo2O9 phase with high surface...

  10. Synthesis and Characterization of Earth Abundant and Nontoxic Metal Chalcogenides Produced via Aerosol Spray Pyrolysis for Photovoltaic Applications

    OpenAIRE

    Davis, Patrick John

    2013-01-01

    A novel synthesis technique for the production of copper zinc tin sulfide (CZTS) nanocrystals has been developed using aerosol spray pyrolysis. CZTS is a quaternary semiconducting material that shows promise as a replacement to common semiconductors such as CdTe and CIGS for use in photovoltaic devices. CIGS is currently being commercialized in the photovoltaic industry, but rare and expensive indium and gallium components threaten its long term viability. CZTS looks to be one of the best alt...

  11. Photocatalytic Activities of Copper Doped Cadmium Sulfide Microspheres Prepared by a Facile Ultrasonic Spray-Pyrolysis Method

    OpenAIRE

    Jinzhan Su; Tao Zhang; Yufeng Li; Yubin Chen; Maochang Liu

    2016-01-01

    Ultrasonic spray pyrolysis is a superior method for preparing and synthesizing spherical particles of metal oxide or sulfide semiconductors. Cadmium sulfide (CdS) photocatalysts with different sizes and doped-CdS with different dopants and doping levels have been synthesized to study their properties of photocatalytic hydrogen production from water. The CdS photocatalysts were characterized with scanning electron microscopy (SEM), X-ray fluorescence-spectrometry (XRF), UV-Vis absorption spect...

  12. Influence of the process parameters on the spray pyrolysis technique, on the synthesis of gadolinium doped-ceria thin film

    International Nuclear Information System (INIS)

    Graphical abstract: Gas-tight CGO made by spray pyrolysis suitable to be used as SOFC electrolyte. Display Omitted Highlights: ► Dense and crystalline CGO films deposited by spray pyrolysis on various substrates. ► Solvent did not have a strong influence on the film microstructure, defect concentration or thickness. ► The substrate did not have a strong influence on the film microstructure, defect concentration or thickness. ► Films with at least 2.5 μm of thickness presented high impermeability. ► The films obtained are suitable to use as a SOFC electrolyte. -- Abstract: This work presents the results of a process of optimization applied to gadolinia-doped ceria (Ce0.8Gd0.2O1.9−x, or CGO) thin films, deposited by spray pyrolysis (SP). Spray pyrolysis is a high thermal deposition method that combines material deposition and heat treatment. This combination is advantageous since the post-deposition heat treatment step is not necessary. However, stresses are solidified in the coating during the deposition, which may lead to the initiation of a crack in the coating. The aim of this work was to achieve thin, dense, and continuous CGO coatings, which may be used as gas separation membranes and as a solid state electrochemical interfaces. Dense, flat, low-defect substrates such as silica slides, silicon mono crystal wafers, and porous substrates were used as substrates in this work. Cerium ammonium nitrate and gadolinium acetylacetonate were dissolved in ethanol and butyl carbitol to form a precursor solution that was sprayed on the heated substrates. Process parameters such as solvent composition, deposition rate and different heating regimes were analyzed. The microstructure was analyzed by secondary electron microscopy (SEM) and was found that thin, dense, and defect-free films could be produced on dense and porous substrates. The results obtained show that it is possible to obtain a CGO dense film deposited by spray pyrolysis. X-ray diffraction (XRD

  13. Chemical recycling of mixed waste plastics by selective pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Tatsumoto, K.; Meglen, R.; Evans, R. [National Renewable Energy Laboratory, Golden, CO (United States)

    1995-05-01

    The goal of this work is to use selective pyrolysis to produce high-value chemicals from waste plastics mixtures. Selectivity is achieved by exploiting differences in reaction rates, catalysis, and coreactants. Target wastes are molecular mixtures such as; blends or composites, or mixtures from manufactured products such as; carpets and post-consumer mixed-plastic wastes. The experimental approach has been to use small-scale experiments using molecular beam mass spectrometry (MBMS), which provides rapid analysis of reaction products and permits rapid screening of process parameters. Rapid screening experiments permit exploration of many potential waste stream applications for the selective pyrolysis process. After initial screening, small-scale, fixed-bed and fluidized-bed reactors are used to provide products for conventional chemical analysis, to determine material balances, and to test the concept under conditions that will be used at a larger scale. Computer assisted data interpretation and intelligent chemical processing are used to extract process-relevant information from these experiments. An important element of this project employs technoeconomic assessments and market analyses of durables, the availability of other wastes, and end-product uses to identify target applications that have the potential for economic success.

  14. Synthesis of TiO2 core/RuO2 shell particles using multistep ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • TiO2 core/RuO2 shell submicron-particles were prepared via a sequential spray pyrolysis. • Spherical particles have the mean particle diameters between 200 and 400 nm. • This method is promising for synthesis of core–shell and core–multishell materials. - Abstract: Spherical submicron-particles with TiO2 core–RuO2 shell structure have been synthesized by employing sequential ultrasonic spray pyrolysis. The particles have been investigated by X-ray powder diffraction, scanning electron microscopy and different transmission electron microscopy techniques. The quality of the core–shell structure of the particles has been confirmed by comparison of the experimental data with those generated on the basis of a hard sphere core–shell model. It has been found that the mixing of the Ru-containing aerosol with the TiO2 particle stream has a significant impact on the core–shell formation. The method introduced in this study can probably be applied for preparation of core–shell and core–multishell materials that are difficult to synthesize in a single step spray pyrolysis process

  15. Thermoelectric and photoconductivity properties of zinc oxide–tin oxide binary systems prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Zinc oxide–Tin oxide (ZnO–SnO) binary thin films were prepared on the glass substrates by spray pyrolysis method. The variation range of the molar ratio of x = [Sn]/[Zn] considered to be changed from 5% to 50%. The films characterized by using the X-ray diffraction (XRD) technique, UV–Vis–NIR spectroscopy, Hall effect, Seebeck effect, electrical and photoconductivity measurements. Using the scanning electron microscopy (SEM) and atomic force microscopy (AFM) images the morphology and roughness of the thin films surfaces were obtained, respectively. AFM micrographs indicate the decrease of roughness by increasing the dopant (Sn) concentration (x). XRD results describe the existence of the ZnO, SnO, SnO2, ZnSnO3 and Zn2SnO4 phases for various x values. The optical band gap and transmittance were obtained from UV–Vis–NIR spectroscopy results as a function of x. The results show a general band gap narrowing which occurs with the increasing of the Sn concentration which attributed to the structure and many body effects. Moreover, comparing to ZnO thin films, the remarkable decrease of the electrical conductivity and optical transparency were observed at the low x values. The conduction type was determined by the Hall effect and thermoelectric measurements. The Seebeck effect measurements show for ∆T ≤ 185 K, the electrons are the majority carriers, which replaced with the holes for ∆T > 185 K. Power factor quantity was measured as a function of the Sn concentration and temperature. Furthermore, the power factor determines the best x value for the optimal electrical properties. Photoconductivity property was also observed in all samples which weakened for x ≤ 30%, and increased for the higher x values. - Highlights: • Zinc oxide–tin oxide binary thin films prepared by spray pyrolysis method. • Creation of binary system for Sn concentration between 10–30%. • Thermoelectric and photoconductive properties are observed in ZnO–SnO thin films.

  16. Structural, electrical and optical properties of indium chloride doped ZnO films synthesized by Ultrasonic Spray Pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Zaleta-Alejandre, E., E-mail: ezaleta@fis.cinvestav.mx [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico); Camargo-Martinez, J.; Ramirez-Garibo, A. [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico); Perez-Arrieta, M.L. [Universidad Autonoma de Zacatecas, Unidad Academica de Fisica, Calzada Solidaridad esq. Paseo, La Bufa s/n, C.P. 98060, Zacatecas, Mexico (Mexico); Balderas-Xicohtencatl, R.; Rivera-Alvarez, Z. [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico); Aguilar-Frutis, M. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-IPN, Legaria 694, Col. Irrigacion, Del. Miguel Hidalgo, Mexico, D.F. (Mexico); Falcony, C. [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico)

    2012-12-01

    Indium chloride doped zinc oxide (ZnO:In) thin films were deposited onto glass substrates using zinc acetate by Ultrasonic Spray Pyrolysis technique. The effect of substrate temperature, deposition time and acetic acid added to the spraying solution on the structural, electrical and optical properties of these ZnO:In films is reported. The films were in all cases polycrystalline with a hexagonal (wurtzite) structure, a transparency over 80% and resistivity of the order of 10{sup -3}-10{sup -2} Ohm-Sign {center_dot}cm. The resistivity was dependent on the volume % of acetic acid added to the spraying solution. The minimum resistivity value was obtained with a 5 vol.% acetic acid (pH = 3.71) at substrate temperature of 450 Degree-Sign C. The deposition rates obtained were as high as 180 A{center_dot}min{sup -1} at a substrate temperature of 450 Degree-Sign C. - Highlights: Black-Right-Pointing-Pointer Conductive ZnO:In thin films were deposited by Ultrasonic Spray Pyrolysis (USP). Black-Right-Pointing-Pointer USP is of low cost, high growth rates and scalable for industrial applications. Black-Right-Pointing-Pointer USP is appropriate for the deposition of metallic oxide films. Black-Right-Pointing-Pointer We studied the effect of acetic acid, time deposition and substrate temperature. Black-Right-Pointing-Pointer Zinc acetate and indium chloride were used as precursor materials.

  17. Structural, electrical and optical properties of indium chloride doped ZnO films synthesized by Ultrasonic Spray Pyrolysis technique

    International Nuclear Information System (INIS)

    Indium chloride doped zinc oxide (ZnO:In) thin films were deposited onto glass substrates using zinc acetate by Ultrasonic Spray Pyrolysis technique. The effect of substrate temperature, deposition time and acetic acid added to the spraying solution on the structural, electrical and optical properties of these ZnO:In films is reported. The films were in all cases polycrystalline with a hexagonal (wurtzite) structure, a transparency over 80% and resistivity of the order of 10−3–10−2 Ω·cm. The resistivity was dependent on the volume % of acetic acid added to the spraying solution. The minimum resistivity value was obtained with a 5 vol.% acetic acid (pH = 3.71) at substrate temperature of 450 °C. The deposition rates obtained were as high as 180 Å·min−1 at a substrate temperature of 450 °C. - Highlights: ► Conductive ZnO:In thin films were deposited by Ultrasonic Spray Pyrolysis (USP). ► USP is of low cost, high growth rates and scalable for industrial applications. ► USP is appropriate for the deposition of metallic oxide films. ► We studied the effect of acetic acid, time deposition and substrate temperature. ► Zinc acetate and indium chloride were used as precursor materials.

  18. Synthesis of nanocrystalline Cu2ZnSnS4 thin films grown by the spray-pyrolysis technique

    International Nuclear Information System (INIS)

    Spray pyrolysis was used to deposit Cu2ZnSnS4 (CZTS) thin films on soda lime glass substrates at 300 °C. Aqueous solutions of copper chloride, zinc chloride, stannous chloride and thiourea were mixed together to form the spray liquid. The sprayed films were annealed under vacuum at 350 °C, 400 °C and 450 °C. Structural and optical characterization was performed on the CZTS films using X-ray diffraction (XRD) and UV-VIS spectrophotometry. XRD results indicate that the films are single phase nanocrystalline CZTS. Optical studies show that the optical gap values are 1.44 eV for the as-grown film and 1.46 eV, 1.48 eV and 1.49 eV for the films annealed at 350 °C, 400 °C and 450 °C, respectively

  19. Size controlled synthesis of ZnO nanoparticles via electric field assisted continuous spray pyrolysis (EACoSP) reactor

    Energy Technology Data Exchange (ETDEWEB)

    Dwivedi, Charu; Dutta, V. [Indian Institute of Technology Delhi, Photovoltaic Laboratory, Centre for Energy Studies, New Delhi (India)

    2012-10-15

    ZnO nanoparticles were synthesized by the continuous spray pyrolysis technique (CoSP) and the effect of applied voltage across the spray nozzle and an annular ground electrode during spray has been studied. X-ray diffraction and transmission electron microscopy studies showed that the product has (hexagonal) wurtzite structure with the average particle size decreasing from 18.5 nm to 12.9 nm in the presence of a high DC voltage (1 kV). The higher value of the absorption peak for the nanoparticles synthesized without voltage is supportive of this behavior. The films deposited by spin coating using these nanoparticles can be used for a variety of applications, particularly as photoelectrodes for dye-sensitized solar cells. (orig.)

  20. Synthesis of nanocrystalline Cu2ZnSnS4 thin films grown by the spray-pyrolysis technique

    Science.gov (United States)

    Chandel, Tarun; Singh, Joginder; Rajaram, P.

    2015-08-01

    Spray pyrolysis was used to deposit Cu2ZnSnS4 (CZTS) thin films on soda lime glass substrates at 300 °C. Aqueous solutions of copper chloride, zinc chloride, stannous chloride and thiourea were mixed together to form the spray liquid. The sprayed films were annealed under vacuum at 350 °C, 400 °C and 450 °C. Structural and optical characterization was performed on the CZTS films using X-ray diffraction (XRD) and UV-VIS spectrophotometry. XRD results indicate that the films are single phase nanocrystalline CZTS. Optical studies show that the optical gap values are 1.44 eV for the as-grown film and 1.46 eV, 1.48 eV and 1.49 eV for the films annealed at 350 °C, 400 °C and 450 °C, respectively.

  1. Photocatalytic zinc oxide thin films obtained by surfactant assisted spray pyrolysis deposition

    International Nuclear Information System (INIS)

    Zinc oxide thin films were obtained by spray pyrolysis deposition using three surfactants with linear C12 tails as soft templating agents: anionic sodium dodecylsulfate (SDS), cationic dodecyltrimethylammonium bromide (DTAB) and nonionic dodecanol (DD). The influence of the surfactants’ type and concentration (above and below critical micelle concentration in the precursor system) on the thin film formation was investigated and was correlated with their photocatalytic efficiency in methylorange removal, under visible and UV iradiation. The surfactants influence both the nucleation and growth stages, mainly through the Zn-surfactant interactions at the droplet border and/or on the micelles. In situ doping with Na+ (in SDS) improves the removal efficiency up to 19.88% under VIS irradiation, while the highest removal efficiencies in ZnO thin films obtained using DTAB and DD are 16.27% and 15.44%, respectively. Under UV irradiation the highest efficiencies are 45.28% (SDS), 51.59% (DTAB) and 49.43% (DD).

  2. Heavy lithium-doped ZnO thin films prepared by spray pyrolysis method

    Indian Academy of Sciences (India)

    M Ardyanian; N Sedigh

    2014-10-01

    Lithium-doped ZnO thin films (ZnO : Li) were prepared by spray pyrolysis method on the glass substrates for ( = [Li]/[Zn]) value varied between 5 and 70%. Structural, electrical and optical properties of the samples were studied by X-ray diffraction (XRD), UV–Vis–NIR spectroscopy, scanning electron microscopy (SEM), Hall effect and sheet resistance measurements. XRD results show that for ≤ 50%, the structure of the films tends to be polycrystals of wurtzite structure with preferred direction along (0 0 2). The best crystalline order is found at = 20% and the crystal structure is stable until = 60%. The Hall effect results describe that Li doping leads to change in the conduction type from - to -type, again it changes to -type at = 70% and is attributed to self-compensation effect. Moreover, the carrier density was calculated in the order of 1013 cm-3. The resistivity of Li-doped films decreases until 22 cm at = 50%. Optical bandgap was reduced slightly, from 3.27 to 3.24 eV as a function of the grain size. Optical transmittance in the visible range reaches = 97%, by increasing of Li content until = 20%. Electrical and optical properties are coherent with structural results.

  3. Emission of ZnO:Ag nanorods obtained by ultrasonic spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Velázquez Lozada, E., E-mail: evlozada5@yahoo.com.mx [ESIME – Instituto Politécnico Nacional, México D.F. 07738 (Mexico); Torchynska, T.V.; Casas Espinola, J.L. [ESFM – Instituto Politécnico Nacional, México D.F. 07738 (Mexico); Pérez Millan, B. [UPIITA – Instituto Politécnico Nacional, México D.F. 07738 (Mexico)

    2014-11-15

    Scanning electronic microscopy (SEM), X ray diffraction (XRD), photoluminescence (PL) and its temperature dependence have been studied in ZnO:Ag nanorods (NRs) prepared by the ultrasonic spray pyrolysis (USP) method. The time variation at the growth of ZnO:Ag films permits modifying the ZnO phase from the amorphous to crystalline, to change the size of ZnO:Ag NRs and to vary their emission spectra. PL spectra of ZnO:Ag NRs versus temperature has been investigated. This study reveals that the PL band related to the acceptor Ag{sub Zn} (LO phonon replicas of an acceptor bound exciton, ABE (2.877 eV)), and its second-order diffraction peak (1.44 eV) disappeared in the temperature range of 10–170 K with the formation of free exciton (FX). The PL intensity of defect related PL bands decreases monotonously in the range 10–300 K with the activation energy of 13 meV. The PL band (3.22 eV), related to the LO phonon replica of free exciton (FX-2LO) and its second-order diffraction peak (1.61 eV) increase monotonously in the range 10–300 K. FX related peak dominates in PL spectra at room temperature that testifies on the high quality of ZnO:Ag films prepared by the USP technology.

  4. Preparation and characterization of iron oxide thin films by spray pyrolysis using methanolic and ethanolic solutions

    International Nuclear Information System (INIS)

    Iron oxide thin films have been obtained by spray pyrolysis using 100% methanolic and ethanolic solutions of iron tri-chloride. The films were deposited onto ITO-coated glass substrates. The preparative conditions have been optimized to obtain compact, pin-hole-free and smooth thin films which are adherent to the substrate. The structural, morphological and compositional characterizations have been carried out by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. The films deposited using ethanolic solution results into pure hematite; α-Fe2O3 thin films, however, films deposited using methanolic solution consists of hematite and maghemite-c phases of iron oxide. The films are nanocrystalline with particle size of 30-40 nm. The optical absorbance of the film was of the order of 105 cm-1. The optical band gap of films was found to be 2.26 and 2.20 eV for the films deposited using methanolic and ethanolic solutions, respectively

  5. Nano-sized ceria particles prepared by spray pyrolysis using polymeric precursor solution

    International Nuclear Information System (INIS)

    Nano-sized ceria particles were prepared from the aqueous solution containing the polymeric precursors by ultrasonic spray pyrolysis at the severe preparation conditions such as high flow rate of carrier gas and short residence time. The key idea to produce nanoparticles was to prepare hollow ceria particles which are easily turned to aggregates of nano-sized primary particles during the post-thermal treatment and thereafter disintegrate such aggregates to nano-sized particles by a simple ball milling process. It was found that using the polymeric precursor strongly influences the crystallization characteristics and morphological changes of the as-prepared particles during the post-thermal treatment. The as-prepared particles prepared from the polymeric precursor solution had non-spherical shape and fractured structure with a thin shell, whereas the as-prepared and calcined ceria particles obtained from the aqueous solution had spherical shape and hollow morphology with a thick shell. Also, nano-sized ceria particles prepared from the polymeric precursor solution had less aggregated structure than those prepared from the aqueous solution. For the ceria particles prepared from the polymeric precursor solution, the degree of aggregation between the primary particles was reduced as increasing the calcination temperature. As a result, aggregation-free nano-sized ceria particles were obtained above 1200 deg. C without a milling process. The mean size of the primary particles increased from several tens nanometer to submicrometer size as the calcination temperature changed from 800 to 1300 deg. C

  6. Photocatalytic studies of Ag/ZnO nanocomposite particles produced via ultrasonic spray pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Dermenci, Kamil Burak [Dept. of Materials Science and Engineering, Anadolu University, Eskisehir (Turkey); Dept. of Metallurgical and Materials Engineering, Istanbul Technical University, Istanbul (Turkey); Genc, Bora [Dept. of Environmental Engineering, Istanbul Technical University, Istanbul (Turkey); Ebin, Burçak [Dept. of Metallurgical and Materials Engineering, Istanbul Technical University, Istanbul (Turkey); Olmez-Hanci, Tugba [Dept. of Environmental Engineering, Istanbul Technical University, Istanbul (Turkey); Gürmen, Sebahattin, E-mail: gurmen@itu.edu.tr [Dept. of Metallurgical and Materials Engineering, Istanbul Technical University, Istanbul (Turkey)

    2014-02-15

    Highlights: • Ag/ZnO nanocomposite catalyst with a single step route is synthesized. • Methylene Blue decolorization, degradation and first order kinetics is studied. • The highest decolorization and degradation rates are 40% and 27% respectively. • The highest degradation rate coefficient is 9 × 10{sup −3} min{sup −1}. • Crystallite sizes and atomic fraction difference are important parameters. -- Abstract: Noble metal/semiconductor oxide nanocomposites have considerable interest on degradation of pollutants from textile wastewaters. Ag/ZnO, as one of the noble metal/semiconductor oxide nanocomposite, is highly efficient catalyst in textile pollutant degradation that allows irradiation wavelength towards visible light region. Ultrasonic spray pyrolysis method was used to produce spherical, homogenously distributed and submicron Ag/ZnO nanocomposite particles in one step. A water leach solution (0.05–0.2 M, Ag{sup +}:Zn{sup 2+} = 1:1) is carried by non-cost air into the reaction furnace (T = 700 °C, 800 °C and 900 °C). UV-A illumination of Methylene Blue (MB) with the presence of Ag/ZnO nanocatalysts after 60 min results up to 40% MB decolorization, 9 × 10{sup −3} min{sup −1} decolorization rate constant.

  7. Conductivity study of nitrogen-doped calcium zinc oxide prepared by spray pyrolysis

    Science.gov (United States)

    Hsu, Yu-Ting; Lan, Wen-How; Huang, Kai-Feng; Lin, Jia-Ching; Chang, Kuo-Jen

    2016-01-01

    In this study, the spray pyrolysis method was used to prepare unintentionally doped and nitrogen-doped calcium zinc oxide films by using zinc acetate, calcium nitrate precursor, and ammonium acetate precursor. Morphological and structural analyses were conducted using scanning electron microscopy and X-ray diffraction. The results indicated that film grain size decreased as the nitrogen doping was increased. Both calcium oxide and zinc oxide structures were identified in the unintentionally doped calcium zinc oxide. When nitrogen doping was introduced, the film mainly exhibited a zinc oxide structure with preferred (002) and (101) orientations. The concentration and mobility were investigated using a Hall measurement system. P-type films with a mobility and concentration of 10.6 cm2 V-1 s-1 and 2.8×1017 cm-3, respectively, were obtained. Moreover, according to a temperature-dependent conductivity analysis, an acceptor state with activation energy 0.266 eV dominated the p-type conduction for the unintentionally doped calcium zinc oxide. By contrast, a grain boundary with a barrier height of 0.274-0.292 eV dominated the hole conduction for the nitrogen-doped calcium zinc oxide films.

  8. Photocatalytic studies of Ag/ZnO nanocomposite particles produced via ultrasonic spray pyrolysis method

    International Nuclear Information System (INIS)

    Highlights: • Ag/ZnO nanocomposite catalyst with a single step route is synthesized. • Methylene Blue decolorization, degradation and first order kinetics is studied. • The highest decolorization and degradation rates are 40% and 27% respectively. • The highest degradation rate coefficient is 9 × 10−3 min−1. • Crystallite sizes and atomic fraction difference are important parameters. -- Abstract: Noble metal/semiconductor oxide nanocomposites have considerable interest on degradation of pollutants from textile wastewaters. Ag/ZnO, as one of the noble metal/semiconductor oxide nanocomposite, is highly efficient catalyst in textile pollutant degradation that allows irradiation wavelength towards visible light region. Ultrasonic spray pyrolysis method was used to produce spherical, homogenously distributed and submicron Ag/ZnO nanocomposite particles in one step. A water leach solution (0.05–0.2 M, Ag+:Zn2+ = 1:1) is carried by non-cost air into the reaction furnace (T = 700 °C, 800 °C and 900 °C). UV-A illumination of Methylene Blue (MB) with the presence of Ag/ZnO nanocatalysts after 60 min results up to 40% MB decolorization, 9 × 10−3 min−1 decolorization rate constant

  9. The role of palladium in iron based Fischer-Tropsch catalysts prepared by flame spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Minnermann, M.; Zielasek, V.; Baeumer, M. [Bremen Univ. (DE). Inst. of Applied and Physical Chemistry (IAPC); Pokhrei, S.; Maedler, L. [Bremen Univ. (DE). Foundation Inst. of Materials Science (IWT); Thiel, K. [Fraunhofer Institute for Manufactoring Technology and Applied Materials Research, Bremen (Germany)

    2011-07-01

    Flame spray pyrolysis (FSP) is a novel technique for the fabrication of nanostructured catalysts with far-reaching options to control structure and composition even in cases where complex composites need to be prepared. In this study, we took advantage of this technique to synthesize highly dispersed pure and Pd-doped iron oxide nanoparticles and investigated them as Fischer-Tropsch (FT) catalysts. By systematically varying the Pd content over a large range from 0.1 wt % to 10 wt %, we were able to directly analyze the influence of the Pd content on activity and selectivity. In addition to catalytic measurements, the structure and composition of the particles were characterized before and after these measurements, using transmission electron microscopy, adsorption measurements, X-ray diffraction and EXAFS. The comparison revealed, on the one hand, that small Pd clusters (diameter: 1-2 nm) evolve from initially homogeneously distributed Pd and, on the other hand, that the iron oxide transforms into iron carbides depending on the Pd content. The presence of Pd influences the particle size in the pristine samples (8 - 11 nm), resulting in specific surface areas that increase as the Pd content increases. However, after activation and reaction the specific surface areas become similar due to partial agglomeration and sintering. In a fixed bed FT reaction test, enhanced FT activity was observed with increasing Pd content while the selectivity shifts to longer chain hydrocarbons, mainly paraffins. (orig.)

  10. Synthesis of Al2O3 thin films using laser assisted spray pyrolysis (LASP)

    Science.gov (United States)

    Dhonge, Baban P.; Mathews, Tom; Tripura Sundari, S.; Krishnan, R.; Balamurugan, A. K.; Kamruddin, M.; Subbarao, R. V.; Dash, S.; Tyagi, A. K.

    2013-01-01

    The present study reports the development of a laser assisted ultrasonic spray pyrolysis technique and synthesis of dense optical alumina films using the same. In this technique ultrasonically generated aerosols of aluminum acetylacetonate dissolved in ethanol and a laser beam (Nd:YAG, CW, 1064 nm) were fed coaxially and concurrently through a quartz tube on to a hot substrate mounted on an X-Y raster stage. At the laser focused spot the precursor underwent solvent evaporation and solute sublimation followed by precursor vapor decomposition giving rise to oxide coating, the substrate is rastered to get large surface area coating. The surface morphology revealed coalescence of particles with increase in laser power. The observed particle sizes were 17 nm for films synthesized without laser and 18, 21 and 25 nm for films made with laser at 25, 38 and 50 W, respectively. Refractive index of the films synthesized increased from 1.56 to 1.62 as the laser power increased from 0 to 50 W. The stoichiometry of films was studied using XPS and the increase in interfacial layer thickness with laser power was observed from dynamic SIMS depth profiling and ellipsometry.

  11. Emission of ZnO:Ag nanorods obtained by ultrasonic spray pyrolysis

    Science.gov (United States)

    Velázquez Lozada, E.; Torchynska, T. V.; Casas Espinola, J. L.; Pérez Millan, B.

    2014-11-01

    Scanning electronic microscopy (SEM), X ray diffraction (XRD), photoluminescence (PL) and its temperature dependence have been studied in ZnO:Ag nanorods (NRs) prepared by the ultrasonic spray pyrolysis (USP) method. The time variation at the growth of ZnO:Ag films permits modifying the ZnO phase from the amorphous to crystalline, to change the size of ZnO:Ag NRs and to vary their emission spectra. PL spectra of ZnO:Ag NRs versus temperature has been investigated. This study reveals that the PL band related to the acceptor AgZn (LO phonon replicas of an acceptor bound exciton, ABE (2.877 eV)), and its second-order diffraction peak (1.44 eV) disappeared in the temperature range of 10-170 K with the formation of free exciton (FX). The PL intensity of defect related PL bands decreases monotonously in the range 10-300 K with the activation energy of 13 meV. The PL band (3.22 eV), related to the LO phonon replica of free exciton (FX-2LO) and its second-order diffraction peak (1.61 eV) increase monotonously in the range 10-300 K. FX related peak dominates in PL spectra at room temperature that testifies on the high quality of ZnO:Ag films prepared by the USP technology.

  12. Development of Ag/WO3/ITO thin film memristor using spray pyrolysis method

    Science.gov (United States)

    Dongale, T. D.; Mohite, S. V.; Bagade, A. A.; Gaikwad, P. K.; Patil, P. S.; Kamat, R. K.; Rajpure, K. Y.

    2015-11-01

    The unique nonlinear relationship between charge and magnetic flux along with the pinched hysteresis loop in I- V plane provide memory with resistance combinations of attribute to Memristor which lead to their novel applications in non volatile memory, nonlinear dynamics, analog computations and neuromorphic biological systems etc. The present paper reports development of Ag/WO3/ITO thin film memristor device using spray pyrolysis method. The structural, morphological and electrical properties of the thin film memristor device are further characterized using x-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and semiconductor device analyzer. The memristor is simulated using linear dopent drift model to ascertain the theoretical and experimental conformations. For the simulation purpose, the width of doped region (w) limited to the interval [0, D] is considered as a state variable along with the window function characterized by the equation f ( x) = w (1 - w). The reported memristor device exhibits the symmetric pinched hysteresis loop in I- V plane within the low operating voltage (±1 V). [Figure not available: see fulltext.

  13. Photocatalytic activities of heterostructured TiO2-graphene porous microspheres prepared by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Highlights: • USP method is used to prepare TiO2-graphene porous microspheres. • XPS shows GO sheets in the composites has been reduced to graphene. • TiO2-graphene microspheres display a red-shifted absorption edge. • PL spectra indicate graphene can accept the photoexcited electrons from TiO2. • TiO2-graphene shows higher photocatalytic activity than TiO2 under solar light. -- Abstract: TiO2-graphene porous microspheres were prepared by ultrasonic spray pyrolysis (USP) of aqueous suspension of graphene oxide containing TiO2 nanoparticles (Degussa P25). The composite microspheres were characterized with SEM, XPS, photoluminescence, Raman and UV–Vis absorption spectra. TiO2-graphene porous microspheres displayed higher photocatalytic activity for the degradation of methylene blue solution than pristine TiO2 microspheres under the irradiation of Xe lamp, and the highest activity was obtained at a weight percentage of graphene around 1%. The effect of graphene on photocatalytic activity of porous microsphere was discussed in terms of the enhanced charge separation by TiO2-graphene heterojunction, increased absorption of the visible light, as well as the possible hindrance of mass transportation in microspheres

  14. Optical and electrical characterization of AgInS2 thin films deposited by spray pyrolysis

    International Nuclear Information System (INIS)

    Silver indium sulfide (AgInS2) thin films have been prepared by spray pyrolysis (SP) technique using silver acetate, indium acetate, and N, N-dimethylthiourea as precursor compounds. Films were deposited onto glass substrates at different substrate temperatures (Ts) and Ag:In:S ratios in the starting solutions. Optical transmission and reflection as well as electrical measurements were performed in order to study the effect of deposition parameters on the optical and electrical properties of AgInS2 thin films. X-ray diffraction measurements were used to identify the deposited compounds. It was found that different compounds such as AgInS2, Ag2S, In2O3, and In2S3 can be grown only by changing the Ag:In:S ratio in the starting solution and Ts. So that, by carefully selecting the deposition parameters, single phase AgInS2 thin films can be easily grown. Thin films obtained using a molar ratio of Ag:In:S = 1:1:2 and Ts = 400 oC, have an optical band gap of 1.9 eV and n-type electrical conductivity with a value of 0.3 Ω-1 cm-1 in the dark.

  15. Physical properties of transparent conducting zinc oxide films prepared by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Zinc oxide (ZnO) is a wide band gap semiconductor with wide application in thin film devices such as thin film solar cells, piezoelectric and luminescent devices. In this work, ZnO films were deposited by Ultrasonic Spray Pyrolysis (USP) at 350±5 #Celsius# substrate temperature and electrical, optical and structural properties of these films were investigated. The electrical resistivity of the films was calculated as 2.5x10''2 Ω.cm using two probe method. The energy gap was calculated as 3.34 eV using optical method and the average transmittance in the visible range was found to be about 80%. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive x-ray spectrometry (EDS) were used to study the crystal structure, surface morphology and elemental analysis of the films, respectively. X-ray diffraction patterns indicates that the crystallites of ZnO films was preferentially oriented along the c-axis, (002) direction of the hexagonal crystal structure. SEM microghraps showed that the surface morphology of the films was nearly homogeneous. Using EDS microanalysis, it was determined that Zn and O elements present in solid films

  16. Nitrogen-doped carbon nanotubes with tunable structure and high yield produced by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Nitrogen-doped carbon nanotubes (CNx) were prepared by ultrasonic spray pyrolysis from mixtures of imidazole and acetonitrile. Imidazole, as an additive, was used to control the structure and nitrogen doping in CNx by adjusting its concentration in the mixtures. Scanning electron microscopy observation showed that the addition of imidazole increased the nanotube growth rate and yield, while decreased the nanotube diameter. Transmission electron microscopy study indicated that the addition of imidazole promoted the formation of a dense bamboo-like structure in CNx. X-ray photoelectron spectroscopy analysis demonstrated that the nitrogen content varied from 3.2 to 5.2 at.% in CNx obtained with different imidazole concentrations. Raman spectra study showed that the intensity ratio of D to G bands gradually increased, while that of 2D to G bands decreased, due to increasing imidazole concentration. The yield of CNx made from mixtures of imidazole and acetonitrile can reach 192 mg in 24 min, which is 15 times that of CNx prepared from only acetonitrile. The aligned CNx, with controlled nitrogen doping, tunable structure and high yield, may find applications in developing non-noble catalysts and novel catalyst supports for fuel cells.

  17. Characterization of luminescent samarium doped HfO{sub 2} coatings synthesized by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Chacon-Roa, C [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-IPN, Legaria 694, Col. Irrigacion, C.P. 11500, Mexico D.F. (Mexico); Guzman-Mendoza, J [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-IPN, Legaria 694, Col. Irrigacion, C.P. 11500, Mexico D.F. (Mexico); Aguilar-Frutis, M [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-IPN, Legaria 694, Col. Irrigacion, C.P. 11500, Mexico D.F. (Mexico); Garcia-Hipolito, M [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, A.P. 70-360 Coyoacan 04510, Mexico, D.F. (Mexico); Alvarez-Fragoso, O [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, A.P. 70-360 Coyoacan 04510, Mexico, D.F. (Mexico); Falcony, C [Departamento de Fisica, CINVESTAV-IPN, A. P. 14-740, 07000 Mexico D.F. (Mexico)

    2008-01-07

    Trivalent samarium (Sm{sup 3+}) doped hafnium oxide (HfO{sub 2}) films were deposited using the spray pyrolysis deposition technique. The films were deposited on Corning glass substrates at temperatures ranging from 300 to 550 deg. C using chlorides as raw materials. Films, mostly amorphous, were obtained when deposition temperatures were below 350 deg. C. However, for temperatures higher than 400 deg. C, the films became polycrystalline, presenting the HfO{sub 2} monoclinic phase. Scanning electron microscopy of the films revealed a rough surface morphology with spherical particles. Also, electron energy dispersive analysis was performed on these films. The photoluminescence and cathodoluminescence characteristics of the HfO{sub 2} : SmCl{sub 3} films, measured at room temperature, exhibited four main bands centred at 570, 610, 652 and 716 nm, which are due to the well-known intra-4f transitions of the Sm{sup 3+} ion. It was found that the overall emission intensity rose as the deposition temperature was increased. Furthermore, a concentration quenching of the luminescence intensity was also observed.

  18. Characterization of luminescent samarium doped HfO2 coatings synthesized by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Trivalent samarium (Sm3+) doped hafnium oxide (HfO2) films were deposited using the spray pyrolysis deposition technique. The films were deposited on Corning glass substrates at temperatures ranging from 300 to 550 deg. C using chlorides as raw materials. Films, mostly amorphous, were obtained when deposition temperatures were below 350 deg. C. However, for temperatures higher than 400 deg. C, the films became polycrystalline, presenting the HfO2 monoclinic phase. Scanning electron microscopy of the films revealed a rough surface morphology with spherical particles. Also, electron energy dispersive analysis was performed on these films. The photoluminescence and cathodoluminescence characteristics of the HfO2 : SmCl3 films, measured at room temperature, exhibited four main bands centred at 570, 610, 652 and 716 nm, which are due to the well-known intra-4f transitions of the Sm3+ ion. It was found that the overall emission intensity rose as the deposition temperature was increased. Furthermore, a concentration quenching of the luminescence intensity was also observed

  19. Investigation on vanadium oxide thin films deposited by spray pyrolysis technique

    Science.gov (United States)

    Margoni, Mudaliar Mahesh; Mathuri, S.; Ramamurthi, K.; Babu, R. Ramesh; Sethuraman, K.

    2016-05-01

    Vanadium oxide thin films were deposited at 400 °C by spray pyrolysis technique using 0.1 M aqueous precursor solution of ammonium meta vanadate (AMV) with two different pH values. X-ray diffraction results showed that the film prepared using aqueous precursor AMV solution (solution A; pH 7) is amorphous in nature and the film prepared by adding HNO3 in the AMV aqua solution A (solution B; pH 3) is polycrystalline in nature. Vanadium oxide film prepared from the precursor solution B is in the mixed phases of V2O5 and V4O7. Crystallinity is improved for the film prepared using solution B when compared to film prepared from solution A. Crystallite size, strain and dislocation density calculated for the film prepared from solution B is respectively 72.1 nm, 0.4554 × 10-3 lin.-2m-4 and 1.7263 × 1014 lin.m-2. Morphology study revealed that the size of the flakes formed on the surface of the films is influenced by the pH of the precursor solution. Average Visible Transmittance and maximum transmittance of the deposited films exceed 70% and the direct optical band gap value calculated for the films deposited from A and B solution is 1.91 eV and 2.08 eV respectively.

  20. Evolution of Zinc Oxide Nanostructures Grown on Graphene by Ultrasonic Spray Pyrolysis and Its Statistical Growth Modelling.

    Science.gov (United States)

    Ali, Amgad Ahmed; Hashim, Abdul Manaf

    2015-12-01

    The evolution of zinc oxide nanostructures grown on graphene by alcohol-assisted ultrasonic spray pyrolysis was investigated. The evolution of structures is strongly depended on pyrolysis parameters, i.e., precursor molarity, precursor flow rate, precursor injection/deposition time, and substrate temperature. Field-effect scanning electron microscope analysis, energy dispersive X-ray spectroscopy, X-ray diffraction, and transmission electron microscopy were used to investigate the properties of the synthesized nanostructures and to provide evidence for the structural changes according to the changes in the pyrolysis parameters. The optimum parameters to achieve maximum density and well-defined hexagonally shaped nanorods were a precursor molarity of 0.2 M, an injection flow rate of 6 ml/min, an injection time of 10 min, and a substrate temperature of 250-355 °C. Based on the experimental results, the response surface methodology (RSM) was used to model and optimize the independent pyrolysis parameters using the Box-Behnken design. Here, the responses, i.e., the nanostructure density, size, and shape factor, are evaluated. All of the computations were performed using the Design-Expert software package. Analysis of variance (ANOVA) was used to evaluate the results of the model and to determine the significant values for the independent pyrolysis parameters. The evolution of zinc oxide (ZnO) structures are well explained by the developed modelling which confirms that RSM is a reliable tool for the modelling and optimization of the pyrolysis parameters and prediction of nanostructure sizes and shapes. PMID:26608535

  1. Ultrasonic spray pyrolysis growth of ZnO and ZnO:Al nanostructured films: Application to photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Kenanakis, G., E-mail: gkenanak@iesl.forth.gr [Institute of Electronic Structure and Laser, Foundation for Research and Technology – Hellas, P.O. Box 1385, Vassilika Vouton, 711 10 Heraklion, Crete (Greece); Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Katsarakis, N. [Institute of Electronic Structure and Laser, Foundation for Research and Technology – Hellas, P.O. Box 1385, Vassilika Vouton, 711 10 Heraklion, Crete (Greece); Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece)

    2014-12-15

    Highlights: • Al–ZnO thin films and nanostructures were obtained by ultrasonic spray pyrolysis. • The texture and morphology of the samples depend on the deposition parameters. • The photocatalytic degradation of stearic acid was studied upon UV-A irradiation. - Abstract: Pure and Al-doped ZnO (Al = 1, 3, 5%) nanostructured thin films were grown at 400 °C on glass substrates by ultrasonic spray pyrolysis, a simple, environmental-friendly and inexpensive method, using aqueous solutions as precursors. The structural and morphological characteristics of the samples depend drastically on deposition parameters; ZnO nanostructured films, nanopetals and nanorods were systematically obtained by simply varying the precursor solution and/or the spraying time. Transmittance measurements have shown that all samples are transparent in the visible wavelength region. Finally, the photocatalytic properties of the samples were investigated against the degradation of stearic acid under UV-A light illumination (365 nm); both pure and Al-doped ZnO nanostructured thin films show good photocatalytic activity regarding the degradation of stearic acid, due to their good crystallinity and large surface area.

  2. Ultrasonic spray pyrolysis growth of ZnO and ZnO:Al nanostructured films: Application to photocatalysis

    International Nuclear Information System (INIS)

    Highlights: • Al–ZnO thin films and nanostructures were obtained by ultrasonic spray pyrolysis. • The texture and morphology of the samples depend on the deposition parameters. • The photocatalytic degradation of stearic acid was studied upon UV-A irradiation. - Abstract: Pure and Al-doped ZnO (Al = 1, 3, 5%) nanostructured thin films were grown at 400 °C on glass substrates by ultrasonic spray pyrolysis, a simple, environmental-friendly and inexpensive method, using aqueous solutions as precursors. The structural and morphological characteristics of the samples depend drastically on deposition parameters; ZnO nanostructured films, nanopetals and nanorods were systematically obtained by simply varying the precursor solution and/or the spraying time. Transmittance measurements have shown that all samples are transparent in the visible wavelength region. Finally, the photocatalytic properties of the samples were investigated against the degradation of stearic acid under UV-A light illumination (365 nm); both pure and Al-doped ZnO nanostructured thin films show good photocatalytic activity regarding the degradation of stearic acid, due to their good crystallinity and large surface area

  3. Structural and optical properties of ZnO films produced by a modified ultrasonic spray pyrolysis technique

    International Nuclear Information System (INIS)

    In this work we present a modification of the usual ultrasonic spray pyrolysis method and tested its ability to produce good quality films by producing ZnO films. Our method consists of keeping the sprayed substrate at room temperature and, after that, a thermal treatment under a chosen environment and temperature is made. We used this method to produce ZnO films considering two environments, air and air + vapor of zinc acetate, and two temperatures, 400 °C and 450 °C. The ZnO films were investigated by X-ray diffraction, scanning electron microscopy, cathodoluminescence, thermogravimetry/simultaneum differential thermal analysis and Raman spectroscopy techniques, and results indicated that ZnO films produced under air + vapor of zinc acetate at 400 °C are the best films obtained by our modified method. - Highlights: • A variation of the ultrasonic spray pyrolysis (USP) technique is introduced. • ZnO films were produced using the modification of the USP technique. • High quality ZnO films were produced at a lower temperature than those used in other studies

  4. Influence of solution deposition rate on properties of V2O5 thin films deposited by spray pyrolysis technique

    Science.gov (United States)

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

    2016-07-01

    Vanadium oxide (V2O5) 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 VCl3 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 V2O5 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).

  5. Spray pyrolysis deposited zinc oxide films for photo-electrocatalytic degradation of methyl orange: influence of the pH

    International Nuclear Information System (INIS)

    Zinc oxide films were made by spray pyrolysis equipped with an optical system for in-situ thickness measurement; zinc acetate water solution was used as spraying solution. The pH of the spraying solution was modified in order to increase the film porosity. Morphology and structure of the films were analyzed by scanning electron microscopy and x-ray diffraction, respectively. X-ray pattern revealed that films were zincite-like with a preferential growth in the [002]-direction. The optical absorbance of the methyl orange aqueous solution and the optical transmittance of ZnO-based films were measured in the wavelength range of 350-800 nm. Those measurements allowed both to control the photo-electrocatalytic degradation of methyl orange and to correlate the optical measurements with surface morphology of ZnO-based films. The zinc oxide based films obtained at different pH conditions of the spraying solution were brought into contact with methyl orange aqueous solution in a reactor in which the photo-electrocatalytically induced degradation under ultraviolet irradiation was investigated; the reactor was provided by an optical system to measure the in-situ optical transmittance of methyl orange solution. Results indicated that there is an increment of the active area of ZnO thin films when the pH of the spraying solution increases. (authors)

  6. Deposition of Sn O2 thin films by spray-pyrolysis of Sn Cl2 water solution

    International Nuclear Information System (INIS)

    A modified spray-pyrolysis method was used in order to produce good quality transparent conductive Sn O2 thin films. The modification concerns the use of aqueous (water) solution of Sn Cl, complexed by HF and NH, sprayed onto heated glass substrate by electromagnetic sprayer. The composition and structure of deposited material was approved from the X-ray diffraction spectra, optical absorption spectra and microphotography. The optical absorption spectra showed direct band - to - band transition with a band gap of 2.7 eV. The thermal dependence of the resistivity and thermoelectric power showed metallic properties of deposited material. The dependence of the resistivity on the film thickness has shown diffusional scattering of the free carriers with a mean free path about 250 nm. It was found that the film quality (Haackier figure of merit) strongly depends on the concentration of the complex solution, the substrate temperature and spraying rate (the spray time and the pause between two successive spraying). (author)

  7. Characterization of luminescent praseodymium-doped ZrO{sub 2} coatings deposited by ultrasonic spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Brito, F [Laboratorio de Materiales Optoelectronicos, DiDe, Centro de Ciencias de Sinaloa, Av. De las Americas No. 2771 Nte. Col. Villa Universidad, C.P. 80010 Culiacan, Sinaloa (Mexico); Garcia-Hipolito, M [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, AP 70-360 Coyoacan 04510 DF (Mexico); Alejo-Armenta, C [Laboratorio de Materiales Optoelectronicos, DiDe, Centro de Ciencias de Sinaloa, Av. De las Americas No. 2771 Nte. Col. Villa Universidad, C.P. 80010 Culiacan, Sinaloa (Mexico); Alvarez-Fragoso, O [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, AP 70-360 Coyoacan 04510 DF (Mexico); Falcony, C [Departamento de Fisica, CINVESTAV-IPN, Apdo. Postal 14-740, 07000 DF (Mexico)

    2007-11-07

    ZrO{sub 2} : Pr films were synthesized by the ultrasonic spray pyrolysis process. X-ray diffraction studies, as a function of the deposition temperature, indicate a tetragonal crystal structure of zirconia as the substrate temperature was increased. Luminescence (photo- and cathodoluminescence) properties of the films were studied as a function of growth parameters such as the substrate temperature and the praseodymium concentration. For an excitation wavelength of 290 nm, all the photoluminescent emission spectra show peaks located at 490, 510, 566, 615, 642, 695, 718, 740 and 833 nm, associated with the electronic transitions {sup 3} P{sub 0} {yields} {sup 3}H{sub 4}, {sup 3}P{sub 0} {yields} {sup 3} H{sub 4}, {sup 3}P{sub 1} + {sup 1}I{sub 6} {yields} {sup 3}H{sub 5}, {sup 1}D{sub 2} {yields} {sup 3}H{sub 4}, {sup 3} P{sub 0} {yields} {sup 3}H{sub 6}, {sup 1}D{sub 2} {yields} {sup 3} H{sub 5}, {sup 1}D{sub 2} {yields} {sup 3}H{sub 5}, {sup 3} P{sub 0} {yields} {sup 3}F{sub 3,4} and {sup 1}D{sub 2} {yields} {sup 3} F{sub 2} of the Pr{sup 3+} ion. As the deposition temperature is increased, an increasing intensity of the luminescence emission is observed. Also, quenching of the luminescence, with increasing doping concentration, is observed. The chemical composition of the films as determined by energy dispersive spectroscopy is reported as well. In addition, the surface morphology characteristics of the films, as a function of the deposition temperature, are presented.

  8. Synthesis and characterization of Fe doped cadmium selenide thin films by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Abhijit A., E-mail: aay_physics@yahoo.co.in [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413 512, Maharashtra (India)

    2012-12-05

    Highlights: Black-Right-Pointing-Pointer Simple and inexpensive method to dope trivalent Fe in CdSe thin films. Black-Right-Pointing-Pointer Fe doped CdSe thin films are highly photosensitive. Black-Right-Pointing-Pointer AFM analysis shows uniform deposition of film over the entire substrate surface. Black-Right-Pointing-Pointer The band gap energy decreases from 1.74 to 1.65 eV with Fe doping. Black-Right-Pointing-Pointer Film resistivity decreases to 6.76 Multiplication-Sign 10{sup 4} {Omega}-cm with Fe doping in CdSe thin films. - Abstract: Undoped and Fe doped CdSe thin films have been deposited onto the amorphous and fluorine doped tin oxide coated glass substrates by spray pyrolysis. The Fe doping concentration has been optimized by photoelectrochemical (PEC) characterization technique. The structural, surface morphological, compositional, optical and electrical properties of undoped and Fe doped CdSe thin films have been studied. X-ray diffraction study reveals that the as deposited CdSe films possess hexagonal crystal structure with preferential orientation along (1 0 0) plane. AFM analysis shows uniform deposition of the film over the entire substrate surface with minimum surface roughness of 7.90 nm. Direct allowed type of transition with band gap decreasing from 1.74 to 1.65 eV with Fe doping has been observed. The activation energy of the films has been found to be in the range of 0.14-0.19 eV at low temperature and 0.27-0.44 eV at high temperature. Semi-conducting behavior has been observed from resistivity measurements. The thermoelectric power measurements reveal that the films are of n type.

  9. Morphological and electrochemical properties of LiV3O8 cathode powders prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Lithium trivanadate (LiV3O8) powders are prepared by spray pyrolysis. The precursor powders of LiV3O8 obtained by spray pyrolysis have spherical and rod-like morphologies. The LiV3O8 powders post-treated at 300 oC and 400 oC also have spherical and rod-like morphologies. However, the LiV3O8 cathode powders post-treated at 500 oC consist of only rod-like crystals. The crystalline structure of the precursor powders that were directly prepared by spray pyrolysis comprised of LiV3O8 layers along with a small amount of β-Li0.33V2O5 impurity. The peak due to β-Li0.33V2O5 persisted in the XRD spectrum even after post-treatment at 300 oC. On the other hand, crystalline structures of the powders post-treated at 400 oC and 500 oC comprised pure LiV3O8 layers. The initial discharge capacities of the LiV3O8 cathode powders decrease from 344 mAh g-1 to 261 mAh g-1 when the post-treatment temperatures increase from 300 oC to 500 oC. The discharge capacities of the LiV3O8 cathode powders obtained after post-treatment at 400 oC and 500 oC are approximately 255 mAh g-1 and 236 mAh g-1, respectively, after 40 cycles.

  10. Release mitigation spray safety systems for chemical demilitarization applications.

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Jonathan; Tezak, Matthew Stephen; Brockmann, John E.; Servantes, Brandon; Sanchez, Andres L.; Tucker, Mark David; Allen, Ashley N.; Wilson, Mollye C.; Lucero, Daniel A.; Betty, Rita G.

    2010-06-01

    Sandia National Laboratories has conducted proof-of-concept experiments demonstrating effective knockdown and neutralization of aerosolized CBW simulants using charged DF-200 decontaminant sprays. DF-200 is an aqueous decontaminant, developed by Sandia National Laboratories, and procured and fielded by the US Military. Of significance is the potential application of this fundamental technology to numerous applications including mitigation and neutralization of releases arising during chemical demilitarization operations. A release mitigation spray safety system will remove airborne contaminants from an accidental release during operations, to protect personnel and limit contamination. Sandia National Laboratories recently (November, 2008) secured funding from the US Army's Program Manager for Non-Stockpile Chemical Materials Agency (PMNSCMA) to investigate use of mitigation spray systems for chemical demilitarization applications. For non-stockpile processes, mitigation spray systems co-located with the current Explosive Destruction System (EDS) will provide security both as an operational protective measure and in the event of an accidental release. Additionally, 'tented' mitigation spray systems for native or foreign remediation and recovery operations will contain accidental releases arising from removal of underground, unstable CBW munitions. A mitigation spray system for highly controlled stockpile operations will provide defense from accidental spills or leaks during routine procedures.

  11. Preparation of spherical and dense LiNi0.8Co0.2O2 lithium-ion battery particles by spray pyrolysis

    Institute of Scientific and Technical Information of China (English)

    HU Guo-rong; DENG Xin-rong; PENG Zhong-dong; CAO Yan-bin; LIU Zhi-min; LIU Ye-xiang

    2008-01-01

    With citric acid as a polymeric agent layered LiNi0.8Co0.2O2 materials were synthesized by a spray pyrolysis method. TheLiNi0.8Co0.2O2 particles were characterized by means of XRD, SEM and TEM. The electrochemical performances of LiNi0.8Co0.2O2particles were studied in a voltage window of 3.00-4.35 V and at a current density of 30 mA/g. The results show that in the pilot-scale spray pyrolysis process, the morphology of particles is dependent upon the precursor concentration and flux of carrier gas. excellent cycleability after 30 cycles. The LiNi0.8Co0.2O2 samples synthesized under the optimized conditions by the spray pyrolysis method shows a good electrochemical performance.

  12. MgO thin films deposited by electrostatic spray pyrolysis for protecting layers in AC-plasma display panel

    CERN Document Server

    Kim, S G

    1999-01-01

    MgO thin films were deposited on SiO sub 2 (100) substrates by using electrostatic spray pyrolysis and Mg(tmhd) sub 2 as the precursor. The growth rates of the films varyed from 34 to 87 A/min and were measured for various substrate and guide temperatures. X-ray diffraction analysis provide evidence that the MgO films deposited at temperatures as low as 400 approx 500 .deg. C had preferred orientation to (100) plane perpendicular to the substrate surface. X-ray photoelectron spectroscopy and Auger electron spectroscopy data indicated that there were few organics incorporated in the films.

  13. Formation of self-assembled quantum dots of iron oxide thin films by spray pyrolysis from non-aqueous medium

    International Nuclear Information System (INIS)

    Quantum dots (QDs) of iron oxide have been deposited onto ITO coated glass substrates by spray pyrolysis technique, using ferric chloride (FeCl3.7H2O) in non-aqueous medium as a starting material. The non-aqueous solvents namely methanol, ethanol, propanol, butanol and pentanol were used as solvents. The effect of solvents on the film structure and morphology was studied. The structural, morphological, compositional and optical properties were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), and optical absorption measurement techniques

  14. Synthesis of Core-Shell SiOx/Carbon Nano fibers on Silicon Substrates by Ultrasonic Spray Pyrolysis

    International Nuclear Information System (INIS)

    We synthesized the core-shell SiOx/carbon nano fibers with diameters of 200-300 nm using ultrasonic spray pyrolysis with a phosphorus/ethanol mixture. High-resolution transmission electron microscopy (HRTEM) and energy-dispersive spectroscopy (EDS) investigations confirmed the core-shell structure, which consisted of a core of SiOx and a shell of amorphous carbon. The phosphorus atoms corroded the entire silicon substrate surface, and the Si-P liquid-catalyzed the solid-liquid-solid mechanism is proposed to explain the growth of the core-shell SiOx/carbon nano fibers.

  15. Synthesis and Electrochemical Properties of Al doped Lithium Manganate Powders by Spray Pyrolysis Using Carbonate Aqueous Solution

    OpenAIRE

    HIROSE, Shoji; KODERA, Takayuki; Ogihara, Takashi

    2011-01-01

    Al doped LiMn2O4 powders were prepared by spray pyrolysis using the aqueous solution ofmanganese carbonate. The aqueous solution, in which manganese carbonate was uniformly dispersedby a surfactant, was used as the starting solution. Al2O3 nanopowders, Al(OH)3 and Al(NO3)3·9H2Owere used as the doping agent of Al. A scanning electron microscope photograph showed that Aldoped LiMn2O4 powders had spherical morphology with broad particle size distribution. X-raydiffraction revealed that crystal p...

  16. Preparation of nanostructured ZrO2 thin films by using spray pyrolysis technique for gas sensing application

    International Nuclear Information System (INIS)

    In present work the nano-structured pure ZrO2 thin films were prepared using spray pyrolysis techniques. The aqueous solution of ZrCl4, was used as a precursor with flow rate controlled 5 mI/min. The films were synthesized on glass substrate between temperature 250-400℃ and subjected to different analytical characterization like SEM, XRD, TEM, FTIR, UV, TGA-DTA/DSC. The gas sensing performances of various gases were tested in different operating temperature range. The sensitivity, selectivity, response and recovery time for H2S gas was discussed. Also nano structured grain size discussed. (author)

  17. Temperature dependent grain-size and microstrain of CdO thin films prepared by spray pyrolysis method

    Indian Academy of Sciences (India)

    B G Jeyaprakash; K Kesavan; R Ashok Kumar; S Mohan; A Amalarani

    2011-07-01

    CdO thin films on glass substrate were prepared by home built spray pyrolysis unit from aqueous solution of Cd(CH3COO)2.2H2O at different substrate temperatures. X-ray diffraction (XRD) studies indicate the formation of polycrystalline cubic CdO phase with preferential orientation along (111) plane. X-ray line broadening technique is adopted to study the effect of substrate temperature on microstructural parameters such as grain size and microstrain. Scanning electron microscopy (SEM) shows that the film prepared at 250°C consists of spherical shape grains with size in nanometer range and is comparable with the XRD studies.

  18. Effect of Annealing Temperature on the Performance of SnO2 Thin Film Transistors Prepared by Spray Pyrolysis.

    Science.gov (United States)

    Zhang, XinAn; Zhai, JunXia; Yu, XianKun; Zhu, RuiJuan; Zhang, WeiFeng

    2015-08-01

    We fabricated SnO2 thin film transistors on thermally oxidized p-type silicon substrates by low-cost spray pyrolysis. The effect of annealing temperatures on electrical characteristics of SnO2 thin film transistors were investigated. Thermal annealing at higher temperatures induced a negative shift of the threshold voltage (VT) and an increase in the saturation mobility. It was found that the device annealed at 450 °C exhibited a good electrical performance with the field-effect mobility of 0.19 cm2/Vs, the threshold voltage of 2.5 V, and the on/off current ratio of 10(3). PMID:26369222

  19. Effect of the precursor solution concentration on the NiO thin film properties deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Reguig, B.A.; Khelil, A. [LPCM2E, Universite d' Oran Es Senia (Algerie); Regragui, M.; Morsli, M.; Bernede, J.C. [LAMP, Universite de Nantes, 2 Rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France); Addou, M. [LOPCM, Universite d' Ibn Tofail, Kenitra (Maroc)

    2006-06-15

    NiO thin films have been deposited by chemical spray pyrolysis from nickel chloride hexahydrate (NiCl{sub 2}.6H{sub 2}O) solution in water. The substrate temperature during deposition is around 350{sup o}C. The solution flow rate was 10ml/min. The nickel chloride concentration in the solvent has been used as parameter. It varies from 0.05 to 0.5M. It is shown that the NiO film properties depend strongly on the nickel chloride concentration. Below 0.3M, the final thickness of a film deposited using 50ml of solution is around 0.5{mu}m. From 0.3 to 0.5M the thickness is around 3{mu}m. There is a threshold value for the different film properties when the precursor concentration varies between C=0.2 and 0.3M. The oxygen concentration present in the films decreases from 1, in the case of small molar concentration, to 0.86 for 0.3M and more. In the X-ray diffraction diagram, the more intense contribution is systematically the (111) peak, while the (200) diffraction peak is small. This last peak increases slowly up to 0.3M with the NiCl{sub 2} concentration, and then it stabilizes. Also, the conductivity decreases when the molar concentration of NiCl{sub 2} increases, to stabilize at around 0.3M. Moreover, while, as expected, the films are p-type when the molar concentration is smaller than 0.3M, they becomes n-type for higher concentrations. The increase in the deposition rate induces a significant increase in the grow rate of the NiO thin film, which can explain the decrease in grain orientation and oxygen concentration. The threshold value experimentally measured should be related to the reaction kinetics between Ni and O during spray pyrolysis. NiO is shown as a p-type extrinsic semiconductor in which Ni vacancies lead to p-type conductivity. Moreover, the presence of Ni{sup 3+} in the films, as shown by XPS and the brown color of the films, enhances the p-type character of the films. When the O/Ni at% ratio decreases as the precursor concentration increases, the Ni

  20. LiCoO/sub 2/ structures by spray pyrolysis technique for rechargeable Li-ion battery

    International Nuclear Information System (INIS)

    As the lithium-ion batteries have high energy density, Lithium-batteries have become a very attractive field of study for the researchers. Batteries' high energy density is up to the anode and cathode materials used in the batteries and the technique which is chosen for getting these materials. In this study, LiCoO/sub 2/, used for cathode active material in lithium ion batteries, has been prepared with spraying on a glass base by spray pyrolysis technique. LiCoO/sub 2 /was annealed at 600 deg. C for 3h in an air atmosphere; and crystal structures of the obtained samples were examined with XRD, the surface morphology of them was examined with SEM. Effect of annealing on crystallization has been investigated in prepared samples. (author)

  1. Surfactant-assisted ultrasonic spray pyrolysis of nickel oxide and lithium-doped nickel oxide thin films, toward electrochromic applications

    International Nuclear Information System (INIS)

    Highlights: • Surfactant-assisted USP: a novel and low cost process to obtain high quality nickel oxide films, with or without lithium dopant. • Increased uniformity and reduced light scattering thanks to the addition of a surfactant. • Improved electrochromic performance (coloration efficiency and contrast) for lithium-doped films by comparison with the undoped NiO film. - Abstract: Lithium-doped nickel oxide and undoped nickel oxide thin films have been deposited on FTO/glass substrates by a surfactant-assisted ultrasonic spray pyrolysis. The addition of polyethylene glycol in the sprayed solution has led to improved uniformity and reduced light scattering compared to films made without surfactant. Furthermore, the presence of lithium ions in NiO films has resulted in improved electrochromic performances (coloration contrast and efficiency), but with a slight decrease of the electrochromic switching kinetics

  2. Structural, optical and electrical properties of Al-doped ZnO microrods prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Al-doped ZnO thin films were obtained on glass substrates by spray pyrolysis in air atmosphere. The molar ratio of Al in the spray solution was changed in the range of 0-20 at.% in steps of 5 at.%. X-ray diffraction patterns of the films showed that the undoped and Al-doped ZnO films exhibited hexagonal wurtzite crystal structure with a preferred orientation along (002) direction. Surface morphology of the films obtained by scanning electron microscopy revealed that pure ZnO film grew as quasi-aligned hexagonal shaped microrods with diameters varying between 0.7 and 1.3 μm. However, Al doping resulted in pronounced changes in the morphology of the films such as the reduction in the rod diameter and deterioration in the surface quality of the rods. Nevertheless, the morphology of Al-doped samples still remained rod-like with a hexagonal cross-section. Flower-like structures in the films were observed due to rods slanting to each other when spray solution contained 20 at.% Al. Optical studies indicated that films had a low transmittance and the band gap decreased from 3.15 to 3.10 eV with the increasing Al molar ratio in the spray solution from 0 to 20 at.%.

  3. Structural and optical properties of nanostructural V{sub 2}O{sub 5} thin films deposited by spray pyrolysis technique: Effect of the substrate temperature

    Energy Technology Data Exchange (ETDEWEB)

    Irani, R. [Spray Lab, Physics Department, University of Guilan, Rasht (Iran, Islamic Republic of); Rozati, S.M., E-mail: smrozati@gmail.com [Spray Lab, Physics Department, University of Guilan, Rasht (Iran, Islamic Republic of); Beke, S. [Department of Nanophysics, Istituto Italiano di Tecnologia (IIT), via Morego 30, 16163 Genova (Italy)

    2013-05-15

    V{sub 2}O{sub 5} thin films were deposited on glass substrates by spray pyrolysis technique. The variation in the structural and optical properties with a variation in the substrate temperature was investigated by means of X-ray diffraction (XRD) and UV–vis spectrophotometer. XRD was used to reveal the possible orientations of crystallites in the films prepared at different substrate temperatures ranging from 200 °C to 550 °C. The results showed that by increasing the temperature, the films grew along the (001) direction with an orthorhombic structure. The crystallite size was calculated using the Scherrer equation and observed that it increased with elevating the substrate temperature to 450 °C, but decreased when further increasing it. The highest transmittance was achieved when films were deposited at 550 °C. The absorption edge was estimated by using the Tauc plot. In the range 350 °C–550 °C, a shift of the absorption edge from 2.5 eV to 2.8 eV was observed due to the formation of chemical bonds at the V{sub 2}O{sub 5} film–substrate interface at high substrate temperatures (>450 °C). Field emission scanning electron microscopy showed that nanorods were formed when depositing at 500 °C. We conclude that by altering the substrate temperature the size of crystallites can be well controlled. - Highlights: ► Spray pyrolysis technique was used. ► We have synthesized highly oriented nanocrystalline V{sub 2}O{sub 5} films. ► By altering the substrate temperature the size of crystallites can be well controlled. ► The highest transmittance was achieved when films were deposited at 550 °C. ► Scanning electron microscopy showed that nanorods were formed when depositing at 500 °C.

  4. A study on the sensing of NO2 and O2 utilizing ZnO films grown by aerosol spray pyrolysis

    International Nuclear Information System (INIS)

    The present paper addresses the preparation and characterization of ZnO nanostructured thin films obtained using aerosol spray pyrolysis method at different deposition periods. Aiming at understanding the chemical composition, structural and morphological properties of the samples, characterization was performed using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), atomic force microscopy (AFM) and focused ion beam scanning electron microscopy (FIB-SEM), respectively. Defect structures were characterized by photoluminescence (PL), Raman, and electron paramagnetic resonance (EPR) techniques. The purity and crystallinity of the deposited films with increasing growth time were confirmed from XRD studies supported by Raman studies. AFM and SEM revealed morphology transition from uniform small particles to rod-like structures fused together growing perpendicular to the surface with prolonged deposition time. Optical absorption analyses revealed the decrease in the optical band-gap energy from 3.38 to 3.27 eV with prolonged growth time. The dominant emission at 2.80 eV (445 nm) in the PL spectra signifies the presence of Zni in the ZnO nanostructures which is shown to slightly decrease with an increase in growth time. EPR analyses revealed higher ferromagnetic (FM) signal for ZnO films grown for 20 min. Improved sensitivity to both NO2 and O2 was observed for ZnO nanostructured film grown for 20 min owing to higher Zni and VO as compared to its counterpart. Film grown for longer periods showed a decrease on the FM and sensitivity due to reduced Zni and VO defects induced by larger grain sizes. - Graphical abstract: Display Omitted - Highlights: • Nanostructured ZnO thin films were grown using spray pyrolysis at different growth periods. • Growth time variation led to significant changes in the film thickness and surface morphology. • The origin of the surface related defects emission is explained in detail. • Sensing properties of ZnO thin films

  5. Structural and optical properties of nanostructural V2O5 thin films deposited by spray pyrolysis technique: Effect of the substrate temperature

    International Nuclear Information System (INIS)

    V2O5 thin films were deposited on glass substrates by spray pyrolysis technique. The variation in the structural and optical properties with a variation in the substrate temperature was investigated by means of X-ray diffraction (XRD) and UV–vis spectrophotometer. XRD was used to reveal the possible orientations of crystallites in the films prepared at different substrate temperatures ranging from 200 °C to 550 °C. The results showed that by increasing the temperature, the films grew along the (001) direction with an orthorhombic structure. The crystallite size was calculated using the Scherrer equation and observed that it increased with elevating the substrate temperature to 450 °C, but decreased when further increasing it. The highest transmittance was achieved when films were deposited at 550 °C. The absorption edge was estimated by using the Tauc plot. In the range 350 °C–550 °C, a shift of the absorption edge from 2.5 eV to 2.8 eV was observed due to the formation of chemical bonds at the V2O5 film–substrate interface at high substrate temperatures (>450 °C). Field emission scanning electron microscopy showed that nanorods were formed when depositing at 500 °C. We conclude that by altering the substrate temperature the size of crystallites can be well controlled. - Highlights: ► Spray pyrolysis technique was used. ► We have synthesized highly oriented nanocrystalline V2O5 films. ► By altering the substrate temperature the size of crystallites can be well controlled. ► The highest transmittance was achieved when films were deposited at 550 °C. ► Scanning electron microscopy showed that nanorods were formed when depositing at 500 °C

  6. Low Temperature Synthesis of Fluorine-Doped Tin Oxide Transparent Conducting Thin Film by Spray Pyrolysis Deposition.

    Science.gov (United States)

    Ko, Eun-Byul; Choi, Jae-Seok; Jung, Hyunsung; Choi, Sung-Churl; Kim, Chang-Yeoul

    2016-02-01

    Transparent conducting oxide (TCO) is widely used for the application of flat panel display like liquid crystal displays and plasma display panel. It is also applied in the field of touch panel, solar cell electrode, low-emissivity glass, defrost window, and anti-static material. Fluorine-doped tin oxide (FTO) thin films were fabricated by spray pyrolysis of ethanol-added FTO precursor solutions. FTO thin film by spray pyrolysis is very much investigated and normally formed at high temperature, about 500 degrees C. However, these days, flexible electronics draw many attentions in the field of IT industry and the research for flexible transparent conducting thin film is also required. In the industrial field, indium-tin oxide (ITO) film on polymer substrate is widely used for touch panel and displays. In this study, we investigated the possibility of FTO thin film formation at relatively low temperature of 250 degrees C. We found out that the control of volume of input precursor and exhaust gases could make it possible to form FTO thin film with a relatively low electrical resistance, less than 100 Ohm/sq and high optical transmittance about 88%. PMID:27433704

  7. Photocatalytic Activities of Copper Doped Cadmium Sulfide Microspheres Prepared by a Facile Ultrasonic Spray-Pyrolysis Method

    Directory of Open Access Journals (Sweden)

    Jinzhan Su

    2016-06-01

    Full Text Available Ultrasonic spray pyrolysis is a superior method for preparing and synthesizing spherical particles of metal oxide or sulfide semiconductors. Cadmium sulfide (CdS photocatalysts with different sizes and doped-CdS with different dopants and doping levels have been synthesized to study their properties of photocatalytic hydrogen production from water. The CdS photocatalysts were characterized with scanning electron microscopy (SEM, X-ray fluorescence-spectrometry (XRF, UV-Vis absorption spectra and X-ray diffraction (XRD to study their morphological and optical properties. The sizes of the prepared CdS particles were found to be proportional to the concentration of the metal nitrates in the solution. The CdS photocatalyst with smaller size showed a better photocatalytic activity. In addition, Cu doped CdS were also deposited and their photocatalytic activities were also investigated. Decreased bandgaps of CdS synthesized with this method were found and could be due to high density surface defects originated from Cd vacancies. Incorporating the Cu elements increased the bandgap by taking the position of Cd vacancies and reducing the surface defect states. The optimal Cu-doped level was found to be 0.5 mol % toward hydrogen evolution from aqueous media in the presence of sacrificial electron donors (Na2S and Na2SO3 at a pH of 13.2. This study demonstrated that ultrasonic spray pyrolysis is a feasible approach for large-scale photocatalyst synthesis and corresponding doping modification.

  8. One-Step Synthesis of Pt/Graphene Composites from Pt Acid Dissolved Ethanol via Microwave Plasma Spray Pyrolysis.

    Science.gov (United States)

    Jo, Eun Hee; Chang, Hankwon; Kim, Sun Kyung; Choi, Ji-Hyuk; Park, Su-Ryeon; Lee, Chong Min; Jang, Hee Dong

    2016-01-01

    Pt nanoparticles-laden graphene (Pt/GR) composites were synthesized in the gas phase from a mixture of ethanol and Pt precursor by microwave plasma spray pyrolysis. The morphology of Pt/GR composites has the shape of wrinkled sheets of paper, while Pt nanoparticles (Pt NPs) that are less than 2.6 nm in the mean diameter are uniformly well deposited on the surface of GR sheets stacked in only three layers. The Pt/GR composite prepared with 20 wt% of Pt had the highest specific surface area and electrochemical surface area of up to 402 m(2) g(-1) and 77 m(2) g(-1) (Pt), respectively. In addition, the composite showed superior electrocatalytic activity compared with commercial Pt-carbon black. The excellent electrocatalytic activity was attributed to the high specific surface area and electrochemical surface area of the Pt/GR composite directly produced by microwave plasma spray pyrolysis. Thus, it is clearly expected that the Pt/GR composite is a promising material for DMFC catalysts. PMID:27622908

  9. Synthesis of conductive semi-transparent silver films deposited by a Pneumatically-Assisted Ultrasonic Spray Pyrolysis Technique

    International Nuclear Information System (INIS)

    Highlights: • We deposited metallic silver films without post-deposition annealing. • The spray pyrolysis technique is of low cost and scalable for industrial applications. • We obtained deposition rate of 60 nm min−1 at 300 °C. • The average resistivity was 1E−7 Ω m. • Semi-transparent silver films were obtained at 350 °C and deposition time of 45 s. -- Abstract: The synthesis and characterization of nanostructured silver films deposited on corning glass by a deposition technique called Pneumatically-Assisted Ultrasonic Spray Pyrolysis are reported. Silver nitrate and triethanolamine were used as silver precursor and reducer agent, respectively. The substrate temperatures during deposition were in the range of 300–450 °C and the deposition times from 30 to 240 s. The deposited films are polycrystalline with cubic face-centered structure, and crystalline grain size less than 30 nm. Deposition rates up to 600 Å min−1 were obtained at substrate temperature as low as 300 °C. The electrical, optical, and morphological properties of these films are also reported. Semi-transparent conductive silver films were obtained at 350 °C with a deposition time of 45 s

  10. Synthesis of conductive semi-transparent silver films deposited by a Pneumatically-Assisted Ultrasonic Spray Pyrolysis Technique

    Energy Technology Data Exchange (ETDEWEB)

    Zaleta-Alejandre, E.; Balderas-Xicoténcatl, R. [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, , Apdo. Postal 14-470, Del, Gustavo A. Madero, C.P. 07000, México, D.F. (Mexico); Arrieta, M.L. Pérez [Universidad Autónoma de Zacatecas, Unidad Académica de Física, Calzada Solidaridad esq. Paseo, La Bufa s/n, C.P. 98060, Zacatecas, México (Mexico); Meza-Rocha, A.N.; Rivera-Álvarez, Z. [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, , Apdo. Postal 14-470, Del, Gustavo A. Madero, C.P. 07000, México, D.F. (Mexico); Falcony, C., E-mail: cfalcony@fis.cinvestav.mx [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, , Apdo. Postal 14-470, Del, Gustavo A. Madero, C.P. 07000, México, D.F. (Mexico)

    2013-10-01

    Highlights: • We deposited metallic silver films without post-deposition annealing. • The spray pyrolysis technique is of low cost and scalable for industrial applications. • We obtained deposition rate of 60 nm min{sup −1} at 300 °C. • The average resistivity was 1E−7 Ω m. • Semi-transparent silver films were obtained at 350 °C and deposition time of 45 s. -- Abstract: The synthesis and characterization of nanostructured silver films deposited on corning glass by a deposition technique called Pneumatically-Assisted Ultrasonic Spray Pyrolysis are reported. Silver nitrate and triethanolamine were used as silver precursor and reducer agent, respectively. The substrate temperatures during deposition were in the range of 300–450 °C and the deposition times from 30 to 240 s. The deposited films are polycrystalline with cubic face-centered structure, and crystalline grain size less than 30 nm. Deposition rates up to 600 Å min{sup −1} were obtained at substrate temperature as low as 300 °C. The electrical, optical, and morphological properties of these films are also reported. Semi-transparent conductive silver films were obtained at 350 °C with a deposition time of 45 s.

  11. Photocatalytic Activities of Copper Doped Cadmium Sulfide Microspheres Prepared by a Facile Ultrasonic Spray-Pyrolysis Method.

    Science.gov (United States)

    Su, Jinzhan; Zhang, Tao; Li, Yufeng; Chen, Yubin; Liu, Maochang

    2016-01-01

    Ultrasonic spray pyrolysis is a superior method for preparing and synthesizing spherical particles of metal oxide or sulfide semiconductors. Cadmium sulfide (CdS) photocatalysts with different sizes and doped-CdS with different dopants and doping levels have been synthesized to study their properties of photocatalytic hydrogen production from water. The CdS photocatalysts were characterized with scanning electron microscopy (SEM), X-ray fluorescence-spectrometry (XRF), UV-Vis absorption spectra and X-ray diffraction (XRD) to study their morphological and optical properties. The sizes of the prepared CdS particles were found to be proportional to the concentration of the metal nitrates in the solution. The CdS photocatalyst with smaller size showed a better photocatalytic activity. In addition, Cu doped CdS were also deposited and their photocatalytic activities were also investigated. Decreased bandgaps of CdS synthesized with this method were found and could be due to high density surface defects originated from Cd vacancies. Incorporating the Cu elements increased the bandgap by taking the position of Cd vacancies and reducing the surface defect states. The optimal Cu-doped level was found to be 0.5 mol % toward hydrogen evolution from aqueous media in the presence of sacrificial electron donors (Na₂S and Na₂SO₃) at a pH of 13.2. This study demonstrated that ultrasonic spray pyrolysis is a feasible approach for large-scale photocatalyst synthesis and corresponding doping modification. PMID:27314320

  12. Polymetallic citric complexes as precursors for spray-pyrolysis deposition of thin LaFeO3 films

    International Nuclear Information System (INIS)

    A method for the deposition of thin films of the perovskite LaFeO3 on glass is proposed. The films are prepared by spray pyrolysis using an ethylene glycol solution of mixed metal citrate complexes and O2 or N2 as carrier gas at substrate temperatures between 350 °C and 400 °C and post-deposition annealing at 350–480 °C in air. The phase composition, crystal structure, morphology and adhesion of the prepared films (40–600 nm thick) are studied by X-ray diffraction, energy dispersive X-ray microanalysis, scanning electron microscopy, and atomic force microscopy. The influence of the conditions of deposition and post-deposition annealing is studied and optimal parameters of the procedure are described. Single phase dense uniform films with crystallites of approx. 30 nm are obtained. - Highlights: • A method for spray-pyrolysis deposition of thin films of LaFeO3 is proposed. • Mixed metal citrate complexes in ethylene glycol are used as a starting material. • Films with thickness varying from 40 to 600 nm are prepared. • Stoichiometric, uniform and dense films with good adhesion are obtained

  13. The effects of calcination temperature on the electrochemical performance of LiMnPO4 prepared by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Research highlights: → Carbon-coated LiMnPO4 cathode materials were prepared by ultrasonic spray pyrolysis. → The effects of calcinations temperature on the microstructure and electrochemical performance of C-LiMnPO4 were investigated. → X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations revealed that the calcination temperature had a strong influence on the morphology and crystallite size of the prepared final powder, and therefore the subsequent electrochemical performance of the material. → The C-LiMnPO4 powders prepared at 650 oC exhibited excellent electrochemical performance with a discharge capacity of 118 mAh g-1. - Abstract: Carbon-coated LiMnPO4 powders were prepared by ultrasonic spray pyrolysis. The effects of calcination temperature on the microstructure and electrochemical performance of C-LiMnPO4 were investigated. X-ray diffraction (XRD) studies showed that the crystallite size varied with calcination temperature. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations revealed that the calcination temperature had a strong influence on the morphology of the prepared final powder, and therefore the subsequent electrochemical performance of the material. The C-LiMnPO4 powders prepared at 650 oC exhibited excellent electrochemical performance with a discharge capacity of 118 mAh g-1.

  14. All spray pyrolysis deposited CdS sensitized ZnO films for quantum dot-sensitized solar cells

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted Research highlights: → Solar cells based on CdS quantum dot sensitized ZnO photoanode are fabricated. → Both ZnO and CdS are prepared using ultrasonic spray pyrolysis technique. → Good contact is formed between CdS and ZnO to facilitate the electron transfer. → As-prepared cell achieves maximally a power conversion efficiency of 1.54%. - Abstract: Sensitized-type solar cells based on ZnO photoanode and CdS quantum dots (QDs) as sensitizers have been fabricated. Both ZnO films and CdS QDs are prepared using ultrasonic spray pyrolysis (USP) deposition technique. This method allows a facile and rapid deposition and integration between CdS QDs and ZnO films without the need for post thermal treatment. The photovoltaic performances of the cells are investigated. The results show that the performance of the cell based on all USP deposited CdS sensitized ZnO photoanode achieves maximally a short circuit current density of 6.99 mA cm-2 and a power conversion efficiency of 1.54%.

  15. Boron doped nanostructure ZnO films deposited by ultrasonic spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Karakaya, Seniye, E-mail: seniyek@ogu.edu.tr; Ozbas, Omer

    2015-02-15

    Highlights: • Nanostructure undoped and boron doped ZnO films were deposited by USP technique. • Influences of doping on the surface and optical properties of the ZnO films were investigated. • XRD spectra of the films exhibited a variation in crystalline quality depending on the B content. - Abstract: ZnO is an II–VI compound semiconductor with a wide direct band gap of 3.3 eV at room temperature. Doped with group III elements (B, Al or Ga), it becomes an attractive candidate to replace tin oxide (SnO{sub 2}) or indium tin oxide (ITO) as transparent conducting electrodes in solar cell devices and flat panel display due to competitive electrical and optical properties. In this work, ZnO and boron doped ZnO (ZnO:B) films have been deposited onto glass substrates at 350 ± 5 °C by a cost-efficient ultrasonic spray pyrolysis technique. The optical, structural, morphological and electrical properties of nanostructure undoped and ZnO:B films have been investigated. Electrical resistivity of films has been analyzed by four-probe technique. Optical properties and thicknesses of the films have been examined in the wavelength range 1200–1600 nm by using spectroscopic ellipsometry (SE) measurements. The optical constants (refractive index (n) and extinction coefficient (k)) and the thicknesses of the films have been fitted according to Cauchy model. The optical method has been used to determine the band gap value of the films. Transmission spectra have been taken by UV spectrophotometer. It is found that both ZnO and ZnO:B films have high average optical transmission (≥80%). X-ray diffraction (XRD) patterns indicate that the obtained ZnO has a hexagonal wurtzite type structure. The morphological properties of the films were studied by atomic force microscopy (AFM). The surface morphology of the nanostructure films is found to depend on the concentration of B. As a result, ZnO:B films are promising contender for their potential use as transparent window layer and

  16. Boron doped nanostructure ZnO films deposited by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Highlights: • Nanostructure undoped and boron doped ZnO films were deposited by USP technique. • Influences of doping on the surface and optical properties of the ZnO films were investigated. • XRD spectra of the films exhibited a variation in crystalline quality depending on the B content. - Abstract: ZnO is an II–VI compound semiconductor with a wide direct band gap of 3.3 eV at room temperature. Doped with group III elements (B, Al or Ga), it becomes an attractive candidate to replace tin oxide (SnO2) or indium tin oxide (ITO) as transparent conducting electrodes in solar cell devices and flat panel display due to competitive electrical and optical properties. In this work, ZnO and boron doped ZnO (ZnO:B) films have been deposited onto glass substrates at 350 ± 5 °C by a cost-efficient ultrasonic spray pyrolysis technique. The optical, structural, morphological and electrical properties of nanostructure undoped and ZnO:B films have been investigated. Electrical resistivity of films has been analyzed by four-probe technique. Optical properties and thicknesses of the films have been examined in the wavelength range 1200–1600 nm by using spectroscopic ellipsometry (SE) measurements. The optical constants (refractive index (n) and extinction coefficient (k)) and the thicknesses of the films have been fitted according to Cauchy model. The optical method has been used to determine the band gap value of the films. Transmission spectra have been taken by UV spectrophotometer. It is found that both ZnO and ZnO:B films have high average optical transmission (≥80%). X-ray diffraction (XRD) patterns indicate that the obtained ZnO has a hexagonal wurtzite type structure. The morphological properties of the films were studied by atomic force microscopy (AFM). The surface morphology of the nanostructure films is found to depend on the concentration of B. As a result, ZnO:B films are promising contender for their potential use as transparent window layer and

  17. Obtention of zirconia films stabilized with Yttria via pyrolysis spray: study of the solvent influence; Obtencao de filmes de zirconia estabilizada com itria via spray pirolise: estudo da influencia do solvente

    Energy Technology Data Exchange (ETDEWEB)

    Halmenschlager, Cibele Melo; Vieira, Ramaugusto da Porciuncula; Takimi, Antonio Shigueaki; Bergmann, Carlos Perez; Silva, Aline Lima da; Malfatti, Celia de Fraga [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia de Minas, Metalurgica e de Materiais (PPGEM). Lab. de Materiais Ceramicos (LACER)]. E-mail: cibelemh@yahoo.com.br

    2008-07-01

    Yttria-stabilized-zirconia (YSZ) has been object of many studies, due to its great chemical stability and excellent ionic conduction in high temperature. This material has been studies with an intention of to be used with electrolyte of oxide solid fuel cells, which work in high temperature. The aim of the present work was to evaluate the influence of the solvent on the elaboration of crystalline films of YSZ via spray pyrolysis. The film was prepared by spray pyrolysis with zirconium acetylacetonate (Zr(C{sub 6}H{sub 7}O{sub 2}){sub 4}) and yttrium chloride (YCl{sub 3}.6H{sub 2}O), dissolved in different solvents: ethanol (C{sub 2}H{sub 6}O), ethanol (C{sub 2}H{sub 6}O) + propyleneglycol (C{sub 3}H{sub 8}O{sub 2}) with volume ratio (1:1) and ethanol (C{sub 2}H{sub 6}O) + diethylene glycol butyl ether (C{sub 8}H{sub 18}O{sub 3}) with volume ratio of 1:1. A disk of steel 316L was used as substrate. The amorphous film was deposited in the substrate heated at 280 deg C {+-} 50 deg C. After deposition from thermal treatment at 700 deg C the amorphous film was changed into Yttria-stabilized-zirconia film. The thermal behavior of the films has been studied by both (DTA/TGA) thermogravimetric and mass spectroscopy analyses. The morphology and crystalline phase of the films was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The YSZ film obtained after heat treatment was dense and crystalline, however, the analyses indicate a significant influence of the solvent and of the substrate temperature during the deposition process on the film morphology.(author)

  18. Superior Na-ion storage properties of high aspect ratio SnSe nanoplates prepared by a spray pyrolysis process

    Science.gov (United States)

    Park, Gi Dae; Lee, Jong-Heun; Kang, Yun Chan

    2016-06-01

    SnSe nanoplates with thin and uniform morphology are prepared by one-pot spray pyrolysis, and are examined as anode materials for Na-ion batteries. During the spray pyrolysis process, metallic Se and Sn are prepared from SeO2 and SnO2, respectively, under a reducing atmosphere. Metallic Sn and metalloid Se, with melting points of 232 and 221 °C, respectively, form a melted Sn-Se mixture, which reacts exothermally to form SnSe nanocrystals. Several of these nanocrystals are grown simultaneously forming a micron-sized powder. Complete elimination of the excess amount of metalloid Se, by forming H2Se gas, results in aggregation-free SnSe nanoplates. The aspect ratio of these nanoplates is as high as 11.3. The discharge capacities for the SnSe nanoplates, prepared from spray solutions containing 100, 400, and 800% of the stoichiometric SeO2 content needed to form SnSe, are 407, 558, and 211 mA h g-1, respectively, after 50 cycles at a constant current density of 0.3 A g-1 their capacity retentions calculated from the second cycle onwards are 77, 100, and 60%, respectively. The phase pure SnSe nanoplates with a high aspect ratio show good cycling and rate performances for Na-ion storage.SnSe nanoplates with thin and uniform morphology are prepared by one-pot spray pyrolysis, and are examined as anode materials for Na-ion batteries. During the spray pyrolysis process, metallic Se and Sn are prepared from SeO2 and SnO2, respectively, under a reducing atmosphere. Metallic Sn and metalloid Se, with melting points of 232 and 221 °C, respectively, form a melted Sn-Se mixture, which reacts exothermally to form SnSe nanocrystals. Several of these nanocrystals are grown simultaneously forming a micron-sized powder. Complete elimination of the excess amount of metalloid Se, by forming H2Se gas, results in aggregation-free SnSe nanoplates. The aspect ratio of these nanoplates is as high as 11.3. The discharge capacities for the SnSe nanoplates, prepared from spray solutions

  19. Growth of γ-In2Se3 thin films by electrostatic spray pyrolysis deposition

    International Nuclear Information System (INIS)

    Full text : The electrostatic spray pyrolysis deposition (ESPD) growth technique has the advantages that the crystal growth is carried out in a non-vacuum atmosphere, the sizes of the droplets are very small below an order of micrometer and the growth rate is slow compared with the conventional spray pyrolysis deposition (SPD) technique. Therefore, it is expected to grow good crystalline thin films at a low cost. The γ-In2Se3 is an attractive material for a top cell of tandem-type solar cells because of its energy gap value of 1.9 eV. However, the In2Se3 system has usually been grown under a vacuum such as an MBE or a vacuum evaporation technique. There are few reports about the SPD growth or ESPD growth of In2Se3. In this abstract, it is reported the growth and the characterization of γ-In2Se3 films by the ESPD growth technique. InCl3 and N,N-Dimethyl selenourea were used as source materials and they were dissolved in ethanol. The typical concentration of InCl3 was 6*10-3 mol/l and the Se/In atomic ratio ranged from 1.2 to 5. The film thickness was about 1 μm after a 3 h growth period under an applied voltage of 25kV between the source solution and the glass substrates. The XRD spectra of films grown at a constant Se/In ratio of 2.0 and various substrate temperatures (Ts). The γ-In2Se3 peaks were observed at the substrate temperature (Ts) range from 235 to 280 degrees Celsium. The growth of γ-In2Se3 was also confirmed by the Raman spectrum peak located at 151cm-1, which was known as a γ-In2Se3 mode peak. The InSe was grown below 215 degrees Celsium. The γ-In2Se3 diffraction peak becomes dominant around Ts =250 degrees Celsium. The full width at half maximum of this peak had a minimum value at around Ts=250 degrees Celsium. The diffraction intensity ratio of (11-20) /(0006) also had a minimum value of about 0.02 at this Ts. This shows that the grown films are strongly oriented to [0001] direction. The film thickness decreases with decreasing In concentration

  20. Influence of aluminum doping in CuInS2 prepared by spray pyrolysis on different substrates

    International Nuclear Information System (INIS)

    The structural and optical properties of the CuInS2 semiconductor thin films doped with aluminum ([Al]/[In] = 1 per mille and 2 per mille ) are reported. Films are deposited using the spray pyrolysis technique on various substrates: glass, In2S3/glass, ZnO/glass, as well as SnO2/glass, In2S3 and ZnO are used as optical windows in photovoltaic system, CuInS2 as the absorber material and SnO2 as ohmic contact. In2S3, ZnO and SnO2 are grown by spray pyrolysis. During CuInS2 thin layer deposition, the substrate temperature is 340 oC. The deposition run lasts for 5 min. X-ray diffraction is used to characterize CuInS2 film cristallinity. The effect of aluminum inclusions as well as of the substrate material on the CuInS2 film is investigated. The optical absorption coefficient α for the Al-doped CuInS2 compounds is obtained from reflection and transmission spectra. It is in the range of [3.69-4.37] x 106 cm-1 ([9.55-12.31] x 106 cm-1, respectively) for 1 per mille aluminum content in the spray solution (2 per mille , respectively). The direct band gap value is in the order of 1.44 eV for the 1 per mille Al-doped CuInS2 thin layers and 1.48 eV for 2 per mille Al content.

  1. Production of brown algae pyrolysis oils for liquid biofuels depending on the chemical pretreatment methods

    International Nuclear Information System (INIS)

    Highlights: • Pyrolysis of Saccharina japonica, brown algae to produce hydrocarbons. • Sulfuric acid pretreatment of macroalgae to remove inorganic elements. • CaCl2 treatment of macroalgae to remove valuable fucoidan. • Sulfuric acid pretreatment suppressed the formation of large biochar chunks. • The pretreatment methods allowed the continuous operation of pyrolysis. - Abstract: Based on observations of rapidly growing biochar in fluidization beds, kelp (Saccharina japonica), a species of brown algae, was pretreated for the efficient operation of pyrolysis processes to produce pyrolysis oils. The removal of catalytically active inorganic minerals and the softening of polymeric seaweed structures were performed by means of chemical treatments, including a CaCl2 treatment to isolate valuable and sticky fucoidan and a sulfuric acid treatment to remove catalytically active minerals. The sulfuric acid pretreatment significantly reduced the inorganic elements but did not significantly affect the properties of the pyrolysis oil compared to the non-treated kelp pyrolysis oil. Whereas the non-treated kelp produced significantly large chunks of biochar, which hindered the continuous operation of pyrolysis, the kelp treated with sulfuric acid did not produce aggregated large particles of biochar, thereby offering a means of developing reliable continuous pyrolysis processes

  2. Modifying Optical Properties of ZnO Films by Forming Zn[subscript 1-x] Co[subscript x]O Solid Solutions via Spray Pyrolysis

    Science.gov (United States)

    Bentley, Anne K.; Weaver, Gabriela C.; Russell, Cianan B.; Fornes, William L.; Choi, Kyoung-Shin; Shih, Susan M.

    2007-01-01

    A simple and cost-effective experiment for the development and characterization of semiconductors using Uv-vis spectroscopy is described. The study shows that the optical properties of ZnO films can be easily modified by forming Zn[subscript 1-x] Co[subscript x]O solid solutions via spray pyrolysis.

  3. Microstructural and electrical characterizations of tungsten-doped La2Mo2O9 prepared by spray pyrolysis

    DEFF Research Database (Denmark)

    Baqué, Laura; Vega-Castillo, Jesús; Georges, Samuel;

    2013-01-01

    La2Mo2 − xWxO9 (x=0, 0.5, 1.0, and 1.3) nanocrystalline powders were synthesized by spray pyrolysis (SP) assisted by an ultrasonic atomizer. Microstructure, sinterability and thermal stability of the prepared powders were investigated. Spherical particles of 430 to 530 nm in diameter and crystall...

  4. Effect of annealing on the properties of nanocrystalline CuInSSe thin films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Shrotriya, Vipin, E-mail: vipinshrotriya@gmail.com; Rajaram, P. [School of Studies in Physics, Jiwaji University, Gwalior (MP), India-474011 (India)

    2015-08-28

    The effect of annealing CuInSSe thin films, which were grown on glass substrates using the spray pyrolysis technique from spray solutions having S/Se ionic ratio 0.6, were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and optical transmission measurements. The CuInSSe films were co-deposited from an aqueous solution containing CuCl{sub 2}, InCl{sub 3}, thiourea and SeO{sub 2}. EDC was used as a complexing agent and films were deposited at the constant temperature 300°C. Post annealing (at 350°C) was used to improve the structural, morphological and optical properties of CuInSSe thin films. From the results, it is found that the films are single phase, p-type in conductivity having the chalcopyrite structure. From the Scherrer formula the average size of the films was found to be in the range (15-28) nm. Optical studies show that the optical band gap value increases slightly from 1.35 eV to 1.37 eV with annealing for films grown from spray solutions having S/Se ionic ratio 0.6.

  5. Two-Nozzle Flame Spray Pyrolysis (FSP) Synthesis of CoMo/Al2O3 Hydrotreating Catalysts

    DEFF Research Database (Denmark)

    Høj, Martin; Pham, David K.; Brorson, Michael;

    2013-01-01

    Two-nozzle frame spray analysis (FSP) synthesis of CoMo/Al2O3 where Co and Al are sprayed in separate flames was applied to minimize the formation of CoAl2O4 observed in one-nozzle flame spray pyrolysis (FSP) synthesis and the materials were characterized by N2-adsorption (BET), X-ray diffraction...... at short flame mixing distances, where the flame conditions resemble one-nozzle FSP. Raman spectroscopy revealed that β-CoMoO4 was a component of all the catalysts (in the as-prepared oxidic form) together with alumina supported MoO x surface species. The only phase detected with XRD was γ-Al2O3. The FSP...... synthesized oxidic catalysts were activated by sulfidation without further heat treatments. The hydrodesulfurization activity of the best two-nozzle FSP catalysts, compared to the one-nozzle FSP catalysts, improved from 75 to 91 % activity relative to a commercial reference catalyst...

  6. Synthesis of BICUVOX solid electrolyte thin film on tantalum substrate by spray pyrolysis technique for biomedical sensors

    International Nuclear Information System (INIS)

    Solid electrolytes find their application in many fields of technological interest such as oxygen sensor, fuel cell, and oxygen pump. Oxygen sensors form a basic component of biomedical instrumentation. Out of all known oxygen ion conducting solid electrolytes, metal ion substituted bismuth vanadate exhibits maximum oxygen ion conductivity at comparatively lower temperature. Thin film of Bi2Cu0.1 V0.9O5.35 was synthesized by an innovative and cost effective spray pyrolysis technique at 493 K on tantalum substrate. Tantalum is a metal with high oxygen affinity. The precursor solution was sprayed on pre heated tantalum substrate, at an optimized spray rate to obtain a uniform film. Film was then annealed at 973 K for two hours to obtain required ion conducting phase. The phase was confirmed with XRD studies. The bulk ionic conductivity of the film was measured by the method of electrochemical impedance spectrometry. The impedance measurements were done in the frequency range 1Hz to 10MHz with respect to temperature. The measurements were carried out in air ambience i.e. at 0.21 oxygen partial pressure. The ionic conductivity was found to be increasing with increase in temperature. It is about 2.53x10-5 (ohm cm)-l at 864K. The lessening of conductivity is attributed in this case to phase separation in the film. Oxygen ion conducting film on metallic substrate is expected to serve as good oxygen sensor in biomedical instrumentation. (author)

  7. Effect of annealing on the properties of nanocrystalline CuInSSe thin films deposited by spray pyrolysis

    International Nuclear Information System (INIS)

    The effect of annealing CuInSSe thin films, which were grown on glass substrates using the spray pyrolysis technique from spray solutions having S/Se ionic ratio 0.6, were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and optical transmission measurements. The CuInSSe films were co-deposited from an aqueous solution containing CuCl2, InCl3, thiourea and SeO2. EDC was used as a complexing agent and films were deposited at the constant temperature 300°C. Post annealing (at 350°C) was used to improve the structural, morphological and optical properties of CuInSSe thin films. From the results, it is found that the films are single phase, p-type in conductivity having the chalcopyrite structure. From the Scherrer formula the average size of the films was found to be in the range (15-28) nm. Optical studies show that the optical band gap value increases slightly from 1.35 eV to 1.37 eV with annealing for films grown from spray solutions having S/Se ionic ratio 0.6

  8. Effect of Solution Molarity, Substrate Temperature and Spray Time on The Structural and Optical Properties Of ZnO Thin Films Deposited By Spray Pyrolysis

    International Nuclear Information System (INIS)

    Zinc oxide thin films were deposited on a glass substrate by spray pyrolysis technique using solution of zinc acetate and air as the carrier gas. Effects of solution molarity, substrate temperature and spray time on films properties were investigated. All films deposited were characterized using X-ray diffraction for structural characterization and UV-VIS transmission spectrophotometry for optical properties. According to the analytical method, the type of crystal lattice was found to be hexagonal and X-ray diffraction (XRD) patterns showed that the films deposited were polycrystalline with (002) plane as preferential orientation. The values of lattice constant, grain size, micro strain and dislocation density of all samples were calculated. In addition, Optical behaviors of film samples were analyzed by obtaining transmission spectra, in the wavelength range of 350-800 nm. The UV-VIS spectroscopy shows the high transparency of ZnO films in the UV region. An optimization of the films has been carried out to determine the best preparation conditions.

  9. Investigations of superparamagnetism in magnesium ferrite nano-sphere synthesized by ultrasonic spray pyrolysis technique for hyperthermia application

    International Nuclear Information System (INIS)

    In this paper, we present the synthesized of magnesium ferrite (MgFe2O4) nano-spheres by a single-step ultrasonic spray pyrolysis (USP) technique from the aqueous metal nitrate precursor solution without any organic additives or post-annealing processes. The effects of different pyrolysis temperatures on the particles size, morphology and their superparamagnetic behavior have been investigated to evaluate the heat generation efficiency in an AC magnetic field. The X-ray powder diffraction spectra of MgFe2O4 nano-spheres synthesized at the pyrolysis temperatures of 600, 700, 800 and 900 °C exhibited single phase cubic structure and obtained mean crystallite size (primary particles) of 4.05, 9.6, 15.97 and 31.48 nm, respectively. Transmission electron microscopy (TEM) confirms that the particles consisted of aggregates of the primary crystallite had densely congested spherical morphology with extremely smooth surface appearance. Field emission electron microscopy (FESEM) reveals that the shape and size of the nano-spheres (secondary particles) does not change significantly but the degree of agglomeration between the secondary particles was reduced with increasing the pyrolysis temperature. The average size and size distribution of nano-spheres measured using electrophoretic scattering photometer have found very low polydispersity index (PDI) for all samples. The field dependent magnetization studies indicated superparamagnetic nature for the particles having crystallite size i.e. 4.05 and 9.6 nm and exhibited ferromagnetic nature for 15.97 and 31.48 nm. It is also demonstrated that, as the pyrolysis temperature increases, the saturation magnetization of the MgFe2O4 nanopowders increases due to enhancement of crystallites. The shift in Curie temperature is well described by the finite-size scaling formula. The magnetically loss heating values of selected samples in crystallite size of 9.6 and 15.97 nm were investigated by measuring the time dependent temperature

  10. Investigations of superparamagnetism in magnesium ferrite nano-sphere synthesized by ultrasonic spray pyrolysis technique for hyperthermia application

    Science.gov (United States)

    Das, Harinarayan; Sakamoto, Naonori; Aono, Hiromichi; Shinozaki, Kazuo; Suzuki, Hisao; Wakiya, Naoki

    2015-10-01

    In this paper, we present the synthesized of magnesium ferrite (MgFe2O4) nano-spheres by a single-step ultrasonic spray pyrolysis (USP) technique from the aqueous metal nitrate precursor solution without any organic additives or post-annealing processes. The effects of different pyrolysis temperatures on the particles size, morphology and their superparamagnetic behavior have been investigated to evaluate the heat generation efficiency in an AC magnetic field. The X-ray powder diffraction spectra of MgFe2O4 nano-spheres synthesized at the pyrolysis temperatures of 600, 700, 800 and 900 °C exhibited single phase cubic structure and obtained mean crystallite size (primary particles) of 4.05, 9.6, 15.97 and 31.48 nm, respectively. Transmission electron microscopy (TEM) confirms that the particles consisted of aggregates of the primary crystallite had densely congested spherical morphology with extremely smooth surface appearance. Field emission electron microscopy (FESEM) reveals that the shape and size of the nano-spheres (secondary particles) does not change significantly but the degree of agglomeration between the secondary particles was reduced with increasing the pyrolysis temperature. The average size and size distribution of nano-spheres measured using electrophoretic scattering photometer have found very low polydispersity index (PDI) for all samples. The field dependent magnetization studies indicated superparamagnetic nature for the particles having crystallite size i.e. 4.05 and 9.6 nm and exhibited ferromagnetic nature for 15.97 and 31.48 nm. It is also demonstrated that, as the pyrolysis temperature increases, the saturation magnetization of the MgFe2O4 nanopowders increases due to enhancement of crystallites. The shift in Curie temperature is well described by the finite-size scaling formula. The magnetically loss heating values of selected samples in crystallite size of 9.6 and 15.97 nm were investigated by measuring the time dependent temperature

  11. Spin wave study and optical properties in Fe-doped ZnO thin films prepared by spray pyrolysis technique

    Science.gov (United States)

    Lmai, F.; Moubah, R.; El Amiri, A.; Abid, Y.; Soumahoro, I.; Hassanain, N.; Colis, S.; Schmerber, G.; Dinia, A.; Lassri, H.

    2016-07-01

    We investigate the magnetic and optical properties of Zn1-xFexO (x = 0, 0.03, 0.05, and 0.07) thin films grown by spray pyrolysis technique. The magnetization as a function of temperature [M (T)] shows a prevailing paramagnetic contribution at low temperature. By using spin wave theory, we separate the M (T) curve in two contributions: one showing intrinsic ferromagnetism and one showing a purely paramagnetic behavior. Furthermore, it is shown that the spin wave theory is consistent with ab-initio calculations only when oxygen vacancies are considered, highlighting the key role played by structural defects in the mechanism driving the observed ferromagnetism. Using UV-visible measurements, the transmittance, reflectance, band gap energy, band tail, dielectric coefficient, refractive index, and optical conductivity were extracted and related to the variation of the Fe content.

  12. Effect of sample producing conditions on the thermoluminescence properties of ZnS thin films developed by spray pyrolysis method

    CERN Document Server

    Yazici, A N; Bedir, M

    2003-01-01

    In this work, the effect of thin film production conditions (substrate temperature and ratio of starting material) was studied on the intensity of thermoluminescence (TL) signal and TL emission spectrum of ZnS samples that were grown by spray pyrolysis method. It was observed that the intensity of TL signal increases with increasing the substrate temperature (T sub s) and reaches a maximum point at the substrate temperature of 500 deg. C with a high ratio of ZnCl sub 2 salt solutions. Secondly, it was observed that the energy level of trap present in ZnS samples is not single-level but instead has a distribution of energy levels. The type of the trap distribution is probably an exponential distribution. However, the distribution of energy levels approaches to single energy level with increasing substrate temperature.

  13. Optical, electrical and surface properties of annealed CdO:Mg thin films prepared by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Karakaya, Seniye, E-mail: seniyek@ogu.edu.tr, E-mail: oozbas@ogu.edu.tr; Ozbas, Omer, E-mail: seniyek@ogu.edu.tr, E-mail: oozbas@ogu.edu.tr [Eskisehir Osmangazi University, Physics Department, Eskisehir (Turkey)

    2013-12-16

    The use of transparent conducting oxides in optoelectronic and photovoltaic devices has encouraged research on this field in recent years. Especially, cadmium oxide is a promising material for solar cell application but also for photodiodes and gas sensors. Mg doped CdO (CdO:Mg) films have been prepared on glass substrates by the ultrasonic spray pyrolysis (USP) technique. After the production, the films have been annealed in air atmosphere at 475°C and half hour. Results on surface, optical and electrical properties of the films as a function of the thermal annealing have been reported. Thicknesses of the films have been determined by the filmetrics thin film measurement system. Transmission and absorbance spectra have been taken by UV-vis spectrophotometer. Atomic Force Microscopy (AFM) analysis indicates that the roughness of the surface decreases upon increasing Mg concentration. The minimum resistivity value of the films was 2×10{sup −3} Ω cm.

  14. Magnetic/luminescent core/shell particles synthesized by spray pyrolysis and their application in immunoassays with internal standard

    International Nuclear Information System (INIS)

    Many types of fluorescent nanoparticles have been investigated as alternatives to conventional organic dyes in biochemistry; magnetic beads also have a long history of biological applications. In this work we apply flame spray pyrolysis in order to engineer a novel type of nanoparticle that has both luminescent and magnetic properties. The particles have magnetic cores of iron oxide doped with cobalt and neodymium and luminescent shells of europium-doped gadolinium oxide (Eu:Gd2O3). Measurements by vibrating sample magnetometry showed an overall paramagnetic response of these composite particles. Luminescence spectroscopy showed spectra typical of the Eu ion in a Gd2O3 host-a narrow emission peak centred near 615 nm. Our synthesis method offers a low-cost, high-rate synthesis route that enables a wide range of biological applications of magnetic/luminescent core/shell particles. Using these particles we demonstrate a novel immunoassay format with internal luminescent calibration for more precise measurements

  15. Optical and electrical properties of spray pyrolysis deposited nano-crystalline BiFeO3 films

    Directory of Open Access Journals (Sweden)

    Annapu Reddy Venkateswarlu

    2011-12-01

    Full Text Available The nano-crystalline BiFeO3 were prepared under controlled substrate temperature by spray pyrolysis method. Their structural, optical and electrical properties were studied and correlated. A blueshift (Δλ ∼ 8.17 nm in the absorbance peaks was observed in the films with decrease in grain size. The absorption coefficient spectra show defect transitions at 1.9 and 2.3 eV in large grain size films due to oxygen vacancies. The lowest leakage was observed in smaller grain size (< 20 nm films due to negligible oxygen vacancies, smooth surface roughness and large energy bang gap. The Poole-Frankel conduction mechanism has been found to be the predominant mechanism for the leakage current.

  16. Study of optical and structural properties of CZTS thin films grown by co-evaporation and spray pyrolysis

    Science.gov (United States)

    Moreno, R.; Ramirez, E. A.; Gordillo Guzmán, G.

    2016-02-01

    Results regarding optical and structural properties of Cu2ZnSnS4 (CZTS) thin films prepared by co-evaporation using a novel procedure are compared with those obtained with CZTS films grown using a solution based route. The lattice strain ε and crystallite size D of CZTS films prepared by co-evaporation and by spray pyrolysis were estimated through X-ray diffraction (XRD) measurements using Williamson-Hall-isotropic strain model. The results of estimated average crystallite size of CZTS films by Scherrer and Williamson-Hall plot methods were compared with AFM (atomic force microscopy) measurements. It was found that the average crystallite size measured by Williamson-Hall plot methods agree quite well with AFM results. Further, information regarding the influence of preparation method on both, crystalline phases and the formation of structural defects was achieved through Raman and Urbach energy measurements.

  17. Optimization of growth temperature of multi-walled carbon nanotubes synthesized by spray pyrolysis method and application for arsenic removal

    Directory of Open Access Journals (Sweden)

    S. Mageswari

    2014-12-01

    Full Text Available Multi-walled carbon nanotubes have been synthesized at different temperatures ranging from 550 °C to 750 °C on silica supported Fe-Co catalyst by spray pyrolysis method using Citrus limonum oil under nitrogen atmosphere. The as-grown MWNTs were characterized by scanning electron microscope (SEM, high resolution transmission electron microscope (HRTEM, X-ray diffraction analysis (XRD and Raman spectral studies. The HRTEM and Raman spectroscopic studies confirmed the evolution of MWNTs with the outer diameter between 25 and 38 nm. The possibility of use of as-grown MWNTs as an adsorbent for removal of As (V ions from drinking water was studied. Adsorption isotherm data were interpreted by the Langmuir and Freundlich equations. Kinetic data were studied using Elovich, pseudo-first order and pseudo-second order equations in order to elucidate the reaction mechanism.

  18. Effect of annealing on the properties of zinc oxide nanofiber thin films grown by spray pyrolysis technique

    Science.gov (United States)

    Sadananda Kumar, N.; Bangera, Kasturi V.; Shivakumar, G. K.

    2013-01-01

    Zinc oxide nanofiber thin films have been deposited on glass substrate by spray pyrolysis technique. The X-ray diffraction studies revealed that the films are polycrystalline with the hexagonal structure and a preferred orientation along (002) direction for films annealed for 1 h at 450 °C. Further increase in annealing time changes the preferred orientation to (100) direction. The scanning electron microscopic analysis showed the formation of ZnO nanofiber with an average diameter of approximately 800 nm for annealed films. The compositional analysis of nanofiber ZnO thin films were studied by time of flight secondary ion mass spectroscopy, which indicated oxygen deficiency in the films. The optical properties of annealed films have shown a variation in the band gap between 3.29 and 3.20 eV. The electrical conductivity of the as grown and annealed films showed an increase in the conductivity by two orders of magnitude with increase in annealing duration.

  19. ZnMgO-based UV photodiodes: a comparison of films grown by spray pyrolysis and MBE

    Science.gov (United States)

    Hierro, A.; Tabares, G.; Lopez-Ponce, M.; Ulloa, J. M.; Kurtz, A.; Muñoz, E.; Marín-Borrás, V.; Muñoz-Sanjose, V.; Chauveau, J. M.

    2016-02-01

    Detecting the UV part of the spectrum is fundamental for a wide range of applications where ZnMgO has the potential to play a central role. The shortest achievable wavelength is a function of the Mg content in the films, which in turn is dependent on the growth technique. Moreover, increasing Mg contents lead to an electrical compensation of the films, which directly affects the responsivity of the photodetectors. In addition, the metal-semiconductor interface and the presence of grain boundaries have a direct impact on the responsivity through different gain mechanisms. In this work, we review the development of ZnMgO UV Schottky photodiodes using molecular beam epitaxy and spray pyrolysis, and we analyze and compare the physical mechanisms underlying the photodetector behavior.

  20. S-Rich CdS1−yTey Thin Films Produced by the Spray Pyrolysis Technique

    Directory of Open Access Journals (Sweden)

    Shadia J. Ikhmayies

    2016-03-01

    Full Text Available Understanding the properties of CdSTe ternary alloys is important because they always form at the interface between the CdS window layer and CdTe absorber layer in CdS/CdTe solar cells due to the intermixing. This interdiffusion is necessary because it improves the device performance. Experimental work has been devoted to studying Te rich p-type CdSxTe1−x alloys, but there is a lack of studies on S-rich n-type CdS1−yTey solid solutions. In this work, a review of the structure, morphology, and optical properties of the S-rich n-type CdS1−yTey thin films produced by the spray pyrolysis technique on glass substrates is presented.

  1. In Situ Synthesis and Deposition of Gold Nanoparticles with Different Morphologies on Glass and ITO Substrate by Ultrasonic Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    María de la Garza

    2013-01-01

    Full Text Available Gold nanoparticles were synthesized and deposited in situ by ultrasonic spray pyrolysis on glass and indium tin oxide (ITO substrates. This technique led to the formation of gold nanoparticles with different morphologies without the use of any capping agent. The gold nanoparticles deposited on glass substrate were obtained as nanospheres with an average particle size of 30 nm with some agglomerates; however, the nanoparticles deposited on ITO substrate were obtained with different morphologies, such as triangular nanoprisms, nanorods, nanocubes, and nanorhombus, with particle sizes between 40 and 100 nm. The ITO substrate influenced the morphology of the gold nanoparticles obtained due to changes in the deposition temperature, which also change the crystalline structure of the ITO film on the substrate.

  2. Surface modification of submicronic TiO2 particles prepared by ultrasonic spray pyrolysis for visible light absorption

    International Nuclear Information System (INIS)

    Spherical, submicronic TiO2 assemblage with high specific surface area and controllable phase composition was prepared in the process of ultrasonic spray drying/pyrolysis in a wide temperature range (150–800 °C) by using as a precursor aqueous colloidal solution consisting of TiO2 nanoparticles (4.5 nm). Submicronic, soft and grained spherical TiO2 particles (d = 370–500 nm) comprising clustered nanocrystals (2 particles through the formation of charge-transfer (CT) complex was achieved with different ligands: ascorbic acid, dopamine, catechol, 2,3-dihydroxynaphthalene, and anthrarobin. Optical properties of the surface-modified TiO2 particles were studied by using diffuse reflection spectroscopy. The binding structure between the surface titanium atoms and different ligands was determined by using Fourier transform infrared spectroscopy. The formation of CT complexes induced significant red shift of optical absorption in comparison to unmodified TiO2 particles.

  3. Low-temperature spray-pyrolysis of FeS2 films and their electrical and optical properties

    Science.gov (United States)

    Orletskii, I. G.; Mar'yanchuk, P. D.; Maistruk, E. V.; Solovan, M. N.; Brus, V. V.

    2016-01-01

    Iron disulfide (FeS2) films with a wide range of electrical resistivities 100 Ω cm ⩽ ρ ⩽ 800 kΩ cm, a high adhesion to the substrate, and a resistance to aggressive media have been prepared by the spray pyrolysis of aqueous solutions of the salts FeCl3 · 6H2O and (NH2)2CS at low temperatures in the range 250°C ⩽ T S ⩽ 400°C. It has been found that the FeS2 films have a high transmittance T ≈ 60-70% and are characterized by a sharp transmission edge. It has been shown that the optical band gap for direct ( E g op = 2.19-2.78 eV) and indirect ( E g 'op = 1.26-1.36 eV) optical transitions depends on the conditions of film preparation.

  4. Influence of Growth Temperature on Structure and Optical Properties of Tin Oxide Films by Spray Pyrolysis Method

    Directory of Open Access Journals (Sweden)

    Y. Larbah

    2015-10-01

    Full Text Available Tin oxide films (SnO2 are prepared by the spray pyrolysis technique at different temperatures. The XRD measurement confirm that the thin films grown by this technique have good crystalline tetragonal rutile structures. The observations by scanning electron microscopy indicate that polycrystalline SnO2 film surfaces were formed by pyramidal grains (200 nm 300 nm, The composition on the films was obtained by Auger electron spectroscopy (AES, which is identical to the analysis EDS. Characterization by UV-visible spectrophotometry of thin films showed that the films have an optical transmission above 80 % in the visible and the values of Eg were in the range 3.98-4.02 eV.

  5. Ethylene glycol assisted spray pyrolysis for the synthesis of hollow BaFe12O19 spheres

    Energy Technology Data Exchange (ETDEWEB)

    Xu, X; Park, J; Hong, YK; Lane, AM

    2015-04-01

    Hollow spherical BaFe12O19 particles were synthesized by spray pyrolysis from a solution containing ethylene glycol (EG) and precursors at 1000 degrees C. The effects of EG concentration on particle morphology, crystallinity and magnetic properties were investigated. The hollow spherical particles were found to consist of primary particles, and higher EG concentration led to a bigger primary particle size. EG concentration did not show much effect on the hollow particle size. Better crystallinity and higher magnetic coercivity were obtained with higher EG concentration, which is attributed to further crystallization with the heat produced from EG combustion. Saturation magnetization (emu/g) decreased with increasing EG concentration due to residual carbon from EG incomplete combustion, contributing as a non-magnetic phase to the particles. Published by Elsevier B.V.

  6. Characterization and Gas Sensing Properties of Copper-doped Tin Oxide Thin Films Deposited by Ultrasonic Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Zhaoxia ZHAI

    2016-05-01

    Full Text Available Tin oxide-based thin films are deposited by ultrasonic spray pyrolysis technology, in which Cu addition is introduced to enhance the gas sensing performance by H2S detection. The thin films are porous and comprise nano-sized crystallites. One of the Cu-containing thin film sensors demonstrates a fast and significant response to H2S gas. The values of power law exponent n are calculated to discuss the sensitivity of the sensors, which is significantly promoted by Cu additive. The sensitivity of Cu-doped SnO2 gas sensors is determined by two mechanisms. One is the normal gas sensing mechanism of SnO2 grains, and the other is the promoted mechanism caused by the transformation between CuO and CuS in the H2S detection. DOI: http://dx.doi.org/10.5755/j01.ms.22.2.12917

  7. Effect of In doping on the properties and antibacterial activity of ZnO films prepared by spray pyrolysis.

    Science.gov (United States)

    Manoharan, C; Pavithra, G; Dhanapandian, S; Dhamodharan, P

    2015-10-01

    Pure and In-doped ZnO thin films were deposited onto glass substrates by spray pyrolysis technique. XRD results showed that all films were polycrystalline in nature with the wurzite structure. A change in preferential orientation from (002) to (101) plane was observed with increase in content of Indium. A reduce in crystallite size was observed with increase of In content. The small sized grains with the porous nature of the film was observed from SEM analysis. AFM study depicted polycrystalline nature and uniformly distributed grains with small pores in the doped film. A decrease in band gap was noticed with increase in In content. The absence of green emission in PL spectra indicated the decreased oxygen defects. The decrease in the resistivity with increase of Hall mobility was noted for the doped film. A better antibacterial activity was observed against Staphylococcus aureus by doped ZnO thin film. PMID:25997176

  8. One-step synthesis of bismuth molybdate catalysts via flame spray pyrolysis for the selective oxidation of propylene to acrolein.

    Science.gov (United States)

    Schuh, K; Kleist, W; Høj, M; Trouillet, V; Jensen, A D; Grunwaldt, J-D

    2014-12-18

    Flame spray pyrolysis (FSP) of Bi(III)- and Mo(VI)-2-ethylhexanoate dissolved in xylene resulted in various nanocrystalline bismuth molybdate phases depending on the Bi/Mo ratio. Besides α-Bi2Mo3O12 and γ-Bi2MoO6, FSP gave direct access to the metastable β-Bi2Mo2O9 phase with high surface area (19 m(2) g(-1)). This phase is normally only obtained at high calcination temperatures (>560 °C) resulting in lower surface areas. The β-phase was stable up to 400 °C and showed superior catalytic performance compared to α- and γ-phases in selective oxidation of propylene to acrolein at temperatures relevant for industrial applications (360 °C). PMID:25350295

  9. Effect of tin doping on optical properties of nanostructured ZnO thin films grown by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Bedia, F.Z.; Bedia, A. [URMER, Abou-Bakr Belkaid University, 13000 Tlemcen (Algeria); Maloufi, N., E-mail: nabila.maloufi@univ-lorraine.fr [Laboratoire d’Étude des Microstructures et de Mécanique des Matériaux (LEM3), UMR-CNRS 7239, Université de Lorraine, 57045 Metz (France); Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Université de Lorraine (France); Aillerie, M.; Genty, F. [LMOPS-EA 4423, Université de Lorraine, 57070 Metz (France); Supelec, LMOPS, 57070 Metz (France); Benyoucef, B. [URMER, Abou-Bakr Belkaid University, 13000 Tlemcen (Algeria)

    2014-12-15

    Highlights: • (0–2%) Sn-doped ZnO films grown by spray pyrolysis on glass substrates. • Transmittance up to 93% in visible region, sharp absorption edge at 360 nm. • Blue shift of optical band gap: E{sub g} = 3.27 eV for 0% Sn; Eg{sub max} = 3.30 eV for 0.5% Sn. • All the optical parameters reach threshold values for 0.5% Sn-doped ZnO films. • Good physical properties suited for films integration in optoelectronic devices. - Abstract: Sn-doped ZnO thin films with 0%, 0.5%, 1%, 1.5% and 2% Sn were grown by spray pyrolysis method on glass substrates under optimized conditions. High resolution Field Effect Scanning Electron Microscopy characterization showed that the films consist of hexagonal-like grains. A comprehensive study of the optical properties was performed and the dispersion constants were determined. The effect of Sn content on the optical band gap and the optical constants (refractive index, extinction coefficient, dielectric constants, and dispersion parameters) was studied. These Sn-doped ZnO thin films are highly transparent (73–93%) in the visible region. A blue shift of the optical band gap, attributed to the Burstein Moss effect, was observed for the Sn-doped films. All the optical dispersion parameters depend on the Sn content of the films, but were found to reach threshold values at a Sn content of 0.5%. These optical parameters are discussed in terms of the single oscillator model. This study demonstrated that this 0.5% Sn-doped ZnO thin film has enhanced physical properties, allowing its better integration in optoelectronic devices.

  10. Core–shell-structure Ag–BaTiO{sub 3} composite nanopowders prepared directly by flame spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seung Ho; Ko, You Na; Lee, Jung-Kul [Department of Chemical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of); Park, Byung Kyu [Suncheon Center, Korea Basic Science Institute, Suncheon 540-742 (Korea, Republic of); Kang, Yun Chan, E-mail: yckang@konkuk.ac.kr [Department of Chemical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)

    2013-06-15

    Core–shell-structure Ag–BaTiO{sub 3} composite nanopowders are prepared directly by flame spray pyrolysis. The single-crystalline Ag was located in the core part of the composite powder, and the Ba and Ti components are uniformly distributed in the shell part. The X-ray diffraction (XRD) patterns of the Ag–BaTiO{sub 3} composite powders have the main crystal peaks of Ag and broad peaks at around 28°. The Ag–BaTiO{sub 3} pellets with low Ag contents (below 20 wt%) have a dense structure and fine grain size. Abnormal grain growth of the Ag(30 wt%)–BaTiO{sub 3} pellets occurs even at a low sintering temperature of 1000 °C. The Ag–BaTiO{sub 3} pellet had a mixed crystal structure of BaTiO{sub 3} and Ag phases. Silver is uniformly distributed in the BaTiO{sub 3} matrix without phase separation. The dielectric constants of the BaTiO{sub 3}, Ag(10 wt%)–BaTiO{sub 3}, and Ag(30 wt%)–BaTiO{sub 3} pellets are 830, 2130, and 4680, respectively. - Highlights: • Core–shell-structure Ag–BaTiO{sub 3} nanopowders are prepared by flame spray pyrolysis. • The single-crystalline Ag is located in the core part of the composite nanopowders. • The dielectric constant of the Ag(30 wt%)–BaTiO{sub 3} pellet is high as 4680.

  11. Synthesis of Al{sub 2}O{sub 3} thin films using laser assisted spray pyrolysis (LASP)

    Energy Technology Data Exchange (ETDEWEB)

    Dhonge, Baban P. [Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102 TN (India); Mathews, Tom, E-mail: tom@igcar.gov.in [Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102 TN (India); Tripura Sundari, S.; Krishnan, R.; Balamurugan, A.K.; Kamruddin, M. [Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102 TN (India); Subbarao, R.V. [Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102 TN (India); Dash, S.; Tyagi, A.K. [Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102 TN (India)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Alumina thin films were made by laser assisted spray pyrolysis at various laser powers. Black-Right-Pointing-Pointer The particle size was found to increase with laser power. Black-Right-Pointing-Pointer The refractive index of the films was studied using ellipsometry. Black-Right-Pointing-Pointer The film stoichiometry was studied using X-ray photoelectron spectroscopy. Black-Right-Pointing-Pointer The film/substrate interface was studied using ellipsometer and secondary ion mass spectrometer. - Abstract: The present study reports the development of a laser assisted ultrasonic spray pyrolysis technique and synthesis of dense optical alumina films using the same. In this technique ultrasonically generated aerosols of aluminum acetylacetonate dissolved in ethanol and a laser beam (Nd:YAG, CW, 1064 nm) were fed coaxially and concurrently through a quartz tube on to a hot substrate mounted on an X-Y raster stage. At the laser focused spot the precursor underwent solvent evaporation and solute sublimation followed by precursor vapor decomposition giving rise to oxide coating, the substrate is rastered to get large surface area coating. The surface morphology revealed coalescence of particles with increase in laser power. The observed particle sizes were 17 nm for films synthesized without laser and 18, 21 and 25 nm for films made with laser at 25, 38 and 50 W, respectively. Refractive index of the films synthesized increased from 1.56 to 1.62 as the laser power increased from 0 to 50 W. The stoichiometry of films was studied using XPS and the increase in interfacial layer thickness with laser power was observed from dynamic SIMS depth profiling and ellipsometry.

  12. Electrochemical properties of yolk-shell structured layered-layered composite cathode powders prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Graphical abstract: - Abstract: Layered-layered yolk-shell powders with composition 0.6Li(Li1/3Mn2/3)O2· 0.4Li(Ni1/3Co1/3Mn1/3)O2 are prepared by spray pyrolysis. Metal oxides-carbon composite powders are first formed as an intermediate product near the reactor entrance by drying and decomposition of droplets. Combustion, contraction, and recombustion processes of intermediate product produce yolk-shell-structured powders. The yolk-shell structure of the powders prepared directly by spray pyrolysis is maintained even after post-treatment at 800 °C; this treatment temperature yields the best electrochemical performance. The composition of the powders post-treated at 800 °C is Li1.12Ni0.14Co0.14Mn0.59O2. Mean grain sizes of the yolk-shell 0.6Li(Li1/3Mn2/3)O2·0.4Li(Ni1/3Co1/3Mn1/3)O2 powders, post-treated at 700, 750, and 800 °C, measured from high resolution TEM images, are 47, 54, and 79 nm, respectively, and their BET surface areas are 14, 9, and 7 m2 g−1. The initial discharge capacities of the powders, post-treated at the above temperatures, are 188, 280, and 239 mA h g−1, respectively, and their initial Coulombic efficiencies are 87, 80, and 78%. Discharge capacities after 50 cycles of the post-treated powders are 81, 194, and 183 mA h g−1, respectively, and the corresponding capacity retentions are 43, 70, and 77%

  13. Synthesis of conducting Zn1-xMgxO: Al layers by spray pyrolysis for photovoltaic application

    International Nuclear Information System (INIS)

    In recent years, Zn1-xMgxO has attracted the attention of many researchers as its physical behavior can be suitably controlled by varying the Zn/Mg ratio. Also, it has high stability with low toxicity and the abundance of constituent elements. Further, the band offsets can be tuned to a minimum level with respect to a heterojunction partner by suitably controlling the Zn/Mg ratio. These properties make this material as a potential candidate as a buffer layer in the fabrication of Cu(In,Ga)Se2-based solar cells. In our previous study, Zn1-xMgxO films prepared by spray pyrolysis at 300 deg. C have shown high resistance and optical transmittance with wide energy band gap. However, it is interesting to note that if the films were conducting, then they can also be used as window layers. In the present investigation, Zn0.76Mg0.24O films have been prepared by spray pyrolysis at an optimized substrate temperature of 300 deg. C with different dopant concentrations that vary in the range, 0-6%. X-ray diffraction analysis showed that the films were polycrystalline and exhibited wurtzite crystal structure with a preferential c-axis orientation. The influence of Al doping on the electrical resistivity was found to be significant. The average transmittance of the films was found to be > 60% in the visible range with a small variation in the optical energy band gap. The changes occurred in the structure, topography, composition, electrical and optical properties of the layers as a function of dopant concentration have been studied.

  14. Effect of tin doping on optical properties of nanostructured ZnO thin films grown by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Highlights: • (0–2%) Sn-doped ZnO films grown by spray pyrolysis on glass substrates. • Transmittance up to 93% in visible region, sharp absorption edge at 360 nm. • Blue shift of optical band gap: Eg = 3.27 eV for 0% Sn; Egmax = 3.30 eV for 0.5% Sn. • All the optical parameters reach threshold values for 0.5% Sn-doped ZnO films. • Good physical properties suited for films integration in optoelectronic devices. - Abstract: Sn-doped ZnO thin films with 0%, 0.5%, 1%, 1.5% and 2% Sn were grown by spray pyrolysis method on glass substrates under optimized conditions. High resolution Field Effect Scanning Electron Microscopy characterization showed that the films consist of hexagonal-like grains. A comprehensive study of the optical properties was performed and the dispersion constants were determined. The effect of Sn content on the optical band gap and the optical constants (refractive index, extinction coefficient, dielectric constants, and dispersion parameters) was studied. These Sn-doped ZnO thin films are highly transparent (73–93%) in the visible region. A blue shift of the optical band gap, attributed to the Burstein Moss effect, was observed for the Sn-doped films. All the optical dispersion parameters depend on the Sn content of the films, but were found to reach threshold values at a Sn content of 0.5%. These optical parameters are discussed in terms of the single oscillator model. This study demonstrated that this 0.5% Sn-doped ZnO thin film has enhanced physical properties, allowing its better integration in optoelectronic devices

  15. Effect of precursor concentration on structural and optical properties of ZnO microrods by spray pyrolysis

    International Nuclear Information System (INIS)

    ZnO films have been prepared by spray pyrolysis technique on glass substrate at 500 °C. Zinc Chloride has been used as a precursor. Effect of precursor concentration on structural and optical properties has been investigated. Homogenous films are obtained with precursor concentration rating between 0.1 M and 0.4 M. X-ray diffraction patterns show that ZnO films are polycrystalline with (002) plane as preferential orientation. Field emission scanning electron microscopy images show that ZnO films consist of microrods that their length increases with increasing precursor concentration and tallest microrods obtain by spraying precursor with 0.3 M concentration. The optical transmittance spectrum shows that transmittance increases with decreasing of the concentration and transmittance reaches to a maximum value of about 80% for the visible region ZnO films prepared with 0.1 M. Photoluminescence spectra at room temperature show an ultraviolet emission at 3.21 eV that can be related to band gap and two visible emissions at 2.88 eV and 2.38 eV.

  16. Electrical and optical properties of ZnO:Al thin films prepared by the spray pyrolysis technique

    International Nuclear Information System (INIS)

    Highly transparent conducting ZnO:Al thin films have been produced by the spray pyrolysis technique on glass substrates at a substrate temperature Ts=450 deg. C by a home-made spraying system. The electrical and optical properties of the films were investigated at room temperature before and after annealing in nitrogen atmosphere. The electrical properties were studied by recording and analyzing the I-V measurements. All the curves were linear, so the resistivity was estimated from the slopes. The resistivity was found to be 133 Ω cm for the undoped ZnO films, but 90 Ω cm for the Al-doped films before annealing and 84 Ω cm after annealing. The optical properties were investigated by measuring the transmittance curves that were used to find the optical bandgap energy. The bandgap energy was found to be 3.27 eV for the undoped ZnO films and 3.28 eV for the Al-doped ZnO films before and after annealing. Therefore the electro-optical properties of the films had improved with Al doping and annealing in nitrogen atmosphere.

  17. Deposition and characterization of graded Cu(In{sub 1-x}Ga{sub x})Se{sub 2} thin films by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Babu, B.J. [Department of Electrical Engineering-SEES, CINVESTAV-IPN, Avenida IPN 2508, San Pedro Zacatenco, D.F. C.P 07360 (Mexico); Institute of Molecules and Materials, UMR-CNRS 6283, Université du Maine, Avenue O. Messiaen, F-72085 Le Mans (France); Velumani, S., E-mail: velu@cinvestav.mx [Department of Electrical Engineering-SEES, CINVESTAV-IPN, Avenida IPN 2508, San Pedro Zacatenco, D.F. C.P 07360 (Mexico); College of Information and Communication Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kassiba, A. [Institute of Molecules and Materials, UMR-CNRS 6283, Université du Maine, Avenue O. Messiaen, F-72085 Le Mans (France); Asomoza, R. [Department of Electrical Engineering-SEES, CINVESTAV-IPN, Avenida IPN 2508, San Pedro Zacatenco, D.F. C.P 07360 (Mexico); Chavez-Carvayar, J.A. [Instituto Investigaciones en Materiales-UNAM, Ciudad Universitario, D.F.Mexico (Mexico); Yi, Junsin, E-mail: yi@yurim.skku.ac.kr [College of Information and Communication Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-07-15

    Cu(In{sub 1-x}Ga{sub x})Se{sub 2} (CIGS) thin films and their graded (x = 1 to 0) layer were grown on soda lime glass substrates using chemical spray pyrolysis (CSP) at different substrate temperatures (T{sub s}). After optimization of T{sub s}, depositions were carried out at different gallium composition (x) at optimized temperature of 350 °C. All the films deposited at T{sub s} ≥ 350 °C were polycrystalline chalcopyrite structure, with a preferential orientation of (112), including the graded layer. With increase in x, lattice parameters a and c were observed to decrease. Line scan of the CIGS layer showed intersection of gallium and indium concentrations, revealing the graded nature of the film. Composition dependence of Raman peak for CuInSe{sub 2} (CIS) deposited by CSP was analyzed. Optical transmittance at a wavelength of 800 nm of the film with x = 0 (CIS) (30%) was found lower than that of the film grown with x = 0.82 (CIGS) (50%). Cusp-shape of the resistivity was observed with an increase of x leading to steep rise in resistivity of the films (1.61–71.68 Ω-cm) till x = 0.42 and then decreased to 4.78 Ω-cm at x = 0.82. Carrier concentrations of the films were evaluated in the order of 10{sup 16}–10{sup 19} cm{sup −3} with p-type conductivity. These results indicate that graded CIGS thin films with modulated gallium composition can be prepared by CSP. - Graphical abstract: Display Omitted - Highlights: • Optimization of the spray deposition system for device grade chalcopyrite CIGS films. • Optimized substrate temperature to obtain single-phase CIGS by spray deposition. • Detailed report on compositional dependence of CuInSe{sub 2} (CIS) thin films. • Systematic analysis of the influence of Ga in CIS by spray deposition. • Bowing parameter is extracted from the experiment values.

  18. Temperature dependence of the photoluminescence spectra of CdS: In thin films prepared by the spray pyrolysis technique

    International Nuclear Information System (INIS)

    Indium doped cadmium sulfide thin films (CdS:In) are prepared by the spray pyrolysis technique on glass substrates using a home-made spraying system at a substrate temperature Ts=490 °C. The photoluminescence (PL) spectra are recorded at different temperatures in the range 24–160 K. Two broad peaks were observed; a strong one in the visible region centered on E≈2.0 eV and a weak one in the infrared region centered on E≈1.06 eV. The first one is deconvoluted into two Gaussian peaks corresponding to the yellow and red bands, and the second one is deconvoluted into one Gaussian peak corresponding to the infrared band. A strong quenching of the PL intensity with temperature is observed after T=60 K for the yellow and infrared bands and after T=90 K for the red band. The activation energy Ea was estimated by using the Arrhenius plot for the different bands. The estimated values for the three bands lie in the range Ea≈23.4–27.3 meV. The peak positions of the yellow and red bands are red-shifted after T=90 K, while the peak position of the infrared band is blue shifted in the whole temperature range. The full width at half maximum (FWHM) for the three bands increases with temperature. According to these findings the three bands are explained in terms of bound excitons. -- Highlights: • The photoluminescence (PL) of sprayed CdS:In thin films is recorded at different temperatures. • The PL spectrum is deconvoluted to three Gaussian peaks corresponding to yellow, red and infrared bands. • The decrease of the PL intensity with temperature for these bands has similar behaviors. • The yellow and red bands are red-shifted with temperature, but the infrared band is blue-shifted. • From the Arrhenius plots the activation energy is estimated

  19. An electrothermal chemical technology for thermal spray coatings

    International Nuclear Information System (INIS)

    A new spray technology for producing hard-coatings, has been developed at the SOREQ Nuclear Research Center. The concept is based on the extensive experience accumulated at SOREQ in the course of the development of Electrothermal (ET), Electrothermal-Chemical (ETC) and Solid-Propellant Electrothermal-Chemical (SPETC) guns(r). High quality coatings may be obtained by thermal spraying powder particles onto a variety of substrates. Mature state-of-the-art technologies such as plasma spray, high velocity oxy fuel (HVOF) and detonation gun (D-Gun) are widely used for many applications. As each method has its own drawbacks there is a need for a combination of several parameters which cannot be achieved by any existing individual commercial technology. The method presented is oriented toward a high-quality, multi-step, high-throughput, easily programmable continuous coating process and relatively inexpensive technology. The combustion products of a solid or liquid propellant accelerate the powder particles of the coating material. A pulsed-plasma jet, provided by a confined capillary discharge, ignites the propellant and controls the combustion process. The powder particles are accelerated to velocities over 1000 m/s. Due to the very high carrier gas density, high velocity, high throughput and high powder consumption efficiency are obtained. The plasma jet enables control of the gas temperature and consequently influences the powder temperature

  20. A study on the sensing of NO{sub 2} and O{sub 2} utilizing ZnO films grown by aerosol spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Mhlongo, G.H., E-mail: gmhlongo@csir.co.za [DST/CSIR National Centre for Nanostructured Materials, Council for Scientific and Industrial Research, Pretoria 0001 (South Africa); Motaung, D.E. [DST/CSIR National Centre for Nanostructured Materials, Council for Scientific and Industrial Research, Pretoria 0001 (South Africa); Kortidis, I. [Transparent Conductive Materials Lab, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, 100N. Plastira str., Vassilika Vouton, 70013 Heraklion, Crete (Greece); Mathe, N.R. [DST/CSIR National Centre for Nanostructured Materials, Council for Scientific and Industrial Research, Pretoria 0001 (South Africa); Ntwaeaborwa, O.M.; Swart, H.C. [Department of Physics, University of the Free State, Bloemfontein ZA9300 (South Africa); Mwakikunga, B.W.; Ray, S.S. [DST/CSIR National Centre for Nanostructured Materials, Council for Scientific and Industrial Research, Pretoria 0001 (South Africa); Kiriakidis, G., E-mail: kiriakid@iesl.fort.gr [Transparent Conductive Materials Lab, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, 100N. Plastira str., Vassilika Vouton, 70013 Heraklion, Crete (Greece)

    2015-07-15

    The present paper addresses the preparation and characterization of ZnO nanostructured thin films obtained using aerosol spray pyrolysis method at different deposition periods. Aiming at understanding the chemical composition, structural and morphological properties of the samples, characterization was performed using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), atomic force microscopy (AFM) and focused ion beam scanning electron microscopy (FIB-SEM), respectively. Defect structures were characterized by photoluminescence (PL), Raman, and electron paramagnetic resonance (EPR) techniques. The purity and crystallinity of the deposited films with increasing growth time were confirmed from XRD studies supported by Raman studies. AFM and SEM revealed morphology transition from uniform small particles to rod-like structures fused together growing perpendicular to the surface with prolonged deposition time. Optical absorption analyses revealed the decrease in the optical band-gap energy from 3.38 to 3.27 eV with prolonged growth time. The dominant emission at 2.80 eV (445 nm) in the PL spectra signifies the presence of Zn{sub i} in the ZnO nanostructures which is shown to slightly decrease with an increase in growth time. EPR analyses revealed higher ferromagnetic (FM) signal for ZnO films grown for 20 min. Improved sensitivity to both NO{sub 2} and O{sub 2} was observed for ZnO nanostructured film grown for 20 min owing to higher Zn{sub i} and V{sub O} as compared to its counterpart. Film grown for longer periods showed a decrease on the FM and sensitivity due to reduced Zn{sub i} and V{sub O} defects induced by larger grain sizes. - Graphical abstract: Display Omitted - Highlights: • Nanostructured ZnO thin films were grown using spray pyrolysis at different growth periods. • Growth time variation led to significant changes in the film thickness and surface morphology. • The origin of the surface related defects emission is explained in detail

  1. Growth and characterization of nanostructured aerosol produced by diffusion flame and spray pyrolysis methods

    Science.gov (United States)

    Kim, Soo Hyung

    The present research is aimed at developing methods to characterize and study the growth of nano-particles and nano-structured materials. The thesis is divided into two parts. One part deals with the development of the tandem differential mobility analyzer (TDMA), which is the principal method used in this study to characterize the size and electrical charge of particles formed in a high temperature flame. The second part of the thesis deals with the formation of nano-structured materials with zeolite-type structures. The particles are characterized to determine their size, porosity and surface area. It is well known that nano-sized aerosol particles from combustion sources are charged. Even though the basic charging mechanisms are reasonably well understood qualitatively, techniques for characterizing the charge and size distribution of aerosols from combustion sources are not well developed. In the present study, a method is developed to accurately measure the charge and size distribution of nano-sized combustion aerosols by means of a TDMA. From a series of TDMA measurements, the charge fraction of nano-sized soot particles from a flame is obtained as a function of equivalent mobility particle diameter ranging from 50 to 200nm. The method is then used to characterize the size and charge of combustion aerosols. The results are compared to theory, including the new theory developed in this study. To develop a new synthetic method of nano-structured aerosol particles, a thermal tubular reactor is employed. New spray-pyrolytic and aerosol-gel methods are developed to form nanoporous metal oxides, in which thermally stable and easily leached inorganic matrix is employed to extend the porosity of zeolite-typed materials. The characteristics of the nanoporous material, such as surface area and particle morphology are investigated as a function of relative humidity, temperature, and precursor fractions. The physical and chemical properties of materials synthesized are

  2. Metal-insulator transition characteristics of vanadium dioxide thin films synthesized by ultrasonic nebulized spray pyrolysis of an aqueous combustion mixture

    Science.gov (United States)

    Bharathi, R.; Naorem, Rameshwari; Umarji, A. M.

    2015-08-01

    We report the synthesis of high quality vanadium dioxide (VO2) thin films by a novel spray pyrolysis technique, namely ultrasonic nebulized spray pyrolysis of aqueous combustion mixture (UNSPACM). This simple and cost effective two step process involves synthesis of a V2O5 film on an LaAlO3 substrate followed by a controlled reduction to form single phase VO2. The formation of M1 phase (P21/c) is confirmed by Raman spectroscopic studies. A thermally activated metal-insulator transition (MIT) was observed at 61 ^\\circ C, where the resistivity changes by four orders of magnitude. Activation energies for the low conduction phase and the high conduction phase were obtained from temperature variable resistance measurements. The infrared spectra also show a dramatic change in reflectance from 13% to over 90% in the wavelength range of 7-15 μ m. This indicates the suitability of the films for optical switching applications at infrared frequencies.

  3. Nb-doped TiO2/carbon composite supports synthesized by ultrasonic spray pyrolysis for proton exchange membrane (PEM) fuel cell catalysts

    Science.gov (United States)

    Senevirathne, Keerthi; Neburchilov, Vladimir; Alzate, Vanesa; Baker, Ryan; Neagu, Roberto; Zhang, Jiujun; Campbell, Stephen; Ye, Siyu

    2012-12-01

    In this paper we report the use of both ultrasonic spray pyrolysis and microwave-assisted polyol reduction methods to synthesize Nb-doped TiO2/carbon (25 wt% Nb0.07Ti0.93O2/75 wt% carbon) composite supports and Pt0.62Pd0.38 alloy catalysts, respectively. The physicochemical properties of the synthesized supports and their Pt0.62Pd0.38 supported catalysts are evaluated using several methods including XRD, TEM, BET surface area analysis, TGA, as well as ICP-MS elemental analysis. The electronic conductivities and thermal/chemical stabilities of the supports are also evaluated with respect to their possible use as catalyst supports. Electrochemical measurements for oxygen reduction activity of the Pt0.62Pd0.38 alloy catalysts supported on oxide/carbon composites are also carried out in order to check their suitability for possible PEM fuel cell applications. The results show that 20wt%Pt0.62Pd0.38/25 wt%(Nb0.07Ti0.93O2)-75 wt%C catalysts exhibit enhanced mass activities compared to those of commercially available 48wt% Pt/C and home-made 20wt% Pt62Pd38/C catalysts.

  4. Structural and luminescent properties of europium doped TiO{sub 2} thick films synthesized by the ultrasonic spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Zaleta-Alejandre, E; Zapata-Torres, M; Aguilar-Frutis, M; Alarcon-Flores, G; Guzman-Mendoza, J [Centro de Investigacion en Ciencia Aplicada y TecnologIa Avanzada-IPN, Legaria 694, Col. Irrigacion, Del. Miguel Hidalgo, Mexico D.F. (Mexico); Garcia-Hipolito, M [Instituto de Investigaciones en Materiales-Universidad Nacional Autonoma de Mexico, A.P. 70-360, Coyoacan 04510, Mexico D.F. (Mexico); Falcony, C, E-mail: ezaletaa@ipn.m [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo. Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico)

    2009-05-07

    The structural and luminescent properties of trivalent europium-doped titanium dioxide films synthesized by the ultrasonic spray pyrolysis technique at several substrate temperatures are reported. These films are nanocrystalline and present a mixture of tetragonal (anatase and rutile) crystal structures of the titania as determined by x-ray diffraction. The rutile crystal structure became predominant as the substrate temperature during deposition was increased. Under UV and electron beam excitation, these coatings showed strong luminescence due to f-f transitions and the dominant transition was the hypersensitive {sup 5}D{sub 0} {yields} {sup 7}F{sub 2} red emission of Eu{sup 3+}. The photo- and cathodoluminescence characteristics of these films were studied as a function of growth parameters such as substrate temperature and europium concentration. Excitation with a wavelength of 396 nm resulted in photoluminescent emission peaks located at 557, 580, 592, 615, 652 and 703 nm, associated with the electronic transitions of the Eu{sup 3+} ion. The photoluminescence (PL) intensity as a whole is observed to decrease as the deposition temperature is increased. Also, with increasing doping concentration, a quenching of the PL is observed. The chemical composition and surface morphology characteristics of the films are also reported.

  5. Violet-blue luminescence from hafnium oxide layers doped with CeCl{sub 3} prepared by the spray pyrolysis process

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Hipolito, M.; Alvarez-Fragoso, O.; Alvarez-Perez, M.A.; Martinez-Martinez, R. [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico (Mexico); Caldino, U. [Universidad Autonoma Metropolitana, Iztapalapa, Mexico DF (Mexico); Falcony, C. [Departamento de Fisica, CINVESTAV-IPN, Mexico (Mexico)

    2007-07-15

    HfO{sub 2}:CeCl{sub 3} coatings were deposited by the spray pyrolysis method employing hafnium dichloride oxide and CeCl{sub 3} dissolved in deionized water (18 M{omega}/cm). The room temperature photoluminescence characteristics of the HfO{sub 2}:CeCl{sub 3} films were studied as a function of the deposition parameters such as doping concentrations and substrate temperature. The presence of two different Ce{sup 3+} centres in HfO{sub 2} is detected from photoluminescence measurements. A reduction of the luminescence intensity is observed with an increase of both the CeCl{sub 3} concentration and the deposition temperature. X-ray diffraction measurements of these films showed that the crystalline structure depends on the substrate temperature. For substrate temperatures less than 350 C the deposited films are almost amorphous, while substrate temperatures higher than 400 C produce diffraction peaks corresponding to the monoclinic phase of HfO{sub 2}. The chemical composition of the films as determined by energy dispersive spectroscopy is also reported. Furthermore, the surface morphology characteristics of the coatings, as a function of the deposition temperature, are also presented. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Polymer and surfactant-templated synthesis of hollow and porous ZnS nano- and microspheres in a spray pyrolysis reactor.

    Science.gov (United States)

    Sharma, Munish K; Rohani, Parham; Liu, Sha; Kaus, Mark; Swihart, Mark T

    2015-01-13

    Nanostructured zinc sulfide can provide unique photonic, electronic, and catalytic properties that are of interest for applications ranging from bioimaging to photocatalysis. Here we report an easily controllable continuous method to produce porous and hollow ZnS nano- and microspheres. We used poly(ethylene glycol) methyl ether (PEG), polyvinylpyrrolidone (PVP), ethylene oxide/propylene oxide block copolymer (Pluronic F-38), and cetyltrimethylammonium bromide (CTAB) as templates to synthesize ZnS nano- and microspheres with controlled internal morphology in a spray pyrolysis process, starting from an aqueous solution of chemical precursors and templating agents. Spherical particles were produced by droplet-to-particle conversion of droplets. Zinc acetate and thiourea, used here as precursors for ZnS, react in solution to form bis-thiourea zinc acetate (BTZA), which precipitates with the evaporation of solvent. Upon further heating, BTZA decomposes to yield ZnS. During solvent evaporation, PEG and Pluronic precipitate after BTZA, driving formation of a shell of ZnS and a hollow core. In contrast, PVP and CTAB interact strongly with BTZA and ZnS, such that the PVP and ZnS remain intermixed. After evaporation of solvent, the templating agents can be pyrolyzed at high temperature to leave behind porous or hollow ZnS microspheres composed of many much smaller nanocrystals. PMID:25547202

  7. Mass Production of LiFePO4/C Powders by Large Type Spray Pyrolysis Apparatus and Its Application to Cathode for Lithium Ion Battery

    Directory of Open Access Journals (Sweden)

    Shinsuke Akao

    2010-01-01

    Full Text Available Spherical LiFePO4/C powders were successfully produced at a rate of 100 g/h using a large type spray pyrolysis apparatus. Organic compounds such as citric acid and sucrose were used as carbon sources. Scanning electron microscopy observation showed that they had a spherical morphology with nonaggregation. X-ray diffraction analysis revealed that the olivine phase was obtained by heating at 600∘C under argon (95%/hydrogen (5% atmosphere. The chemical composition of LiFePO4/C powders was in good agreement with that of the starting solution. Electrochemical measurement revealed that the use of citric acid was most effective in ensuring a high rechargeable capacity and cycle stability. The rechargeable capacity of the LiFePO4/C cathode obtained using citric acid was 155 mAh/g at a discharge rate of 1 C. Because of the good discharge capacity of the LiFePO4/C cathode, it exhibited excellent cycle stability after 100 cycles at each discharge rate. Moreover, this high cycle stability of the LiFePO4/C cathode was maintained even at 50∘C.

  8. Effect of F doping on physical properties of (211) oriented SnO2 thin films prepared by jet nebulizer spray pyrolysis technique

    Science.gov (United States)

    Thirumoorthi, M.; Prakash, J. Thomas Joseph

    2016-01-01

    Transparent conducting fluorine doped tin oxide (FTO) thin films have been prepared jet nebulizer spray pyrolysis technique at 500 °C for different doping concentrations. The X-ray diffraction spectra confirm the polycrystalline nature of SnO2: F with tetragonal structure. All the films show a preferred growth orientation along (211) diffraction plane. Scanning electron microscope images show that the films have a uniform surface morphology with well defined pyramid like grains. The AFM results of the films indicate that the surface roughness is increased with F doping. The optical transmittance of FTO films is improved from 75 to 92% in the visible region of the solar spectrum and the optical absorption of the films is very low. The blue shift of optical band of the films is explained by Burstain-Mass effect. The observed blue shift of the UV emission band in the photoluminescence spectra confirms the incorporation of F into tin oxide crystal lattice. The presence of functional groups and chemical bonding were confirmed by FTIR. Hall Effect measurements show that the prepared films having n-type conductivity with low resistivity (2.3 × 10-4 Ω-cm) and high carrier concentrations (6.9 × 1020 cm-3).

  9. Thin Film Electrode Materials Li4Ti5O12 and LiCoO2 Prepared by Spray Pyrolysis Method

    International Nuclear Information System (INIS)

    The Li4Ti5O12 and the LiCoO2 have been considered as promising candidates of electrode materials for all-solid-state lithium secondary batteries. The spray pyrolysis method is a useful economical technique to prepare various thicknesses of oxide films though have not been intensively studied for fabrication of thin film lithium batteries. Thin films of Li4Ti5O12 and LiCoO2 electrode materials about 100-400 nm were prepared on quartz and gold substrates by the spray pyrolysis method by using Liacac and, TiO(acac)4 or Co(acac)3 with DMF solvent as starting materials. Electric properties as electrode materials for lithium batteries were estimated by using 3 probe liquid cells with liquid electrolyte LiPF6 in EC-DMC and Li metal as reference and counter electrodes. Structure and morphology of the films were investigated by XRD and SEM. Crystalline Li4Ti5O12 and LiCoO2 thin films were found to be prepared over 700 deg. C of substrate temperature. Cyclic voltammograms of the Li4Ti5O12 electrode thin films showed sharp oxidation and reduction peaks around 1.6 and 1.5 V, respectively. Charge-discharge curves for both Li4Ti5O12 and LiCoO2 electrode thin films showed discharge plateaus around 1.4 and 3.8 V with about 80 mAhg-1 of capacity. These results showed that these electrode thin films prepared by the spray pyrolysis method are electrochemically active and spray pyrolysis method is a promising technique to prepare thin film electrode materials.

  10. Synthesis of hollow cobalt oxide nanopowders by a salt-assisted spray pyrolysis process applying nanoscale Kirkendall diffusion and their electrochemical properties.

    Science.gov (United States)

    Ju, Hyeon Seok; Cho, Jung Sang; Kim, Jong Hwa; Choi, Yun Ju; Kang, Yun Chan

    2015-12-21

    A new concept for preparing hollow metal oxide nanopowders by salt-assisted spray pyrolysis applying nanoscale Kirkendall diffusion is introduced. The composite powders of metal oxide and indecomposable metal salt are prepared by spray pyrolysis. Post-treatment under a reducing atmosphere and subsequent washing using distilled water produce aggregation-free metal nanopowders. The metal nanopowders are then transformed into metal oxide hollow nanopowders by nanoscale Kirkendall diffusion. Co3O4 hollow nanopowders are prepared as first target materials. A cobalt oxide-NaCl composite powder prepared by spray pyrolysis transforms into several Co3O4 hollow nanopowders by several treatment processes. The discharge capacities of the Co3O4 nanopowders with filled and hollow structures at a current density of 1 A g(-1) for the 150th cycle are 605 and 775 mA h g(-1), respectively. The hollow structure formed by nanoscale Kirkendall diffusion improves the lithium-ion storage properties of Co3O4 nanopowders. PMID:26571144

  11. Influences of alcoholic solvents on spray pyrolysis deposition of TiO2 blocking layer films for solid-state dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Influences of alcoholic solvents for titanium diisopropoxide bis(acetylacetonate) (TPA) precursor solutions on the spray pyrolysis deposited TiO2 films and the photovoltaic performance of the solid-state dye-sensitized solar cells (SDSCs) using these TiO2 films as the blocking layers were investigated. Smooth TiO2 films were obtained by spray pyrolysis deposition of a TPA solution in isopropanol (IPA) at a relatively low temperature of 260 °C. On the other hand, when ethanol was used as solvent, the TiO2 films fabricated at the same temperature showed much rougher surfaces with many pinholes. Our results showed that ethanol reacts with TPA to form titanium diethoxide bis(acetylacetonate) (TEA), which requires a higher thermal decomposition temperature than that of TPA. SDSCs with TiO2 blocking layer films fabricated using a TPA solution in IPA showed higher power conversion efficiencies with smaller variations. - Graphical abstract: Alcoholic solvents used for the TiO2 precursor play a critical role in determining the surface morphology of blocking layers and thus the photovoltaic performance of the SDSCs. Highlights: ► Solvent influences morphology of spray pyrolysis deposited TiO2 blocking layer. ► Ethanol reacts with TPA, resulting poor quality of blocking layer. ► Isopropanol is better than ethanol for obtaining smooth blocking layer. ► SDSC with blocking layer made with isopropanol showed better performance.

  12. Lignin Valorisation for Chemicals and (Transportation) Fuels via (Catalytic) Pyrolysis and Hydrodeoxygenation

    NARCIS (Netherlands)

    de Wild, Paul; Van der Laan, Ron; Kloekhorst, Arjan; Heeres, Hero

    2009-01-01

    New technology is needed to exploit the potential of lignin as a renewable feedstock for fuels, chemicals and performance products. Fast fluidized bed pyrolysis of different lignins at 400 degrees C yields up to 2.1 wt% (d.b.) of a phenolic fraction containing 10 wt%, (d.b.) of several phenols. Subs

  13. Structural and optical properties of ZnO–SnO{sub 2} mixed thin films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Tharsika, T., E-mail: tharsika@siswa.um.edu.my; Haseeb, A.S.M.A., E-mail: haseeb@um.edu.my; Sabri, M.F.M., E-mail: faizul@um.edu.my

    2014-05-02

    Nanocrystalline ZnO–SnO{sub 2} mixed thin films were deposited by the spray pyrolysis technique at various substrate temperatures during deposition. The mixed films were prepared in the range of 20.9 at.% to 73.4 at.% by altering the Zn/(Sn + Zn) atomic ratio in the starting solution. Morphology, crystal structures, and optical properties of the films were characterized by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and ultraviolet–visible and photoluminescence (PL) spectroscopy. XRD analysis reveals that the crystallinity of the Sn-rich mixed thin films increases with increasing substrate temperatures. FESEM images show that the grain size of mixed thin films is smaller compared to that of pure ZnO and SnO{sub 2} thin films. A drop in the thickness and optical bandgap of the film was observed for films fabricated at high temperatures, which coincided with the increased crystallinity of the films. The average optical transmission of mixed thin films increased from 70% to 95% within the visible range (400–800 nm) as the substrate temperature increases. Optical bandgap of the films was determined to be in the range of 3.21–3.96 eV. The blue shift in the PL spectra from the films was supported by the fact that grain size of the mixed thin films is much smaller than that of the pure ZnO and SnO{sub 2} thin films. Due to the improved transmission and reduced grain size, the ZnO–SnO{sub 2} mixed thin films can have potential use in photovoltaic and gas sensing applications. - Highlights: • ZnO–SnO{sub 2} mixed thin films were deposited on glass substrate by spray pyrolysis. • Crystallinity of the thin films increases with substrate temperature. • Grain size of the mixed thin films is smaller than that of the pure thin films. • Reduction of grain size depends on mixed atomic ratios of precursor solution. • Optical band gap of films could be engineered by changing substrate temperature.

  14. Fabrication and characterization of n-ZnO:Eu/p-ZnO:(Ag, N) homojunction by spray pyrolysis

    International Nuclear Information System (INIS)

    Graphical abstract: In this paper authors report the fabrication of ZnO homojunction by the deposition of 2 at.% Eu doped ZnO (n-ZnO:Eu) layer grown over the 4 at.% Ag–N dual acceptor doped ZnO (p-ZnO:(Ag, N)) layer by spray pyrolysis technique. The as-grown n-type and p-type ZnO films on glass substrates have been characterized by Hall measurements, X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), UV–vis and luminescence spectroscopy techniques. Hall measurement shows that 4 at.% ZnO:(Ag, N) film exhibits p-type conductivity with high hole concentration of 2.17 × 1018 cm−3 and n-type conductivity is observed in the ZnO:Eu film. The current–voltage characteristics measured from the two-layer structure show typical rectifying characteristics of p–n homojunction with a low turn on voltage of about 1.85 V. I–V characteristics of the n-ZnO:Eu/p-ZnO:(Ag, N) homojunction. - Highlights: • The n-ZnO:Eu/p-ZnO:(Ag, N) homojunction is fabricated and characterized. • Low resistive and stable p-type ZnO films are achieved by dual acceptor-doping. • Homojunction with best dual-doped ZnO film shows good rectifying characteristics. • The fabricated ZnO homojunction is suitable for optoelectronic devices. - Abstract: In the present study, the authors report the fabrication of ZnO homojunction by the deposition of 2 at.% Eu doped ZnO (n-ZnO:Eu) layer grown over the 4 at.% Ag–N dual acceptor doped ZnO (p-ZnO:(Ag, N)) layer by spray pyrolysis technique. The as-grown n-type and p-type ZnO films on glass substrates have been characterized by Hall measurements, X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), UV–vis and luminescence spectroscopy techniques. Hall measurement shows that 4 at.% ZnO:(Ag, N) film exhibits p-type conductivity with high hole concentration of 2.17 × 1018 cm−3 and n-type conductivity is observed in the ZnO:Eu film. The current–voltage characteristics measured from the two-layer structure show typical

  15. Synthesis of composite WO3/TiO2 nanoparticles by flame-assisted spray pyrolysis and their photocatalytic activity

    International Nuclear Information System (INIS)

    Highlights: • We synthesize composite WO3/TiO2 nanoparticles using spray pyrolysis method. • We varied the concentration of AMT and TTIP in wide range ratio (0–100 wt%). • Photodegradation drastically improvement when the ratio of AMT below than 25 wt%. • When the ratio of AMT of above 25 wt%, the photodegradation slightly improvement. • The changes of photodegradation rate are influenced by band gap energy and surface area. -- Abstracts: Combining of tungsten trioxide (WO3) with titanium dioxide (TiO2) have been an interesting research subject because different from conventional TiO2 material, this composite can be used and activated under visible-light irradiation and has better photocatalytic efficiency. The purpose of this study was to synthesize composite WO3/TiO2 nanoparticles and to investigate the detail effect of composition of ammonium metatungstate (AMT, as a WO3 source) and titanium isopropoxide (TTIP, as a TiO2 source) in the wide range composition ratio on particle morphology (i.e.,outer size (from 20 to 90 nm), shape, and structure), crystallinity, and photocatalytic performance. To synthesize composite WO3/TiO2 nanoparticles, a flame-assisted spray-pyrolysis method was used. Experimental results showed that the amount of AMT (from 0 to 25 wt%) had shown a significant impact on the photocatalytic performance, however deviation of this amount had improve catalyst performance slightly. The change of photocatalytic activity is mainly influenced by band gap energy and surface area. To confirm the fundamental reason for this catalytic improvement, the effect of WO3 and TiO2 amounts on surface area, light absorbance, and charge separation analysis was investigated. The experimental results were also completed along with the proposal photocatalytic mechanism of particles containing WO3 and TiO2. In addition, although our present photocatalytic activity still needs to be improved, the present results open new information for creating more varied

  16. Dye-sensitized solar cell based on optically transparent TiO2 nanocrystalline electrode prepared by atomized spray pyrolysis technique

    International Nuclear Information System (INIS)

    Highlights: → Transparent TiO2 films were prepared by the atomized spray pyrolysis method. → These films contain 3-5 nm discrete particles, interconnected to give a crack-free thin film structure. → Dye-absorption of the TiO2 film is 2.16 times higher than those used in conventional DSCs. → Conversion efficiency of 8.2% can be achieved with 1000 W m-2 irradiation. - Abstract: Preparation of crack-free thin films of interconnected and non-agglomerated TiO2 nanoparticles on electronically conducting fluorine doped tin oxide surfaces is instrumental in designing and developing transparent dye-sensitized solar cells (DSCs). A novel technique called 'Atomized Spray Pyrolysis' (ASP) has been designed and developed to achieve such perfectly transparent thin films. Optical transmittance of TiO2 films produced on FTO surface by this ASP method has been compared with those obtained by doctor-blading and by hand spray methods and found that the atomized spray pyrolysis technique give films with high transparency. Dye adsorption per gram of TiO2 is 2.16 times higher in the sample produced by the ASP method when compared to the film produced by the hand spray method and is 1.60 times higher than that produced by the doctor-blading method using a commercially available TiO2 nanocrystalline paste. SEM studies show the presence of interconnected discrete particles in the film produced by the ASP method. The fill factor (ff) remains almost constant for the cells with thickness from 6 μm to 13 μm but the highest photovoltage and photocurrent were found in ∼10 μm film based DSC which gave 8.2% conversion efficiency at AM 1.5 irradiation for cells of 0.25 cm2 active area.

  17. Investigations of superparamagnetism in magnesium ferrite nano-sphere synthesized by ultrasonic spray pyrolysis technique for hyperthermia application

    Energy Technology Data Exchange (ETDEWEB)

    Das, Harinarayan, E-mail: hn_das@yahoo.com [Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku Naka-ku, Hamamatsu 432-8561 (Japan); Materials Science Division, Atomic Energy Centre, Bangladesh Atomic Energy Commission, Dhaka 1000, Bangladesh (Bangladesh); Sakamoto, Naonori [Department of Electronics and Materials Science, Shizuoka University, 3-5-1 Johoku Naka-ku, Hamamatsu 432-8561 (Japan); Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku Naka-ku, Hamamatsu 432-8561 (Japan); Aono, Hiromichi [Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama 790-85770 (Japan); Shinozaki, Kazuo [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1 O-okayama Meguro-ku, Tokyo 152-8550 (Japan); Suzuki, Hisao; Wakiya, Naoki [Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku Naka-ku, Hamamatsu 432-8561 (Japan); Department of Electronics and Materials Science, Shizuoka University, 3-5-1 Johoku Naka-ku, Hamamatsu 432-8561 (Japan); Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku Naka-ku, Hamamatsu 432-8561 (Japan)

    2015-10-15

    In this paper, we present the synthesized of magnesium ferrite (MgFe{sub 2}O{sub 4}) nano-spheres by a single-step ultrasonic spray pyrolysis (USP) technique from the aqueous metal nitrate precursor solution without any organic additives or post-annealing processes. The effects of different pyrolysis temperatures on the particles size, morphology and their superparamagnetic behavior have been investigated to evaluate the heat generation efficiency in an AC magnetic field. The X-ray powder diffraction spectra of MgFe{sub 2}O{sub 4} nano-spheres synthesized at the pyrolysis temperatures of 600, 700, 800 and 900 °C exhibited single phase cubic structure and obtained mean crystallite size (primary particles) of 4.05, 9.6, 15.97 and 31.48 nm, respectively. Transmission electron microscopy (TEM) confirms that the particles consisted of aggregates of the primary crystallite had densely congested spherical morphology with extremely smooth surface appearance. Field emission electron microscopy (FESEM) reveals that the shape and size of the nano-spheres (secondary particles) does not change significantly but the degree of agglomeration between the secondary particles was reduced with increasing the pyrolysis temperature. The average size and size distribution of nano-spheres measured using electrophoretic scattering photometer have found very low polydispersity index (PDI) for all samples. The field dependent magnetization studies indicated superparamagnetic nature for the particles having crystallite size i.e. 4.05 and 9.6 nm and exhibited ferromagnetic nature for 15.97 and 31.48 nm. It is also demonstrated that, as the pyrolysis temperature increases, the saturation magnetization of the MgFe{sub 2}O{sub 4} nanopowders increases due to enhancement of crystallites. The shift in Curie temperature is well described by the finite-size scaling formula. The magnetically loss heating values of selected samples in crystallite size of 9.6 and 15.97 nm were investigated by measuring

  18. Numerical Simulation on the Device of Rare Earth Oxide Preparation by Rare Earth Chloride Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2015-01-01

    Full Text Available Based on the industrial applications of jet pyrolysis technology and it being used for the production of rare earth oxides, the paper hopes to find out an efficient, economic, and environmental friendly new technology which is suitable for production of rare earth oxides. In this paper, a chloride pyrolysis water model is designed, and standard κ-ε turbulence model and VOF model were coupled to simulate the three-dimensional steady gas-liquid flow in jet reactor. The valuable parameter we got provides strong basis for the experimental equipment manufacturing in thermal state and determining test program. Conclusions show that when the drainage tube diameter is 3 mm, it can guarantee that two-phase distribution of the gas-liquid is more uniform and easy for gas-liquid mixing in the tail region of the Venturi tube. If the fluid near the middle of the duct in front of the Venturi starts to reach equilibrium as constant speed flowing, it proves that elongated pipe is conducive to obtain a stable flow of air required by experiments. In the adjustable pipeline location of the Venturi tube, fluid can form a closed loop and generate reflux in the export where atomization and gas-liquid mixing have good effects.

  19. ZnO-based thin film transistors employing aluminum titanate gate dielectrics deposited by spray pyrolysis at ambient air.

    Science.gov (United States)

    Afouxenidis, Dimitrios; Mazzocco, Riccardo; Vourlias, Georgios; Livesley, Peter J; Krier, Anthony; Milne, William I; Kolosov, Oleg; Adamopoulos, George

    2015-04-01

    The replacement of SiO2 gate dielectrics with metal oxides of higher dielectric constant has led to the investigation of a wide range of materials with superior properties compared with SiO2. Despite their attractive properties, these high-k dielectrics are usually manufactured using costly vacuum-based techniques. To overcome this bottleneck, research has focused on the development of alternative deposition methods based on solution-processable metal oxides. Here we report the application of spray pyrolysis for the deposition and investigation of Al2x-1·TixOy dielectrics as a function of the [Ti(4+)]/[Ti(4+)+2·Al(3+)] ratio and their implementation in thin film transistors (TFTs) employing spray-coated ZnO as the active semiconducting channels. The films are studied by UV-visible absorption spectroscopy, spectroscopic ellipsometry, impedance spectroscopy, atomic force microscopy, X-ray diffraction and field-effect measurements. Analyses reveal amorphous Al2x-1·TixOy dielectrics that exhibit a wide band gap (∼4.5 eV), low roughness (∼0.9 nm), high dielectric constant (k ∼ 13), Schottky pinning factor S of ∼0.44 and very low leakage currents (<5 nA/cm(2)). TFTs employing stoichiometric Al2O3·TiO2 gate dielectrics and ZnO semiconducting channels exhibit excellent electron transport characteristics with low operating voltages (∼10 V), negligible hysteresis, high on/off current modulation ratio of ∼10(6), subthreshold swing (SS) of ∼550 mV/dec and electron mobility of ∼10 cm(2) V(-1) s(-1). PMID:25774574

  20. Yolk-shell structured Gd2O3:Eu(3+) phosphor prepared by spray pyrolysis: the effect of preparation conditions on microstructure and luminescence properties.

    Science.gov (United States)

    Cho, Jung Sang; Jung, Kyeong Youl; Kang, Yun Chan

    2015-01-14

    Gd2O3:Eu(3+) yolk-shell phosphor powders with high photoluminescence intensity were prepared by spray pyrolysis. Preparation temperature and spray solution concentration were varied to find the optimum process conditions for preparation of Gd2O3:Eu(3+) with yolk-shell structure. The formation mechanism of yolk-shell Gd2O3:Eu(3+) was systematically investigated by observing the microstructures of particles produced under various preparation conditions. The morphological structure of Gd2O3:Eu(3+) powders was clearly dependent on reactor temperature and on the precursor solution concentration. Eventually, pure yolk-shell structured Gd2O3:Eu(3+) powders were obtained for a reaction temperature of 1000 °C and concentration of the spray solution below 0.2 M. Also, the yolk-shell structure formed showed high thermal stability, making it possible to maintain the original spherical yolk-shell structure through calcination at high temperatures. As a result, highly crystalline Gd2O3:Eu(3+) phosphor powders having yolk-shell structure and an agglomeration-free spherical shape were successfully synthesized by spray pyrolysis. These phosphor powders were shown to have good photoluminescence characteristics. PMID:25424414

  1. Chemical and physical characterisation of biomass-based pyrolysis oils. Literature view

    Energy Technology Data Exchange (ETDEWEB)

    Fagernaes, L. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1995-12-31

    Biomass-based pyrolysis oils are complex mixtures of mainly organic compounds and water. The determination of their physical and chemical properties and chemical composition is a challenge for researchers. Characterisation of biomass pyrolysis oils has been studied at many universities in North America and Europe in the 1980s and 1990s. The existing literature on the analytical methods used for these oils is reviewed in this report. For characterising the chemical composition, the bio-oils have first been mainly fractionated into different classes. Solvent extraction and adsorption chromatography are the most general methods used. In adsorption chromatography, the oils have been fractionated into different hydrocarbon and polar fractions. The fractions obtained have been analysed with various chromatographic and spectroscopic methods. Gas chromatography/mass spectrometry (GC/MS) technique is the analytical method most widely used and well adaptable for the fractions. For high-molecular-mass and highly polar compounds liquid chromatographic (LC) techniques as well as infrared (FT-IR) and nuclear magnetic resonance (1H NMR and 13C NMR) spectroscopies are more suitable due to the low volatility of pyrolysis oils. For whole pyrolysis oils, LC techniques, primarily size exclusion chromatography and FT-IR and FT-NMR spectroscopies have proved to be useful methods

  2. Synthesis of nanocrystalline Cu{sub 2}ZnSnS{sub 4} thin films grown by the spray-pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Chandel, Tarun, E-mail: tarunchandel777@yahoo.com; Singh, Joginder; Rajaram, P. [School of Studies in Physics, Jiwaji University, Gwalior (MP), India-474011 (India)

    2015-08-28

    Spray pyrolysis was used to deposit Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films on soda lime glass substrates at 300 °C. Aqueous solutions of copper chloride, zinc chloride, stannous chloride and thiourea were mixed together to form the spray liquid. The sprayed films were annealed under vacuum at 350 °C, 400 °C and 450 °C. Structural and optical characterization was performed on the CZTS films using X-ray diffraction (XRD) and UV-VIS spectrophotometry. XRD results indicate that the films are single phase nanocrystalline CZTS. Optical studies show that the optical gap values are 1.44 eV for the as-grown film and 1.46 eV, 1.48 eV and 1.49 eV for the films annealed at 350 °C, 400 °C and 450 °C, respectively.

  3. Y2SiO5:Tb phosphor particles prepared from colloidal and aqueous solutions by spray pyrolysis

    International Nuclear Information System (INIS)

    Green-emitting Y2SiO5:Tb phosphor particles with fine size, spherical shape, filled morphology, high crystallinity, and good brightness were synthesized by a spray pyrolysis process. The effect of silicon precursor type on the morphology, crystal structure, crystallinity, and photoluminescence efficiency of Y2SiO5:Tb phosphor particles was investigated. The particles prepared from an artificial colloidal solution obtained by dispersing fumed silica particles had a pure monoclinic X2 crystalline phase, which is more appropriate for application to displays, after post-treatment at 1300 C. On the other hand, the particles prepared from 100% tetraethyl orthosilicate (TEOS) reagent had an X2 phase and small amounts of X1 and impurity phases such as Y2Si2O7 and Y4.67Si3O13 due to the phase-segregation characteristics of the TEOS precursor. The photoluminescence characteristics of Y2SiO5:Tb phosphor particles were strongly affected by the silicon source used. The photoluminescence intensities increased with the fumed silica/TEOS ratio. The particles prepared from 100% fumed silica showed the maximum photoluminescence intensity, which is 22% higher than that of particles prepared from 100% TEOS. (orig.)

  4. Synthesis of nano structured particles for Li-ion cathodic and anodic materials obtained by spray pyrolysis

    International Nuclear Information System (INIS)

    The development of the nano technology has contributed to improve the electrochemical properties in rechargeable batteries. The Spray Pyrolysis method allows to obtain nano structured materials with spherical morphology, narrow particle size distribution and compositional homogeneity. Nano structured particles have been prepared in this work to be used as anodic and cathodic materials in lithium-ion batteries. Among the cathodic materials, the Na-Si-Con (Li3Fe2(PO4)3) structure and the olivine (LiFePO4) phases have been synthesised. The Na-Si-Con iron phosphate favours the accommodation of the ion host, the diffusion and thermal stability. The olivine structure has an open three-dimensional network, favourable for hosting Lithium ions. The characterization by X ray diffraction, electron microscopy (scanning and transmission) and electron diffraction have allowed to identify a mix of crystalline phases of LiFePO4 (Olivine) and Li3Fe2(PO4)3 (Na-Si-Con). Thermal treatments produce porous particles. The tryphilite phase (olivine) appears after a thermal treatment at 800 degree centigrade/12h. Electrochemical results confirm the presence of the Na-Si-Con and olivine phases. Among the materials for being used as anode, the titanium oxides have been classified as good candidates as lithium ion host. The synthesis results in different experimental conditions for obtaining spherical and nano structured titanium oxide particles are presented. (Author)

  5. Influences of Pr and Ta doping concentration on the characteristic features of FTO thin film deposited by spray pyrolysis

    Institute of Scientific and Technical Information of China (English)

    G ¨uven Turgut; Adem Koc¸ yi˘git; Erdal S ¨onmez

    2015-01-01

    The Pr and Ta separately doped FTO (10 at.%F incorporated SnO2) films are fabricated via spray pyrolysis. The mi-crostructural, topographic, optical, and electrical features of fl uorine-doped TO (FTO) films are investigated as functions of Pr and Ta dopant concentrations. The x-ray diffraction (XRD) measurements reveal that all deposited films show polycrys-talline tin oxide crystal property. FTO film has (200) preferential orientation, but this orientation changes to (211) direction with Pr and Ta doping ratio increasing. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) anal-yses show that all films have uniform and homogenous nanoparticle distributions. Furthermore, morphologies of the films depend on the ratio between Pr and Ta dopants. From ultraviolet-visible (UV-Vis) spectrophotometer measurements, it is shown that the transmittance value of FTO film decreases with Pr and Ta doping elements increasing. The band gap value of FTO film increases only at 1 at.%Ta doping level, it drops off with Pr and Ta doping ratio increasing at other doped FTO films. The electrical measurements indicate that the sheet resistance value of FTO film initially decreases with Pr and Ta doping ratio decreasing and then it increases with Pr and Ta doping ratio increasing. The highest value of figure of merit is obtained for 1 at.%Ta-and Pr-doped FTO film. These results suggest that Pr-and Ta-doped FTO films may be appealing candidates for TCO applications.

  6. Optical properties and mechanisms of current flow in Cu2ZnSnS4 films prepared by spray pyrolysis

    Science.gov (United States)

    Orletskii, I. G.; Mar'yanchuk, P. D.; Solovan, M. N.; Brus, V. V.; Maistruk, E. V.; Kozyarskii, D. P.; Abashin, S. L.

    2016-05-01

    Thin films Cu2ZnSnS4 (up to 0.9 μm thick) with p-type conductivity and band gap E g = 1.54 eV have been prepared by the spray pyrolysis of 0.1 M aqueous solutions of the salts CuCl2 · 2H2O, ZnCl2 · 2H2O, SnCl4 · 5H2O, and (NH2)2CS at a temperature T S = 290°C. The electrophysical properties of the films have been analyzed using the model for polycrystalline materials with electrically active grain boundaries. The energy and geometric parameters of the grain boundaries have been determined as follows: the height of the barriers is E b ≈ 0.045-0.048 eV, and the thickness of the depletion region is δ ≈ 3.25 nm. The effective concentrations of charge carriers p 0 = 3.16 × 1018 cm-3 and their mobilities in crystallites μ p = 85 cm2/(V s) have been found using the technique for determining the kinetic parameters from the absorption spectra of thin films at a photon energy hν ≈ E g . The density of states at grain boundaries N t = 9.57 × 1011 cm-2 has been estimated.

  7. Influence of concentration and volume of precursor on the electrochemical properties of vanadium oxide thin films prepared by spray pyrolysis

    Science.gov (United States)

    Ingole, R. S.; Fugare, B. Y.; Lokhande, B. J.

    2016-04-01

    Vanadium oxide (V2O5) thin films have been prepared by spray pyrolysis using different concentrations and volumes of precursor solution via aqueous route at 673K deposition temperature. The influences of concentration and volume on the structural, morphological and electrochemical properties of the deposited samples are studied well. X - ray diffraction study shows orthorhombic crystal structure with V2O5 phase, confirmed by FTIR spectroscopy. Scanning electron microscopy shows granular, homogeneous and dense surface morphology. Cyclic voltammetery of all samples carried at all scan rates. Samples prepared using 0.05M, 40 ml of precursor solution shows highest specific capacitance 428.25 F/gm at 5 mV/s, Charge discharge behavior exhibits specific energy 18.73 Wh/kg, specific power 36.00 kW/kg, columbic efficiency 87.50 %. Impedance spectroscopy study was carried in the frequency range 1mHz - 1MHz, reveals pseudocapacitive behavior of the electrode exhibiting internal resistance 1.34 ohm.

  8. One-Step Synthesis of TiO2/Perlite Composites by Flame Spray Pyrolysis and Their Photocatalytic Behavior

    Directory of Open Access Journals (Sweden)

    M. Giannouri

    2013-01-01

    Full Text Available TiO2/perlite composites were prepared via facile one-step flame spray pyrolysis (FSP route. Titanium alkoxide (TIPO and expanded perlite were used as Ti source and substrate, respectively. Precursor TIPO-ethanol solutions containing homogeneously dispersed perlite particles were processed through FSP setup at different experimental conditions regarding the gas flow and precursor supply rates. The structure, morphology, and the composition of the obtained powders were investigated. The porosity and the light absorbance of the TiO2/perlite composites were examined and their photocatalytic activity in NO oxidation was evaluated. Commercial titania powder P25 was also FSP processed and investigated for comparison. The XRD analysis revealed that biphased titania with different anatase-rutile ratio and particles size 20–40 nm was synthesized onto the perlite which according to microscopy results was covered by neck-connected TiO2 nanoparticles. The anatase-rutile interplay was also demonstrated by the Raman spectra where presence of Si-O-Ti vibrational modes was observed for some samples. The UV-Vis diffuse reflectance spectra of the TiO2/perlite composites revealed up to 70% reflection that was connected to the presence of the gray perlite and superficial carbon. The best photocatalytic activity of the composites was connected to almost equal anatase-rutile ratio and possible synergetic effect of the two TiO2 phases.

  9. Probing the doping mechanisms and electrical properties of Al, Ga and In doped ZnO prepared by spray pyrolysis

    KAUST Repository

    Maller, Robert

    2016-05-24

    The measured structural, optical and electrical properties of Al, Ga and In doped ZnO films deposited using spray pyrolysis are reported over the doping range 0.1 - 3 atomic percent (at. %). Over the entire doping series highly transparent, polycrystalline thin films are prepared. Using the AC Hall effect we probe the electronic properties of our doped films separating the impact of doping on the measured charge carrier concentrations and Hall mobility, with an emphasis on the low doping, < 1 at. %, range. In this doping range highly resistive films are formed and we highlight AC Hall as a reliable and highly reproducible technique for analysing the doping mechanism. The implementation of a simple, post-deposition heat treatment of our AZO films creates typical films with charge carrier concentrations exceeding > 1019 cm-3 and electron mobilities over 10 cm2/Vs. We describe in detail the nature of the defect chemistry and the role of intrinsic defects, particularly traps, and show that despite significant variations in dopant species and grain boundary concentrations that the defect chemistry dominates the electrical characteristics.

  10. Spray pyrolysis prepared yellow to red color tunable Sr₁-xCaxSe:Eu²+ phosphors for white LED.

    Science.gov (United States)

    Chung, Wonkeun; Jung, Hyunchul; Lee, Chang Hun; Kim, Jihyun; Kim, Sung Hyun

    2012-06-01

    The spherical and submicron size of Sr₁-xCaxSe:Eu²⁺ phosphors were successfully prepared by ultrasonic spray pyrolysis. The phosphors adopted a cubic structure, and the replacement of Sr²⁺ with Ca²⁺ decreased the lattice parameter. The Sr₁-xCaxSe:Eu²⁺ showed broad and strong excitation under 420-460 nm blue light, and the emission band could be tuned from 565 to 607 nm by increasing the Ca²⁺ ratio in the host lattice. In addition, the doping of Zn²⁺ into Sr²⁺ or Ca²⁺ enhanced the emission intensity with a small red shift due to the change in crystal field strength and nephelauxetic effects. The warm and high CRI of white LED was achieved using blue LED pumped with blending phosphors of 612 nm emitting Ca₀.₉₈Zn₀.₀₂Se:Eu²⁺ and 565 nm emitting YAG. The correlated color temperatures and CRI were 4719.2K, and 86.3, respectively, and an acceptable color variation was also observed at operating currents ranging from 20 to 70 mA. PMID:22714315

  11. Optical and electrical characterization of AgInS{sub 2} thin films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Calixto-Rodriguez, M., E-mail: manuela@fis.unam.mx [Instituto de Ciencias Fisicas-Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62210, Cuernavaca, Morelos (Mexico); Martinez, H. [Instituto de Ciencias Fisicas-Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62210, Cuernavaca, Morelos (Mexico); Calixto, M.E. [Instituto de Fisica, Benemerita Universidad Autonoma de Puebla, Apartado Postal J-48, 72570, Puebla, Puebla (Mexico); Pena, Y. [Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, Pedro de Alba s/n, Ciudad Universitaria, 66451, San Nicolas de los Garza, Nuevo Leon (Mexico); Martinez-Escobar, Dalia [Centro de Investigacion en Energia-Universidad Nacional Autonoma de Mexico, 62580, Temixco, Morelos (Mexico); Tiburcio-Silver, A. [Instituto Tecnologico de Toluca-SEP, Apartado Postal 20, 52176, Metepec 3, Estado de Mexico (Mexico); Sanchez-Juarez, A. [Centro de Investigacion en Energia-Universidad Nacional Autonoma de Mexico, 62580, Temixco, Morelos (Mexico)

    2010-10-25

    Silver indium sulfide (AgInS{sub 2}) thin films have been prepared by spray pyrolysis (SP) technique using silver acetate, indium acetate, and N, N-dimethylthiourea as precursor compounds. Films were deposited onto glass substrates at different substrate temperatures (T{sub s}) and Ag:In:S ratios in the starting solutions. Optical transmission and reflection as well as electrical measurements were performed in order to study the effect of deposition parameters on the optical and electrical properties of AgInS{sub 2} thin films. X-ray diffraction measurements were used to identify the deposited compounds. It was found that different compounds such as AgInS{sub 2}, Ag{sub 2}S, In{sub 2}O{sub 3}, and In{sub 2}S{sub 3} can be grown only by changing the Ag:In:S ratio in the starting solution and T{sub s}. So that, by carefully selecting the deposition parameters, single phase AgInS{sub 2} thin films can be easily grown. Thin films obtained using a molar ratio of Ag:In:S = 1:1:2 and T{sub s} = 400 {sup o}C, have an optical band gap of 1.9 eV and n-type electrical conductivity with a value of 0.3 {Omega}{sup -1} cm{sup -1} in the dark.

  12. Electrochromic characteristics of fibrous reticulated WO{sub 3} thin films prepared by pulsed spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Bathe, Suvarna R.; Patil, P.S. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004 (India)

    2007-07-23

    The electrochromic (EC) behavior of fibrous reticulated WO{sub 3} films prepared from ammonium tungstate precursor by pulsed spray pyrolysis method was investigated. All the films were prepared using identical technological parameters and a thorough investigation of the electrochromic properties of the films deposited at 300 C is reported. The structural properties were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochromic and optical properties were measured using cyclic voltammetry and ultraviolet (UV)-visible spectrophotometry. The films are amorphous and have a fibrous reticulate-like morphology having micron-size circular rings. The films show high transparency in the visible range and the optical band gap energy is about 3.1 eV. Electrical measurements show that the resistivity monotonically decreases as temperature increases, which indicates thermal hopping transport. The activation energy for hopping transport is of the order 4 x 10{sup -4} eV. The electrochromic coloration efficiency (CE) is found to be 34 cm{sup 2}/C at 630 nm. (author)

  13. Influence of solvent on the structural and morphological properties of AgI particles prepared using ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Silver iodide particles were synthesized in the process of ultrasonic spray pyrolysis using aqueous solutions of thermodynamically stable silver iodide clusters as precursor. The AgI particles were collected in solvents of different polarities such as water, 2-propanol and toluene. In order to study influence of solvent and aging time on the morphological and structural properties of the AgI particles ultra-filtration was employed to isolate solid material from solution. The scanning electron microscopy showed that morphology of the AgI particles is different for different solvents. The AgI particles with hexagonal/triangular shape were obtained in water and toluene, while in 2-propanol hollow spheres were formed. The X-ray diffraction analysis, besides wurtzite hexagonal and zinc blende cubic phases, revealed appearance of tetragonal high-pressure AgI modification for sample collected in toluene and for sample aged in 2-propanol. The aging in toluene induced transformation of all three modifications into single phase with one preferred orientation

  14. Structural, optical and photoluminescence study of nanocrystalline SnO2 thin films deposited by spray pyrolysis

    Indian Academy of Sciences (India)

    Akhilesh Tripathi; R K Shukla

    2014-05-01

    Undoped SnO2 thin films prepared by spray pyrolysis method reveal polycrystalline nature with prominent peaks along (110), (101) and (211) planes. All the films are nanocrystalline with particle size lying in the range of 3.14–8.6 nm calculated by DS formula. Orientation along plane (200) decreases continuously as molar concentration of SnO2 increases. Dislocation density along plane (110) also decreases as molar concentration increases except 0.4 M SnO2 thin film. Scanning electron microscopy image of the films contain jelly structures along with agglomerated clusters of particles. SnO2 synthesized successfully, which confirms by Fourier transform infra-red spectroscopy. The optical transmittance spectra of 0.2 M SnO2 thin film shows transmittance about 50–60% transmission in visible and near infrared region with a sharp cut off in the ultraviolet region. The transmission decreases in visible and near infrared region as molar concentration increases. Broad UV emission at 398 nm is observed in photoluminescence spectra of the films along with a blue emission, when excited at 250 nm wavelength. Emission intensity randomly changed as SnO2 molar concentration increases. When excited at 320 nm, one UV and two visible peaks appeared at 385, 460 and 485 nm, respectively.

  15. Synthesis, characterization and gas sensing performance of SnO2 thin films prepared by spray pyrolysis

    Indian Academy of Sciences (India)

    Ganesh E Patil; D D Kajale; D N Chavan; N K Pawar; P T Ahire; S D Shinde; V B Gaikwad; G H Jain

    2011-02-01

    In this work, SnO2 thin films were deposited onto alumina substrates at 350°C by spray pyrolysis technique. The films were studied after annealing in air at temperatures 550°C, 750°C and 950°C for 30 min. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical absorption spectroscopy technique. The grain size was observed to increase with the increase in annealing temperature. Absorbance spectra were taken to examine the optical properties and bandgap energy was observed to decrease with the increase in annealing temperature. These films were tested in various gases at different operating temperatures ranging from 50–450°C. The film showed maximum sensitivity to H2S gas. The H2S sensing properties of the SnO2 films were investigated with different annealing temperatures and H2S gas concentrations. It was found that the annealing temperature significantly affects the sensitivity of the SnO2 to the H2S. The sensitivity was found to be maximum for the film annealed at temperature 950°C at an operating temperature of 100°C. The quick response and fast recovery are the main features of this film. The effect of annealing temperature on the optical, structural, morphological and gas sensing properties of the films were studied and discussed.

  16. Comparative studies of spray pyrolysis deposited copper sulfide nanostructural thin films on glass and FTO coated glass

    Indian Academy of Sciences (India)

    Mehdi Adelifard; Hosein Eshghi; Mohamad Mehdi Bagheri Mohagheghi

    2012-10-01

    CuS thin films with different Cu to S molar ratios (0.33 and 0.43) have been deposited by spray pyrolysis method on glass and FTO coated glass substrates using an aqueous solution of copper (II) acetate and thiourea at a substrate temperature of 285°C. The structural, surface morphological, optical and electrical characterizations of the samples were carried out using XRD, FESEM, UV-Vis and PL spectrophotometer and four-probe apparatus, respectively. X-ray diffraction analysis showed that while the layer/glass sample has an individual CuS (covellite) crystalline phase, the layer/FTO sample includes two additional phases of Cu2S (chalcocite) and Cu1.8S (digenite) as well. Optical measurements showed that all these materials have a relatively high absorption coefficient (∼5 × 104–2.3 × 105 cm-1) in the visible region and direct bandgap of the layers was confirmed with the corresponding room temperature PL spectra. With the resistivity measurements at room and higher temperatures (up to 100°C) confirm that all samples are degenerate in nature with high electrical conductivities of ∼103 (.cm)-1.

  17. 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.)

  18. Double-layer indium doped zinc oxide for silicon thin-film solar cell prepared by ultrasonic spray pyrolysis

    Institute of Scientific and Technical Information of China (English)

    Jiao Bao-Chen; Zhang Xiao-Dan; Wei Chang-Chun; Sun Jian; Ni Jian; Zhao Ying

    2011-01-01

    Indium doped zinc oxide (ZnO:In) thin films were prepared by ultrasonic spray pyrolysis on corning eagle 2000 glass substrate. 1 and 2 at.% indium doped single-layer ZnO:In thin films with different amounts of acetic acid added in the initial solution were fabricated. The 1 at.% indium doped single-layers have triangle grains. The 2 at.% indium doped single-layer with 0.18 acetic acid adding has the resistivity of 6.82 × 10-3 Ω· cm and particle grains. The double-layers structure is designed to fabricate the ZnO:In thin film with low resistivity (2.58×10-3 Ω· cm) and good surface morphology. It is found that the surface morphology of the double-layer ZnO:In film strongly depends on the substrate-layer, and the second-layer plays a large part in the resistivity of the double-layer ZnO:In thin film. Both total and direct transmittances of the double-layer ZnO:In film are above 80% in the visible light region. Single junction a-Si:H solar cell based on the double-layer ZnO:In as front electrode is also investigated.

  19. Transparent and conductive Al/F and In co-doped ZnO thin films deposited by spray pyrolysis

    Science.gov (United States)

    Hadri, A.; Taibi, M.; El hat, A.; Mzerd, A.

    2016-02-01

    In doped ZnO (IZO), In-Al co-doped ZnO (IAZO) and In-F co-doped ZnO (IFZO) were deposited on glass substrates at 350 °C by spray pyrolysis technique. The structural, optical and electrical properties of as-deposited thin films were investigated and compared. A polycrystalline and (002) oriented wurtzite crystal structure was confirmed by X-ray patterns for all films; and the full width at half -maximum (FWHM) of (002) diffraction peak increased after co-doping. The investigation of the optical properties was performed using Uv-vis spectroscopy. The average transmittances of all the films were between 70 and 85%. Hall Effect measurements showed that the electrical conductivity of co-doped films increased as compared with IZO thin film. The highest conductivity of about 16.39 Ω-1 cm-1 was obtained for as-deposited IFZO thin film. In addition, the thin films were annealed at 350 °C for two hour under Ar atmosphere and their optical, electrical properties and the associated photoluminescence (PL) responses of selected films were analysed. After annealing, the electrical conductivity of all thin films was improved and the optical transmittance remained above 70%. Room temperature PL revealed that the annealed IAZO thin film had a strong green emission than that of IZO film.

  20. Ni-SiO2 Catalysts for the Carbon Dioxide Reforming of Methane: Varying Support Properties by Flame Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Emma C. Lovell

    2015-03-01

    Full Text Available Silica particles were prepared by flame spray pyrolysis (FSP as a support for nickel catalysts. The impact of precursor feed rate (3, 5 and 7 mL/min during FSP on the silica characteristics and the ensuing effect on catalytic performance for the carbon dioxide, or dry, reforming of methane (DRM was probed. Increasing the precursor feed rate: (i progressively lowered the silica surface area from ≈340 m2/g to ≈240 m2/g; (ii altered the silanol groups on the silica surface; and (iii introduced residual carbon-based surface species to the sample at the highest feed rate. The variations in silica properties altered the (5 wt % nickel deposit characteristics which in turn impacted on the DRM reaction. As the silica surface area increased, the nickel dispersion increased which improved catalyst performance. The residual carbon-based species also appeared to improve nickel dispersion, and in turn catalyst activity, although not to the same extent as the change in silica surface area. The findings illustrate both the importance of silica support characteristics on the catalytic performance of nickel for the DRM reaction and the capacity for using FSP to control these characteristics.

  1. Correlation between porous structure and electrochemical properties of porous nanostructured vanadium pentoxide synthesized by novel spray pyrolysis

    Science.gov (United States)

    Kong, Long; Taniguchi, Izumi

    2016-04-01

    Porous nanostructured vanadium pentoxide (V2O5) particles were successfully prepared by spray pyrolysis (SP) in a precursor solution with an ammonium nitrate (NH4NO3) additive. The correlation between the porous structure and the electrochemical properties of the V2O5 particles was investigated. The porous structure markedly changed upon increasing the concentration of NH4NO3 in the precursor solution from 0 to 0.408 mol L-1. Pore structure analysis based on N2 adsorption-desorption isotherm measurements indicated that porous nanostructured V2O5 particles with a pore size of less than 100 nm can be prepared by the novel SP method and that an increase in the NH4NO3 concentration in the precursor solution can enlarge the pores in the V2O5 particles, especially those with a size between 20 and 80 nm. The porous nanostructured V2O5 prepared with an NH4NO3 concentration of 0.272 mol L-1 exhibited a first discharge capacity of 400 mAh g-1 at 20 mA g-1. The unique porous structure of V2O5 particles significantly enhanced the rate performance and exhibited a first discharge capacity of 180 mAh g-1 at 1200 mA g-1, which is much higher than that of dense V2O5 particles (70 mAh g-1).

  2. Ni-SiO₂ catalysts for the carbon dioxide reforming of methane: varying support properties by flame spray pyrolysis.

    Science.gov (United States)

    Lovell, Emma C; Scott, Jason; Amal, Rose

    2015-01-01

    Silica particles were prepared by flame spray pyrolysis (FSP) as a support for nickel catalysts. The impact of precursor feed rate (3, 5 and 7 mL/min) during FSP on the silica characteristics and the ensuing effect on catalytic performance for the carbon dioxide, or dry, reforming of methane (DRM) was probed. Increasing the precursor feed rate: (i) progressively lowered the silica surface area from ≈340 m2/g to ≈240 m2/g; (ii) altered the silanol groups on the silica surface; and (iii) introduced residual carbon-based surface species to the sample at the highest feed rate. The variations in silica properties altered the (5 wt %) nickel deposit characteristics which in turn impacted on the DRM reaction. As the silica surface area increased, the nickel dispersion increased which improved catalyst performance. The residual carbon-based species also appeared to improve nickel dispersion, and in turn catalyst activity, although not to the same extent as the change in silica surface area. The findings illustrate both the importance of silica support characteristics on the catalytic performance of nickel for the DRM reaction and the capacity for using FSP to control these characteristics. PMID:25774491

  3. Preparation of Spherical Zn-Substituted Tricalcium Phosphate Powder by Ultrasonic Spray-Pyrolysis Technique and Its Characterization

    Directory of Open Access Journals (Sweden)

    Hiroki Nishikawa

    2016-01-01

    Full Text Available Zinc, an essential trace element, has a stimulatory effect on bone formation. To enhance the osteoconduction of implant materials such as hydroxyapatite and tricalcium phosphate (TCP, zinc was incorporated into them. In this study, we have synthesized spherical zinc-substituted TCP (Zn-TCP powders using ultrasonic spray-pyrolysis technique, fabricated Zn-TCP ceramics, and characterized their powder properties. Four kinds of Zn-TCPs with various amounts of zinc content were prepared, to examine the influence of zinc addition to the crystal structure of TCP and to compare the different Zn-TCPs with each other. Zn-TCP ceramics were fabricated from the resulting powders under different sintering temperatures. Zn-TCP samples were analyzed and led to the following results: the resulting powders were composed of α- and β-TCP phases, whereas the fabricated ceramics mainly consisted of β-TCP phase. The determination of zinc content in the resulting powders and fabricated ceramics showed a maximum content of ~12 mol%. The resulting powders consisted of spherical particles with diameters <2 μm. The lattice constants of ceramics did not show a significant change of the a-axis, b-axis, and c-axis. The bulk density of Zn-TCPs showed their maximum at 1100°C, while the bulk density of Zn-TCP(0 was greatest at 1000°C.

  4. Luminescence properties of Eu-complex formations into ordered mesoporous silica particles obtained by the spray pyrolysis process.

    Science.gov (United States)

    Rocha, Lucas A; Freiria, Janaina do C; Caiut, José Maurício A; Ribeiro, Sidney J L; Messaddeq, Younes; Verelst, Marc; Dexpert-Ghys, Jeannette

    2015-08-21

    Ordered mesoporous, highly luminescent SiO2 particles have been synthesized by spray pyrolysis from solutions containing tetraethylorthosilicate (TEOS), Eu(NO3)3.6H2O, and cetyltrimethylammonium bromide (CTAB) as structure-directing agents. The 1,10-phenantroline (Phen) molecules were coordinated in a post-synthesis step by a simple wet impregnation method. In addition, other matrices were also prepared by the encapsulation of europium complex Eu(fod)3 (where fod = 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato) into mesoporous silica, and then the Phen molecules were encapsulated by different impregnation steps, after which the luminescence properties were investigated. The obtained materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder x-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Powders with polydisperse spherical grains were obtained, displaying an ordered hexagonal array of mesochannels. Luminescence results revealed that Phen molecules had been successfully coordinated as an additional ligand in the Eu(fod)3 complex into the channels of the mesoporous particles without disrupting the structure. PMID:26222799

  5. Growth of tin oxide thin films composed of nanoparticles on hydrophilic and hydrophobic glass substrates by spray pyrolysis technique

    Science.gov (United States)

    Paloly, Abdul Rasheed; Satheesh, M.; Martínez-Tomás, M. Carmen; Muñoz-Sanjosé, Vicente; Rajappan Achary, Sreekumar; Bushiri, M. Junaid

    2015-12-01

    In this paper, we have demonstrated the growth of tin oxide (SnO2) thin films composed of nanoparticles on hydrophobic (siliconized) and hydrophilic (non-siliconized) glass substrates by using the spray pyrolysis technique. X-ray diffraction (XRD) analysis confirmed the formation of SnO2 thin films with tetragonal rutile-phase structure. Average particle size of nanoparticles was determined to be in the range of 3-4 nm measured from the front view images obtained by a field emission gun scanning electron microscope (FESEM), while the size of nanoparticle clusters, when present, were in the range of 11-20 nm. Surface morphology of SnO2 films grown over hydrophobic substrates revealed larger isolated particles which are less crowded compared to the highly crowded and agglomerated smaller particles in films on hydrophilic substrates. Blue shift in the band gap is observed in samples in which the average particle size is slightly larger than the exciton Bohr radius. Photoluminescence (PL) analysis of samples grown over hydrophobic substrates exhibited an intense defect level emission and a weak near band edge emission. The enhanced visible emission from these SnO2 thin films is attributed to lattice defects formed during the film growth due to the mismatch between the film and the hydrophobic substrate surface.

  6. Novel morphology of needle-Like nanoparticles of Na2Mo2O7 synthesized by using Ultrasonic spray pyrolysis

    Directory of Open Access Journals (Sweden)

    Ivana Lj. Validžić

    2013-02-01

    Full Text Available Low-temperature method for the synthesis of novel morphology of needle-like nanoparticles of disodium dimolybdate (Na2Mo2O7 in the process of ultrasonic spray pyrolysis (USP using aqueous solutions of thermodynamically stable molybdenum (VI oxide clusters as precursor is described. Needle-like Na2Mo2O7 particles were obtained and collected in toluene, while centrifugation was employed to isolate solid material from solution. The scanning electron microscopy (SEM confirmed that the morphology of the synthesized Na2Mo2O7 particles is needle-like collected into bundles. The X-ray Powder Diffraction (XRPD analysis revealed appearance of orthorhombic Na2Mo2O7, synthesized at 300 °C. By comparing the XRPD pattern of the synthesized needle-like Na2Mo2O7 powder obtained in the process of USP with the XRPD pattern simulated for randomly-distributed crystallites by planes, the most prefered growth plane of needle-like nanoparticles were found.

  7. Novel Morphology of Needle-Like Nanoparticles of Na2Mo2O7 Synthesized by Using Ultrasonic Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Ivana Lj. Validžić

    2012-01-01

    Full Text Available Low-temperature method for the synthesis of novel morphology of needle-like nanoparticles of disodium dimolybdate (Na2Mo2O7 in the process of ultrasonic spray pyrolysis (USP using aqueous solutions of thermodynamically stable molybdenum (VI oxide clusters as precursor is described. Needle-like Na2Mo2O7 particles were obtained and collected in toluene, while centrifugation was employed to isolate solid material from solution. The scanning electron microscopy (SEM confirmed that the morphology of the synthesized Na2Mo2O7 particles is needle-like collected into bundles. The X-ray Powder Diffraction (XRPD analysis revealed appearance of orthorhombic Na2Mo2O7, synthesized at 300 °C. By comparing the XRPD pattern of the synthesized needle-like Na2Mo2O7 powder obtained in the process of USP with the XRPD pattern simulated for randomly-distributed crystallites by planes, the most prefered growth plane of needle-like nanoparticles were found.

  8. Structural and Photoelectrochemical Properties of Cu-Doped CdS Thin Films Prepared by Ultrasonic Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Rui Xie

    2013-01-01

    Full Text Available Cu-doped CdS thin films of variable doping levels have been deposited on indium tin oxide-coated glass substrate by simple and cost-effective ultrasonic spray pyrolysis. The influences of doping concentration and annealing treatment on the structure and photoelectrochemical properties of the films were investigated. The deposited films were characterized by XRD, SEM, and UV-Vis spectra. Moreover, the films were investigated by electrochemical and photoelectrochemical measurements with regard to splitting water for solar energy conversion. The results showed that the Cu impurity can cause a structural change and red shift of absorption edge. It was found that the photocurrent can be improved by the Cu-doping process for the unannealed films under the weak illumination. The unannealed 5 at.% Cu-doped sample obtained the maximum IPCE, which achieved about 45% at 0.3 V versus SCE potential under 420 nm wavelength photoirradiation. In addition, the p-type CdS was formed with a doping of 4 at.%~10 at.% Cu after 450°C 2 h annealed in vacuum.

  9. Nano porous Al2O3-TiO2 thin film based humidity sensor prepared by spray pyrolysis technique

    Science.gov (United States)

    Chandrashekara, H. D.; Angadi, Basavaraj; Ravikiran, Y. T.; Poornima, P.; Shashidhar, R.; Murthy, L. C. S.

    2016-05-01

    The nano porous surface structured TiO2 and Al2O3-TiO2 thin films were prepared using spray pyrolysis technique at 350°C. The XRD pattern of Al2O3-TiO2 film shows anatase phase and mixed phase of Al2TiO5. The surface morphology of films show a uniformly distributed nano porous structure. The elemental analysis through EDAX shows good stoichiometry. The sensitivity for humidity sensing were determined for both films of TiO2 and Al2O3-TiO2 and corresponding values are found to be 74.2% and 84.02%, this result reveal that Al2O3-TiO2 films shows higher sensing percent than the TiO2 due to the nano porous surface nature. The Al2O3-TiO2 film shows fast response time and long recovery time than the TiO2 film, this may be due to the meso-porous morphology of these films.

  10. Highly photoconducting O2-doped CdS films deposited by spray pyrolysis

    Science.gov (United States)

    Richards, D.; El-Korashy, A. M.; Stirn, R. J.; Karulkar, P. C.

    1984-01-01

    CdS films have been prepared by spraying in air solutions of thiourea with either cadmium chloride or cadmium acetate with varying mole ratio and substrate temperature, and subsequently heat treating in oxygen. Substrates included both bare glass or sapphire and transparent conducting oxide-coated sapphire for electrical measurements lateral and transverse to the CdS plane, respectively. Dark resistances of over 10 to the 14th ohms and light-to-dark conductivities of up to 10 to the 7th were obtained using uncoated substrates. The use of Cd(C2H3O2)2 in place of CdCl2 greatly increased the speed of response although with some sacrifice in photoconductivity. Deposition of CdS on ITO-coated surfaces led to greatly reduced dark resistances for the case of CdCl2, but not Cd(C2H3O2)2, presumably due to HCl reaction with the ITO coating in the course of spraying with the former. Ion microprobe analysis detected indium within the CdS films exhibiting low dark resistance. Measurements of the dark and light conductivities at temperatures down to 77 K are given as are the response times for unetched and HCl-etched surfaces.

  11. Estimation of risks by chemicals produced during laser pyrolysis of tissues

    Science.gov (United States)

    Weber, Lothar W.; Spleiss, Martin

    1995-01-01

    Use of laser systems in minimal invasive surgery results in formation of laser aerosol with volatile organic compounds of possible health risk. By use of currently identified chemical substances an overview on possibly associated risks to human health is given. The class of the different identified alkylnitriles seem to be a laser specific toxicological problem. Other groups of chemicals belong to the Maillard reaction type, the fatty acid pyrolysis type, or even the thermally activated chemolysis. In relation to the available different threshold limit values the possible exposure ranges of identified substances are discussed. A rough estimation results in an exposure range of less than 1/100 for almost all substances with given human threshold limit values without regard of possible interactions. For most identified alkylnitriles, alkenes, and heterocycles no threshold limit values are given for lack of, until now, practical purposes. Pyrolysis of anaesthetized organs with isoflurane gave no hints for additional pyrolysis products by fragment interactions with resulting VOCs. Measurements of pyrolysis gases resulted in detection of small amounts of NO additionally with NO2 formation at plasma status.

  12. Economics evaluation for on-site pyrolysis of kraft lignin to value-added chemicals.

    Science.gov (United States)

    Farag, Sherif; Chaouki, Jamal

    2015-01-01

    This work is part of a series of investigations on pyrolysis of lignin. After obtaining the necessary information regarding the quantity and quality of the obtained products, a first step economics evaluation for converting lignin into chemicals was essential. To accomplish this aim, a pyrolysis plant with a 50t/d capacity was designed, and the total capital investment and operating costs were estimated. Next, the minimal selling price of the obtained dry oil was calculated and the effect of crucial variables on the estimated price was examined. The key result indicates the estimated selling price would not compete with the price of the chemicals that are fossil fuel based, which is primarily due to the high cost of the feedstock. To overcome this challenge, different scenarios for reducing the selling price of the obtained oil, which consequently is helping by taking a place among the fossil fuel based chemicals, were discussed. PMID:25459830

  13. Rates and Mechanisms of Oil Shale Pyrolysis: A Chemical Structure Approach

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, Thomas; Pugmire, Ronald

    2015-01-01

    Three pristine Utah Green River oil shale samples were obtained and used for analysis by the combined research groups at the University of Utah and Brigham Young University. Oil shale samples were first demineralized and the separated kerogen and extracted bitumen samples were then studied by a host of techniques including high resolution liquid-state carbon-13 NMR, solid-state magic angle sample spinning 13C NMR, GC/MS, FTIR, and pyrolysis. Bitumen was extracted from the shale using methanol/dichloromethane and analyzed using high resolution 13C NMR liquid state spectroscopy, showing carbon aromaticities of 7 to 11%. The three parent shales and the demineralized kerogens were each analyzed with solid-state 13C NMR spectroscopy. Carbon aromaticity of the kerogen was 23-24%, with 10-12 aromatic carbons per cluster. Crushed samples of Green River oil shale and its kerogen extract were pyrolyzed at heating rates from 1 to 10 K/min at pressures of 1 and 40 bar and temperatures up to 1000°C. The transient pyrolysis data were fit with a first-order model and a Distributed Activation Energy Model (DAEM). The demineralized kerogen was pyrolyzed at 10 K/min in nitrogen at atmospheric pressure at temperatures up to 525°C, and the pyrolysis products (light gas, tar, and char) were analyzed using 13C NMR, GC/MS, and FTIR. Details of the kerogen pyrolysis have been modeled by a modified version of the chemical percolation devolatilization (CPD) model that has been widely used to model coal combustion/pyrolysis. This refined CPD model has been successful in predicting the char, tar, and gas yields of the three shale samples during pyrolysis. This set of experiments and associated modeling represents the most sophisticated and complete analysis available for a given set of oil shale samples.

  14. Spray pyrolysis deposition of Cu-ZnO and Zn-SnO2 solar cells

    Science.gov (United States)

    Khelfane, A.; Tarzalt, H.; Sebboua, B.; Zerrouki, H.; Kesri, N.

    2015-12-01

    Large-gap metal oxides, such as titanium, tin, and zinc oxides, have attracted great interest because of their remarkable potential in dye-sensitized solar cells (DSSC) and their low cost and simple preparation procedure. In this work, we investigated several Zn-SnO2 and Cu-ZnO thin films that were sprayed under different experimental conditions. We varied [Zn/[Sn] and [Cu/[Zn] ratios, calculated on atomic percent in the starting solution. We report some structural results of the films using X-ray diffraction. Optical reflection and transmission spectra investigated by an UV/VIS/NIR spectrophotometer permit the determination of optical constants. The direct band gap was deduced from the photon energy dependence of the absorption coefficient.

  15. Influence of solvents on properties of solar selective coatings obtained by spray pyrolysis

    Indian Academy of Sciences (India)

    Mihaela Dudita; Luminita Isac; Anca Duta

    2012-11-01

    Solar selective coatings for solar thermal flat-plate collectors consisting of crystalline copper oxides and amorphous nickel oxide composites were obtained by robotic spray pyrolyzed deposition. The parameters were optimized for increased spectral selectivity (): high solar absorptance and low thermal emittance. The coatings were deposited using nickel and copper acetate, dissolved in mixed solvents with various water: ethanol ratios. The coatings’ properties were characterized in terms of crystalline composition (XRD), surface morphology (AFM, contact angle) and optical properties (solar absorptance, thermal emittance and spectral selectivity). Considering the precursor solutions composition (solvent, wetting behaviour), the growth processes were modelled for two different systems: predominant hydrophilic and predominant hydrophobic. The high selectivity values ( > 30) of the optimized composite coatings were explained based on two parallel mechanisms: intrinsic absorption and multiple reflections generated when absorbers with controlled roughness are deposited.

  16. Spray pyrolysis deposition of Cu-ZnO and Zn-SnO2 solar cells

    International Nuclear Information System (INIS)

    Large-gap metal oxides, such as titanium, tin, and zinc oxides, have attracted great interest because of their remarkable potential in dye-sensitized solar cells (DSSC) and their low cost and simple preparation procedure. In this work, we investigated several Zn-SnO2 and Cu-ZnO thin films that were sprayed under different experimental conditions. We varied [Zn/[Sn] and [Cu/[Zn] ratios, calculated on atomic percent in the starting solution. We report some structural results of the films using X-ray diffraction. Optical reflection and transmission spectra investigated by an UV/VIS/NIR spectrophotometer permit the determination of optical constants. The direct band gap was deduced from the photon energy dependence of the absorption coefficient

  17. A detailed chemical kinetic model for pyrolysis of the lignin model compound chroman

    Directory of Open Access Journals (Sweden)

    James Bland

    2013-12-01

    Full Text Available The pyrolysis of woody biomass, including the lignin component, is emerging as a potential technology for the production of renewable fuels and commodity chemicals. Here we describe the construction and implementation of an elementary chemical kinetic model for pyrolysis of the lignin model compound chroman and its reaction intermediate ortho-quinone methide (o-QM. The model is developed using both experimental and theoretical data, and represents a hybrid approach to kinetic modeling that has the potential to provide molecular level insight into reaction pathways and intermediates while accurately describing reaction rates and product formation. The kinetic model developed here can replicate all known aspects of chroman pyrolysis, and provides new information on elementary reaction steps. Chroman pyrolysis is found to proceed via an initial retro-Diels–Alder reaction to form o-QM + ethene (C2H4, followed by dissociation of o-QM to the C6H6 isomers benzene and fulvene (+ CO. At temperatures of around 1000–1200 K and above fulvene rapidly isomerizes to benzene, where an activation energy of around 270 kJ mol-1 is required to reproduce experimental observations. A new G3SX level energy surface for the isomerization of fulvene to benzene supports this result. Our modeling also suggests that thermal decomposition of fulvene may be important at around 950 K and above. This study demonstrates that theoretical protocols can provide a significant contribution to the development of kinetic models for biomass pyrolysis by elucidating reaction mechanisms, intermediates, and products, and also by supplying realistic rate coefficients and thermochemical properties.

  18. Determination of cadmium in water samples by fast pyrolysis-chemical vapor generation atomic fluorescence spectrometry

    Science.gov (United States)

    Zhang, Jingya; Fang, Jinliang; Duan, Xuchuan

    2016-08-01

    A pyrolysis-vapor generation procedure to determine cadmium by atomic fluorescence spectrometry has been established. Under fast pyrolysis, cadmium ion can be reduced to volatile cadmium species by sodium formate. The presence of thiourea enhanced the efficiency of cadmium vapor generation and eliminated the interference of copper. The possible mechanism of vapor generation of cadmium was discussed. The optimization of the parameters for pyrolysis-chemical vapor generation, including pyrolysis temperature, amount of sodium formate, concentration of hydrochloric acid, and carrier argon flow rate were carried out. Under the optimized conditions, the absolute and concentration detection limits were 0.38 ng and 2.2 ng ml- 1, respectively, assuming that 0.17 ml of sample was injected. The generation efficiency of was 28-37%. The method was successfully applied to determine trace amounts of cadmium in two certified reference materials of Environmental Water (GSB07-1185-2000 and GSBZ 50009-88). The results were in good agreement with the certified reference values.

  19. Chemical and ecotoxicological properties of three bio-oils from pyrolysis of biomasses.

    Science.gov (United States)

    Campisi, Tiziana; Samorì, Chiara; Torri, Cristian; Barbera, Giuseppe; Foschini, Anna; Kiwan, Alisar; Galletti, Paola; Tagliavini, Emilio; Pasteris, Andrea

    2016-10-01

    In view of the potential use of pyrolysis-based technologies, it is crucial to understand the environmental hazards of pyrolysis-derived products, in particular bio-oils. Here, three bio-oils were produced from fast pyrolysis of pine wood and intermediate pyrolysis of corn stalk and poultry litter. They were fully characterized by chemical analysis and tested for their biodegradability and their ecotoxicity on the crustacean Daphnia magna and the green alga Raphidocelis subcapitata. These tests were chosen as required by the European REACH regulation. These three bio-oils were biodegradable, with 40-60% of biodegradation after 28 days, and had EC50 values above 100mgL(-1) for the crustacean and above 10mgL(-1) for the alga, showing low toxicity to the aquatic life. The toxic unit approach was applied to verify whether the observed toxicity could be predicted from the data available for the substances detected in the bio-oils. The predicted values largely underestimated the experimental values. PMID:27285282

  20. Mass production of chemicals from biomass-derived oil by directly atmospheric distillation coupled with co-pyrolysis

    OpenAIRE

    Xue-Song Zhang; Guang-Xi Yang; Hong Jiang; Wu-Jun Liu; Hong-Sheng Ding

    2013-01-01

    Production of renewable commodity chemicals from bio-oil derived from fast pyrolysis of biomass has received considerable interests, but hindered by the presence of innumerable components in bio-oil. In present work, we proposed and experimentally demonstrated an innovative approach combining atmospheric distillation of bio-oil with co-pyrolysis for mass production of renewable chemicals from biomass, in which no waste was produced. It was estimated that 51.86 wt.% of distillate just containi...

  1. Investigations on MgO-dielectric GaN/AlGaN/GaN MOS-HEMTs by using an ultrasonic spray pyrolysis deposition technique

    Science.gov (United States)

    Lee, Ching-Sung; Hsu, Wei-Chou; Liu, Han-Yin; Wu, Ting-Ting; Sun, Wen-Ching; Wei, Sung-Yen; Yu, Sheng-Min

    2016-05-01

    This work investigates GaN/Al0.24Ga0.76N/GaN metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs) grown on a Si substrate with MgO gate dielectric by using the non-vacuum ultrasonic spray pyrolysis deposition (USPD) technique. The oxide layer thickness is tuned to be 30 nm with the dielectric constant of 8.8. Electron spectroscopy for chemical analysis (ESCA), secondary ion mass spectrometry (SIMS), atomic force microscopy (AFM), transmission electron microscopy (TEM), C-V, low-frequency noise spectra, and pulsed I-V measurements are performed to characterize the interface and oxide quality for the MOS-gate structure. Improved device performances have been successfully achieved for the present MOS-HEMT (Schottky-gate HEMT) design, consisting of a maximum drain-source current density (I DS, max) of 681 (500) mA/mm at V GS = 4 (2) V, I DS at V GS = 0 V (I DSS0) of 329 (289) mA/mm, gate-voltage swing (GVS) of 2.2 (1.6) V, two-terminal gate-drain breakdown voltage (BV GD) of -123 (-104) V, turn-on voltage (V on) of 1.7 (0.8) V, three-terminal off-state drain-source breakdown voltage (BV DS) of 119 (96) V, and on/off current ratio (I on/I off) of 2.5 × 108 (1.2 × 103) at 300 K. Improved high-frequency and power performances are also achieved in the present MOS-HEMT design.

  2. Growth and Characterization of Co-Doped Fluorine and Antimony in Tin Oxide Thin Films Obtained by Ultrasonic Spray Pyrolysis

    Science.gov (United States)

    Gaewdang, Thitinai; Wongcharoen, Ngamnit

    Fluorine (F)-doped, antimony (Sb)-doped, fluorine and antimony co-doped tin oxide (SnO2) thin films were prepared by ultrasonic spray pyrolysis technique using SnCl2, NH4F and SbCl3 as precursors of Sn, F and Sb elements respectively. F and Sb doping concentrations carried out from 1 to 20 wt% and 1 to 4 wt% in F-doped and Sb-doped SnO2 films respectively. In F and Sb co-doped SnO2 films, the proportions of F and Sb to Sn in starting solution were 15 and 2 wt% respectively. XRD patterns showed that the preferred orientation of SnO2:F, SnO2:Sb and SnO2:F, Sb is dependent on the doping concentration. The variation of doping concentration and preferred orientation of the films was reflected in their morphology as investigated by SEM. The electrical properties of the films were performed by Hall effect measurements in van der Pauw configuration. The minimum resistivity values of SnO2:F and SnO2:Sb were found in the films doped with 15 wt% of F and 2 wt% of Sb. However, The minimum of resistivity value of F and Sb co-doped SnO2 films is not better than neither the one of F-doped nor the one of Sb-doped SnO2 films. The optical transmission of SnO2:F films was found to increase with increasing in F doping concentration. Whereas the optical transmission of SnO2:Sb was found to decrease with increasing in Sb concentration. The F and Sb co-doped SnO2 films annealed in three different conditions at 500°C show the lower transmission values than the value obtained in the as-prepared SnO2:F, Sb films.

  3. Synthesis and characterization of nanosized calcium phosphates by flame spray pyrolysis, and their effect on osteogenic differentiation of stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Ataol, Sibel; Tezcaner, Ayşen [Middle East Technical University, Department of Biomedical Engineering (Turkey); Duygulu, Ozgur [TUBITAK Marmara Research Center, Materials Institute (Turkey); Keskin, Dilek [Middle East Technical University, Department of Biomedical Engineering (Turkey); Machin, Nesrin E., E-mail: nesrinmachin@gmail.com [Kocaeli University, Department of Chemical Engineering (Turkey)

    2015-02-15

    The present study evaluates the synthesis of biocompatible osteoconductive and osteoinductive nano calcium phosphate (CaP) particles by industrially applied, aerosol-derived flame spray pyrolysis method for biomedical field. Calcium phosphate nanoparticles were produced in a range of calcium-to-phosphorus ratio, (1.20–2.19) in order to analyze the morphology and crystallinity changes, and to test the bioactivity of particles. The characterization results confirmed that nanometer-sized, spherical calcium phosphate particles were produced. The average primary particle size was determined as 23 nm by counting more than 500 particles in TEM pictures. XRD patterns, HRTEM, SAED, and SEM analyses revealed the amorphous nature of the as-prepared nano calcium phosphate particles at low Ca/P ratios. Increases in the specific surface area and crystallinity were observed with the increasing Ca/P ratio. TGA–DTA analysis showed that the thermally stable crystal phases formed after 700 °C. Cell culture studies were conducted with urine-derived stem cells that possess the characteristics of mesenchymal stem cells. Synthesized amorphous nanoparticles did not have cytotoxic effect at 5–50 μg/ml concentration range. Cells treated with the as-prepared nanoparticles had higher alkaline phosphatase (ALP) enzyme activity than control cells, indicating osteogenic differentiation of cells. A slight decrease in ALP activity of cells treated with two highest Ca:P ratios at 50 μg/ml concentration was observed at day 7. The findings suggest that calcium phosphate nanoparticles produced in this work have a potential to be used as biomaterials in biomedical applications.

  4. Dual acceptor doping and aging effect of p-ZnO:(Na, N) nanorod thin films by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Swapna, R., E-mail: swapna.ramella@yahoo.com, E-mail: santhoshmc@nitt.edu; Amiruddin, R., E-mail: swapna.ramella@yahoo.com, E-mail: santhoshmc@nitt.edu; Santhosh Kumar, M. C., E-mail: swapna.ramella@yahoo.com, E-mail: santhoshmc@nitt.edu [Advanced Materials Laboratory, Department of Physics, National Institute of Technology, Tiruchirappalli-620 015 (India)

    2014-01-28

    An attempt has been made to realize p-type ZnO by dual acceptor doping (Na-N) into ZnO thin films. Na and N doped ZnO thin films of different concentrations (0 to 8 at.%) have been grown by spray pyrolysis at 623 K. The grown films on glass substrate have been characterized by X-ray diffraction (XRD), Hall measurement, UV-Vis spectrophotometer, Photoluminescence (PL) and Energy dispersive spectroscopy (EDS) to validate the p-type conduction. The surface morphology and roughness of the ZnO:(Na, N) films are studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. Hall measurement shows that all the films exhibit p-type conductivity except for 0 at.% Na-N doped ZnO film. The obtained resistivity (5.60×10{sup −2} Ω cm) and hole concentration (3.15×10{sup 18} cm{sup −3}) for the best dual acceptor doped film is 6 at.%. It has been predicted that (Na{sub Zn}−N{sub O}) acceptor complex is responsible for the p-type conduction. The p-type conductivity of the ZnO:(Na, N) films is stable even after 6 months. The crystallinity of the films has been studied by XRD. Energy dispersive spectroscopy (EDS) confirms the presence of Na and N in 6 at.% ZnO:(Na, N) film. Photoluminescence (PL) spectra of ZnO:(Na, N) films show NBE and deep level emissions in the UV and visible regions, respectively. The ZnO:(Na, N) films exhibit a high transmittance about 90% in the visible region.

  5. Dual acceptor doping and aging effect of p-ZnO:(Na, N) nanorod thin films by spray pyrolysis

    Science.gov (United States)

    Swapna, R.; Amiruddin, R.; Santhosh Kumar, M. C.

    2014-01-01

    An attempt has been made to realize p-type ZnO by dual acceptor doping (Na-N) into ZnO thin films. Na and N doped ZnO thin films of different concentrations (0 to 8 at.%) have been grown by spray pyrolysis at 623 K. The grown films on glass substrate have been characterized by X-ray diffraction (XRD), Hall measurement, UV-Vis spectrophotometer, Photoluminescence (PL) and Energy dispersive spectroscopy (EDS) to validate the p-type conduction. The surface morphology and roughness of the ZnO:(Na, N) films are studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. Hall measurement shows that all the films exhibit p-type conductivity except for 0 at.% Na-N doped ZnO film. The obtained resistivity (5.60×10-2 Ω cm) and hole concentration (3.15×1018 cm-3) for the best dual acceptor doped film is 6 at.%. It has been predicted that (NaZn-NO) acceptor complex is responsible for the p-type conduction. The p-type conductivity of the ZnO:(Na, N) films is stable even after 6 months. The crystallinity of the films has been studied by XRD. Energy dispersive spectroscopy (EDS) confirms the presence of Na and N in 6 at.% ZnO:(Na, N) film. Photoluminescence (PL) spectra of ZnO:(Na, N) films show NBE and deep level emissions in the UV and visible regions, respectively. The ZnO:(Na, N) films exhibit a high transmittance about 90% in the visible region.

  6. Synthesis and characterization of nanosized calcium phosphates by flame spray pyrolysis, and their effect on osteogenic differentiation of stem cells

    International Nuclear Information System (INIS)

    The present study evaluates the synthesis of biocompatible osteoconductive and osteoinductive nano calcium phosphate (CaP) particles by industrially applied, aerosol-derived flame spray pyrolysis method for biomedical field. Calcium phosphate nanoparticles were produced in a range of calcium-to-phosphorus ratio, (1.20–2.19) in order to analyze the morphology and crystallinity changes, and to test the bioactivity of particles. The characterization results confirmed that nanometer-sized, spherical calcium phosphate particles were produced. The average primary particle size was determined as 23 nm by counting more than 500 particles in TEM pictures. XRD patterns, HRTEM, SAED, and SEM analyses revealed the amorphous nature of the as-prepared nano calcium phosphate particles at low Ca/P ratios. Increases in the specific surface area and crystallinity were observed with the increasing Ca/P ratio. TGA–DTA analysis showed that the thermally stable crystal phases formed after 700 °C. Cell culture studies were conducted with urine-derived stem cells that possess the characteristics of mesenchymal stem cells. Synthesized amorphous nanoparticles did not have cytotoxic effect at 5–50 μg/ml concentration range. Cells treated with the as-prepared nanoparticles had higher alkaline phosphatase (ALP) enzyme activity than control cells, indicating osteogenic differentiation of cells. A slight decrease in ALP activity of cells treated with two highest Ca:P ratios at 50 μg/ml concentration was observed at day 7. The findings suggest that calcium phosphate nanoparticles produced in this work have a potential to be used as biomaterials in biomedical applications

  7. Optical properties of ZnMgO films grown by spray pyrolysis and their application to UV photodetection

    Science.gov (United States)

    Lopez-Ponce, M.; Hierro, A.; Marín-Borrás, V.; Tabares, G.; Kurtz, A.; Albert, S.; Agouram, S.; Muñoz-Sanjosé, V.; Muñoz, E.; Ulloa, J. M.

    2015-10-01

    This work presents a comprehensive optical characterization of Zn1-xMgxO thin films grown by spray pyrolysis (SP). Absorption measurements show the high potential of this technique to tune the bandgap from 3.30 to 4.11 eV by changing the Mg acetate content in the precursor solution, leading to a change of the Mg-content ranging from 0 up to 35%, as measured by transmission electron microscopy-energy dispersive x-ray spectroscopy. The optical emission of the films obtained by cathodoluminescence and photoluminescence spectroscopy shows a blue shift of the peak position from 3.26 to 3.89 eV with increasing Mg incorporation, with a clear excitonic contribution even at high Mg contents. The linewidth broadening of the absorption and emission spectra as well as the magnitude of the observed Stokes shift are found to significantly increase with the Mg content. This is shown to be related to both potential fluctuations induced by pure statistical alloy disorder and the presence of a tail of band states, the latter dominating for medium Mg contents. Finally, metal-semiconductor-metal photodiodes were fabricated showing a high sensitivity and a blue shift in the cut-off energy from 3.32 to 4.02 eV, i.e., down to 308 nm. The photodiodes present large UV/dark contrast ratios (102 - 107), indicating the viability of SP as a growth technique to fabricate low cost (Zn, Mg)O-based UV photodetectors reaching short wavelengths.

  8. Smart Windows, Switchable between Transparent, Mirror, and Black States, Fabricated Using Rough and Smooth Indium Tin Oxide Films Deposited by Spray Chemical Vapor Deposition

    Science.gov (United States)

    Onodera, Ryou; Seki, Yoshiyuki; Seki, Shigeyuki; Yamada, Katsumi; Sawada, Yutaka; Uchida, Takayuki

    2013-02-01

    Two types of indium-tin oxide films, rough and smooth, with an average grain size of 434 and 71 nm, respectively, were deposited by spray pyrolysis chemical vapor deposition. Using both these films, we fabricated glare tunable transparent electrochemical devices exhibiting reversible optical changes between transparent, mirror, and black states, without any treatments. Under zero bias conditions, the transmittance of the transparent state reached 81.1% at 700 nm. With a bias of -2.5 V, the reflectance of the mirror state reached 82.0% at 700 nm. The total transmittances in the mirror and black state amounted to 0.6% in the visible range.

  9. The influence of urea on the formation process of BiPbSrCaCuO superconducting ceramics synthesized by spray pyrolysis method

    International Nuclear Information System (INIS)

    The influence of urea on the formation process in the Bi-Pb-Sr-Ca-Cu-O system, as well as, on the final high Tc phase content and morphology of the powders obtained by spray pyrolysis method was studied. The process involves aerosol formation from common nitrate solutions (with and without urea addition) using ultrasonic atomizer operated at 1.7 MHz and control over aerosol decomposition up to 840 C. It was shown that the presence of urea in the precursor solutions promotes a faster phase transformation, improves homogeneity, reduces substantially the mean particle size and affects the resulting morphology of powders. (orig.)

  10. Indium-Nitrogen Codoped Zinc Oxide Thin Film Deposited by Ultrasonic Spray Pyrolysis on n-(111) Si Substrate: The Effect of Film Thickness

    OpenAIRE

    Cheng-Chang Yu; Wen-How Lan; Kai-Feng Huang

    2014-01-01

    Indium-nitrogen codoped zinc oxide (INZO) thin films were fabricated by spray pyrolysis deposition technique on n-(111) Si substrate with different film thicknesses at 450°C using a precursor containing zinc acetate, ammonium acetate, and indium nitrate with 1 : 3 : 0.05 at.% concentration. The morphology and structure studies were carried out by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The grain size of the films increased when increasing the film thickness. From XRD ...

  11. Tailoring of optical band gap by varying Zn content in Cd1-xZnxS thin films prepared by spray pyrolysis method

    Science.gov (United States)

    Kumar, Vipin; Sharma, D. K.; Agrawal, Sonalika; Sharma, Kapil K.; Dwivedi, D. K.; Bansal, M. K.

    2016-05-01

    Cd1-XZnXS thin films (X = 0.2, 0.4, 0.6, 0.8) have been grown on glass substrate by spray pyrolysis technique using equimolar concentration aqueous solution of cadmium chloride, zinc acetate and thiourea. Prepared thin films have been characterized by UV-VIS spectrophotometer. The optical band gap of the films has been studied by transmission spectra in wavelength range 325-600nm. It has been observed that optical band gap increases with increasing zinc concentration. The optical band gap of these thin films varies from 2.59 to 3.20eV with increasing Zn content.

  12. Fabrication of Bi-Doped TiO2 Spheres with Ultrasonic Spray Pyrolysis and Investigation of Their Visible-Light Photocatalytic Properties

    Directory of Open Access Journals (Sweden)

    Jianhui Huang

    2012-01-01

    Full Text Available Bismuth-doped TiO2 submicrospheres were synthesized by ultrasonic spray pyrolysis. The prepared bismuth-doped titania was characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM, UV-visible diffuse reflectance spectroscopy (UV-vis DRS, and X-ray photoelectron spectroscopy (XPS. Aqueous photocatalytic activity was evaluated by the decomposition of methyl orange under visible-light irradiation. The results indicate that doping of bismuth remarkably affects the phase composition, crystal structure, and the photocatalytic activity. The sample with 2% Bi exhibits the optimum photocatalytic activity.

  13. Influence of optical properties of ZnO thin-films deposited by spray pyrolysis and RF magnetron sputtering on the output performance of silicon solar cell

    International Nuclear Information System (INIS)

    ZnO thin-films were deposited by spray pyrolysis and RF magnetron sputtering techniques. The optical reflection of these thin-films is measured using UV-Vis spectrophotometer. The measured optical reflection data is used in PC-1D simulation software to study the output performance of commercial silicon wafer-based solar cell. As far as optical performance is concerned it could be demonstrated that the sprayed ZnO thin-film under laboratory conditions show equivalent performance compared to sputtered ZnO thin-film. The influence of optical properties of 65 nm thick zinc oxide thin-films deposited by vacuum and non-vacuum techniques on quantum efficiency and IV characteristics of commercial silicon-wafer based solar cell is studied and reported here.

  14. Magneto caloric effect in nebulized spray pyrolysis synthesized nano crystalline La0.67Ca0.33Mn0.9V0.1O3

    International Nuclear Information System (INIS)

    Full text: Nanopowders of La0.67Ca0.33Mn0.9V0.1O3, was prepared by nebulized spay pyrolysis. Previous investigations on the same material has used solid state technique and sol-gel techniques to synthesize La0.67Ca0.33Mn0.9V0.1O3. But both the synthesis techniques failed to achieve phase purity for La0.67Ca0.33Mn0.9V0.1O3. Hence in the present investigation, Nebulized spray pyrolysis technique has been used to prepare La0.67Ca0.33Mn0.9V0.1O3. In nebulized spray pyrolysis, a precursor of cation and citric acid is prepared as a clear solution in methanol. The clear solution is converted into a fine spray using a Nebulizer. Fine spray particles are moved through a furnace set at predetermined temperature using oxygen flow. Fine spray particles undergo reaction in the furnace in the presence of oxygen producing nanosized powder agglomerates which are collected at a collector positioned at the en of the tube using a vacuum pump. At the end of the process, the powder collected will be analyzed for particle size and morphology. The structure of the compounds analyzed using X-ray powder diffractometer. The X-ray powder diffraction (XRD) patterns at room temperature showed that all synthesized samples are single phase. The structure refinement of the XRD pattern was further performed by the Reitveld analysis using X'pert plus software. The particle size is calculated from XRD using Debye Scherrer formula and is confirmed by TEM analysis. Highly uniform nano particles of average particle size of 30-39 nm was synthesized by this method. The magneto caloric effect is determined by VSM. The value of magneto caloric effect has been determined from the measurement of magnetic entropy change as a function of temperature and external magnetic field

  15. Ceria based protective coatings for steel interconnects prepared by spray pyrolysis

    DEFF Research Database (Denmark)

    Szymczewska, Dagmara; Molin, Sebastian; Chen, Ming;

    2014-01-01

    Stainless steels can be used in solid oxide fuel/electrolysis stacks as interconnects. For successful long term operation they require protective coatings, that lower the corrosion rate and block chemical reactions between the interconnect and adjacent layers of the oxygen or the hydrogen electro...... to deposit thin (~400 nm), continuous CeO2 layers on Crofer 22 APU steel substrates. Influence of the deposition parameters on layer quality is elucidated in this work....

  16. Influence of solvent on the morphology and microstructure of YSZ films obtained by spray pyrolysis technique; Influencia do solvente na morfologia e microestrutura de filmes de YSZ obtidos pela tecnica spray pirolise

    Energy Technology Data Exchange (ETDEWEB)

    Falcade, T.; Oliveira, G.B.; Mueller, I.L.; Malfatti, C.F., E-mail: tiagocoti@gmail.co, E-mail: celia.malfatti@ufrgs.b [Universidade Federal do Rio Grande do Sul (LAPEC/PPGEM/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-graduacao em Engenharia de Minas. Lab. de Pesquisa em Corrosao; Tarrago, D.P.; Sousa, V.C.; Bergmann, C.P. [Universidade Federal do Rio Grande do Sul (PPGEM/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-graduacao em Engenharia de Minas; Souza, M.M.V.M. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2010-07-01

    This work aims to investigate the influence of solvent used for the deposition of thin films of yttria stabilized zirconia (YSZ) on porous substrate. The films were obtained directly on the porous LSM substrate by spray pyrolysis technique, which consists of spraying a precursor solution containing salts of zirconium (Zr (C{sub 6}H{sub 7}O{sub 2}) 4) and yttrium (YCl{sub 3}.6H{sub 2}O), dissolved in specific solvents, on the heated substrate. The use of solvents with different boiling points and viscosity aims the optimization of experimental operating parameters to obtain homogeneous and dense films suitable for application as electrolyte in fuel cells, solid oxide (SOFC). The films were characterized by scanning electron microscopy, infrared spectroscopy and X-ray diffraction. (author)

  17. Substrate Temperature Effect on Charge Transport Performance of ZnO Electron Transport Layer Prepared by a Facile Ultrasonic Spray Pyrolysis in Polymer Solar Cells

    Directory of Open Access Journals (Sweden)

    Jiang Cheng

    2015-01-01

    Full Text Available A novel ultrasonic spray pyrolysis for high-quality ZnO films based on zinc-ammonia solution was achieved in air. To investigate the structural and optical properties as well as the performance of polymer solar cells (PSCs, ZnO films at different substrate temperatures and thicknesses were prepared. The performance of poly(3-hexylthiophene:[6,6]-phenyl C61-butyric acid methyl ester (P3HT:PCBM based PSC was found to be improved due to the ZnO films. The crystal structure and roughness of the ZnO films fabricated at different temperatures were found to affect the performance of PSCs. The optimized power conversion efficiency was found to be maximum for PSCs with ZnO films prepared at 200°C. The growth process of these ZnO films is very simple, cost-effective, and compatible for larger-scale PSC preparation. The precursor used for spray pyrolysis is environmentally friendly and helps to achieve ZnO film preparation at a relative low temperature.

  18. Structural changes in ZrO{sub x}N{sub y}/ZrO{sub 2} coatings deposited through spray pyrolysis-nitriding

    Energy Technology Data Exchange (ETDEWEB)

    Cubillos, G. I.; Olaya, J. J. [Universidad Nacional de Colombia, Av. Carrera 30 No. 45-03, 11321 Bogota (Colombia); Bethencourt, M. [Universidad de Cadiz, Campus de Excelencia Internacional del Mar, Av. Republica de Saharaui, E-11510 Puerto Real, Cadiz (Spain); Cifredo, G.; Blanco, G., E-mail: gcubillos@unal.edu.co [Universidad de Cadiz, Facultad de Ciencias, Campus Rio San Pedro, 11510 Puerto Real, Cadiz (Spain)

    2014-07-01

    Thin films of zirconium oxynitride were deposited on stainless steel 316l and characterized through ultrasonic spray pyrolysis-nitriding (Ups-N). Initially, thin films of ZrO{sub 2} are deposited using ultrasonic spray pyrolysis, and later ZrO{sub 2} films were nitrided in a NH{sub 3} atmosphere. We analyzed the effect of some variables, such as substrate temperature, flow ratio, and time of the production of coatings and their influence on the structure of the films. The characterization was carried out using X-ray diffraction (XRD) spectroscopy, X-ray photoelectron (XP S) and scanning electron microscopy (Sem). Films that were grown using the Ups method exhibited a tetragonal zirconia polycrystalline structure with preferential orientation in plane. These films, after being nitrided in an atmosphere of anhydrous ammonia at 1023 K, go through two processes: a phase transition from tetragonal to monoclinic, and later the formation of zirconium oxynitride rhombohedral ZrO{sub x}N{sub y}. (Author)

  19. Eu-doped B2O3-ZnO-PbO glass phosphor powders with spherical shape and fine size prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Eu-doped B2O3-ZnO-PbO glass phosphor powders with spherical shape and fine size were directly prepared by spray pyrolysis. The glass phosphor powders prepared at a temperature of 1100 C had broad XRD peak at around 28 . One glass phosphor powder was formed from one droplet at the preparation temperature range from 900 to 1100 C. The mean size of the glass phosphor powders was 0.75 μm. The glass transition temperature (Tg) of the glass phosphor powders prepared by spray pyrolysis was 378.5 C. The excitation spectrum of the glass phosphor powders prepared at the optimum preparation temperature of 1100 C had bands at 362, 381, 392, 463, 525, and 532 nm. The glass phosphor powders had emission spectra with bands at 579, 614, and 653 nm. The glass phosphor powders with doping concentration of Eu of 7 wt% had the maximum photoluminescence intensity. The glass phosphor layer formed from the glass phosphor powders had high transparencies above 90%. (orig.)

  20. Electrostatic spray pyrolysis of LiNi0.5Mn1.5O4 films for 3D Li-ion microbatteries

    International Nuclear Information System (INIS)

    Electrostatic spray pyrolysis has been used to produce high voltage LiNi0.5Mn1.5O4 thin film electrodes for 3D Li-ion microbattery application. The influence of the synthesis parameters on the structure, texture and electrochemical behavior of the produced electrode has been investigated using X-ray diffraction, scanning and transmission electron microscopies, cyclic voltammetry and galvanostatic measurements. A specific capacity of 135 mAh.g−1 can be achieved without any electronic conducting additive in the electrode. Moreover, a controlled deposition on a flat and 3D architecture substrate has been demonstrate and discussed showing the potential of such a deposition technique in the production of 3D all solid state Li-ion batteries. - Highlights: ► Electrostatic spray pyrolysis for 1-step Li-ion micro battery electrode deposition. ► LiNi0.5Mn1.5O4 thin film electrodes. ► Electrochemical performances related to the film texture. ► Controlled deposition on flat and 3D substrate.

  1. One-Pot Synthesis of CoSex -rGO Composite Powders by Spray Pyrolysis and Their Application as Anode Material for Sodium-Ion Batteries.

    Science.gov (United States)

    Park, Gi Dae; Kang, Yun Chan

    2016-03-14

    A simple one-pot synthesis of metal selenide/reduced graphene oxide (rGO) composite powders for application as anode materials in sodium-ion batteries was developed. The detailed mechanism of formation of the CoSe(x)-rGO composite powders that were selected as the first target material in the spray pyrolysis process was studied. The crumple-structured CoSe(x)-rGO composite powders prepared by spray pyrolysis at 800 °C had a crystal structure consisting mainly of Co0.85 Se with a minor phase of CoSe2. The bare CoSe(x) powders prepared for comparison had a spherical shape and hollow structure. The discharge capacities of the CoSe(x)-rGO composite and bare CoSe(x) powders in the 50th cycle at a constant current density of 0.3 A g(-1) were 420 and 215 mA h g(-1), respectively, and their capacity retentions measured from the second cycle were 80 and 46%, respectively. The high structural stability of the CoSe(x)-rGO composite powders for repeated sodium-ion charge and discharge processes resulted in superior sodium-ion storage properties compared to those of the bare CoSe(x) powders. PMID:26864320

  2. Identification of spinel phase in the sintered body from MgO- and NiO-doped Al2O3 powders by spray pyrolysis method

    International Nuclear Information System (INIS)

    Powders prepared by spray pyrolysis method are expected to have the compositional homogeneity and homogeneous distribution of additives. Pure, MgO doped and NiO doped Al2O3 powders were synthesized by spray pyrolysis method at 1,000 deg C. Sintered specimens were prepared by firing at 1,600, 1,650 and 1,700 deg C for 2 hrs. with their calcined powders of 1,100 deg C for 1 hr. The microstructure of pure Al2O3 sintered specimen showed large grains and grain-boundary pores, and its relative density was about 91% even thought it was fired at 1,700 deg C, 2 hrs. 0.25 wt% MgO or 0.3 wt% NiO doped Al2O3 prevented discontinuous grain growth and eliminated residual pores, and allowed the specimen to densify to near a theoretical density. More MgO or NiO doping into Al2O3 impeded the grain growth and included many pores. According to SAD(selected area diffraction) and EDS analysis of sintered Al2O3 bodies doped with 0.25, 5.0 wt% MgO and 0.3, 5.0 wt% NiO, the second phase Mg-Al spinel particles and Ni-Al spinel particles were observed at grain boundary and inside Al2O3 grains. (Author)

  3. The effect of oxidation time on the parameters of ITO/Si solar cell prepared by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Kandil, S. A; Afifi, H. H; El-hefnawi, S. H; Eliwa, A.Y [Electronic Research Institute, Dokki, Cairo (Egypt)

    2000-07-01

    The indium tin oxide (ITO/N-Si) solar cells have been fabricated by spray pyrolysis technique. The silicon wafers are heated at 500 Celsius degrees with different oxidation time (2-20 min). The best values obtained for ITO/Si solar cell output parameters; open circuit voltage V{sub o}c, short circuit current density J{sub s}c, fill factor FF and efficiency {eta} are 0.48 V, 15 mA/cm{sup 2}, 0.7 and 10.1% respectively. The preceding results were obtained under conditions of 5 minutes oxidation time and the surface area equal to 8 mm{sup 2} when the light intensity is 50 MW/ cm{sup 2}. The values of V{sub o}c, J{sub s}c, FF and {eta} are affected strongly by the varying the oxidation time. This paper is devoted to explain the effect of the interfacial layer SiO{sub 2} thickness on the ITO/Si solar cell parameters as deduced from the I-V and C-V measurements. [Spanish] Mediante tecnicas de pirolisis de dispersion se han fabricado celdas solares de oxido de Indio estanado ITO/N-Si. Las obleas de silicon se calientan a 500 con diferentes tiempos de oxidacion (2-20 min.) Los mejores valores obtenidos para los parametros de produccion de las celdas solares ITO-Si de voltaje en circuito abierto V{sub o}c densidad de corriente de corto circuito J{sub s}c factor de llenado FF y eficiencia {eta} son de 0.48 V, 15 mA/cm{sup 2}, 0.7% y 10.1% respectivamente los resultados precedentes se obtuvieron bajo condiciones de 5 minutos de tiempo de oxidacion y la superficie del area=8 mm{sup 2} cuando la intensidad de la luz es de 50mW/Cm{sup 2}. Los valores de V{sub o}c, J{sub s}c, FF y {eta} se afectan fuertemente por la variacion del tiempo de oxidacion. Este articulo esta dedicado a explicar el efecto del espesor de la capa interfacial de SiO{sub 2} en los parametros de la celda solar ITO-Si como se deduce de las mediciones I-V y C-V.

  4. Effect of pyrolysis temperature on the chemical oxidation stability of bamboo biochar.

    Science.gov (United States)

    Chen, Dengyu; Yu, Xinzhi; Song, Chao; Pang, Xiaoli; Huang, Jing; Li, Yanjun

    2016-10-01

    Biochar produced by biomass pyrolysis has the advantage of carbon sequestration. However, some of the carbon atoms in biochar are not very stable. In this study, the effect of pyrolysis temperature on the chemical oxidation stability of bamboo biochar was investigated using the atomic ratios of H/C and O/C, Fourier transform infrared spectroscopy, and potassium dichromate (K2Cr2O7) oxidation spectrophotometric method. The results show that the carbon yield and ratios of H/C and O/C decreased from 71.72%, 0.71, and 0.32 to 38.48%, 0.22, and 0.06, respectively, as the temperature was increased from 300°C to 700°C. Moreover, the main oxygen-containing functional groups gradually decreased, while the degree of aromatization increased accordingly. The biochar showed a better stability at a higher pyrolysis temperature. The proportion of carbon loss, i.e., the amount of oxidized carbon with respect to the total carbon of the biochar, decreased from 16.52% to 6.69% with increasing temperature. PMID:27481469

  5. Synthesis of AgInSnS4 thin films by adding tin (Sn) into the chalcopyrite structure of AgInS2 using spray pyrolysis

    International Nuclear Information System (INIS)

    AgInSnS4 thin films were prepared by adding a tin salt to the starting solution used for preparing chalcopyrite AgInS2 thin films by spray pyrolysis The AgInSnS4 films were grown at substrate temperatures in the 300-400 oC range, using an alcoholic solution comprised of silver acetate, indium chloride, tin chloride and thiourea. The tin chloride content in the starting solution was gradually varied in terms of the molar ratio x = [Sn]/([S] + [Ag]) from 0 to 0.5 to obtain Sn-doped chalcopyrite AgInS2 (x 4 (x = 0.2-0.4). X-ray diffraction studies indicated that AgInSnS4 has a cubic spinel-like structure with lattice parameter of 10.77 A. All AgInSnS4 thin films exhibited p-type conduction, and their room temperature conductivity ranged from 10-1 to 10-2 S/cm. The conductivity versus 1/T plots for this material showed an Arrhenius-like behavior, from which two activation energies of Ea1 = 0.23-0.40 eV and Ea2 = 0.07-0.20 eV were determined. These results suggest that the grain boundary scattering and the ionization of shallow acceptors dominate the charge carrier transport in the sprayed AgInSnS4 thin films. The AgInSnS4 absorption spectrum revealed an energy gap around Eg = 1.89 eV, which was associated to direct-allowed transitions. To our knowledge, the quaternary compound has been prepared for the first time using spray pyrolysis.

  6. Synthesis and electrochemical properties of Li-rich spinel type LiMn2O4 powders by spray pyrolysis using aqueous solution of manganese carbonate

    International Nuclear Information System (INIS)

    Research highlights: → The rechargeable capacity and cycle performance of the cathode for lithium ion battery were significantly improved by using Li-rich LiMn2O4 powders derived from spray pyrolysis. → When manganese carbonate is used as a starting material, the industrial problem in the spray pyrolysis which the toxic gas is discharged in the powders production is overcome. Therefore, this powder preparation method is effective for the powder production of other metal oxide from liquid phase as the clean process without the toxic and corrosive gases. → It is clear that Li-rich LiMn2O4 cathode exhibits excellent cycle stability superior to metal doped LiMn2O4. → Li1.09Mn1.91O4 cathode exhibits also excellent cycle stability without the doping of foreign metal (Al, Cr , Mg, etc.) reported in past. - Abstract: Li-rich lithium manganese oxide (Li1.09Mn1.91O4) powders were prepared by spray pyrolysis using an aqueous solution of manganese carbonate. The aqueous solution, in which manganese carbonate was uniformly dispersed by a surfactant, was used as the starting solution. As observed by scanning electron microscopy, Li1.09Mn1.91O4 had spherical morphology with a porous microstructure and consisted of primary particles. Powder X-ray diffraction analysis revealed that the crystal phase of the Li1.09Mn1.91O4 powders was in good agreement with the spinel phase. Inductively coupled plasma analysis showed that the molar ratio of Li and Mn in the Li1.09Mn1.91O4 powders was 1.09:1.90. Through electrochemical measurements, the initial discharge capacity of a Li1.09Mn1.91O4 cathode was found to be 107 mAh/g at 1 C (99% retention after 100 cycles) and 91 mAh/g at 10 C (93% retention after 100 cycles). The retention ratio of discharge capacity remained greater than 90%, although capacity loss was observed up to 20 cycles. The Li1.09Mn1.91O4 cathode derived from carbonate solution had excellent cycling stability in comparison with the LiMn2O4 cathode derived from nitrate

  7. Pyrolysis of triglyceride materials for the production of renewable fuels and chemicals.

    Science.gov (United States)

    Maher, K D; Bressler, D C

    2007-09-01

    Conversion of vegetable oils and animal fats composed predominantly of triglycerides using pyrolysis type reactions represents a promising option for the production of renewable fuels and chemicals. The purpose of this article was to collect and review literature on the thermo-chemical conversion of triglyceride based materials. The literature was divided and discussed as (1) direct thermal cracking and (2) combination of thermal and catalytic cracking. Typically, four main catalyst types are used including transition metal catalysts, molecular sieve type catalysts, activated alumina, and sodium carbonate. Reaction products are heavily dependant on the catalyst type and reaction conditions and can range from diesel like fractions to gasoline like fractions. Research in this area is not as advanced as bio-oil and bio-diesel research and there is opportunity for further study in the areas of reaction optimization, detailed characterization of products and properties, and scale-up. PMID:17166713

  8. Structural and sensing properties of nanocrystalline SnO2 films deposited by spray pyrolysis from a SnCl2 precursor

    Science.gov (United States)

    Gaiduk, P. I.; Kozjevko, A. N.; Prokopjev, S. L.; Tsamis, C.; Nylandsted Larsen, A.

    2008-06-01

    We report the fabrication and characterization of tin dioxide gas sensing layers. The tin dioxide layers were synthesized using a convenient, simple and low-cost technique of spray pyrolysis. The formation of stoichiometric SnO2 layers with fine-grain structure is revealed by Rutherford backscattering spectroscopy. The microstructure, phase, nanoparticle size distribution and surface morphology were studied by transmission electron microscopy, electron diffraction and atomic force microscopy. Most of the grains were of 10 20 nm size; however, some particles were up to 100 nm in size and had a microtwin lamellae structure of SnO2 phase (cassiterite) with lattice parameters a= 0.474 nm and c= 0.319 nm. The sensitivity of the layers with respect to 1000 10000 ppm CH4 in air was obtained from both resistivity (SR) and capacity (SC) measurements at 330 °C and values of SR=5 7 and SC=22 31 were extracted.

  9. Ultrasonic spray pyrolysis of nano crystalline spinel LiMn2O4 showing good cycling performance in the 3 V range

    International Nuclear Information System (INIS)

    Spherical lithium manganese oxide spinel was synthesized by an ultrasonic spray pyrolysis method, and has been characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and electrochemical cycling at 3 V regions. The LiMn2O4 powders were composed of about 10 nm-sized primary particles. The delivered discharge capacity of the synthesized nano-material was 125 mAh g-1 between 2.4 and 3.5 V and its retention was about 96% upon 50 cycling. From the high resolution transmission electron microscopic study, it was found that structural transition of the parent material did not occur even after the 50th electrochemical cycling on the 3 V region. It seems that the reversible structural change is possible for nanocrystalline LiMn2O4 as observed by the X-ray diffraction and transition electron microscopic observations

  10. Ionization potentials of transparent conductive indium tin oxide films covered with a single layer of fluorine-doped tin oxide nanoparticles grown by spray pyrolysis deposition

    International Nuclear Information System (INIS)

    Indium tin oxide (ITO) films deposited with single layers of monodispersive fluorine-doped tin oxide (FTO) nanoparticles of several nanometers in size were grown on glass substrates by intermittent spray pyrolysis deposition using conventional atomizers. These films have significantly higher ionization potentials than the bare ITO and FTO films grown using the same technique. The ITO films covered with FTO particles of 7 nm in average size show an ionization potential of 5.01 eV, as compared with ∼4.76 and ∼4.64 eV in ITO and FTO films, respectively, which decreases as the FTO particle size increases. The ionization potentials are practically invariant against oxidation and reduction treatments, promising a wide application of the films to transparent conducting oxide electrodes in organic electroluminescent devices and light-emitting devices of high efficiencies

  11. Optical and electrical properties of p-type AgInSn xS2-x (x = 0-0.04) thin films prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    AgInSn xS2-x (x = 0-0.2) polycrystalline thin films were prepared by the spray pyrolysis technique. The samples were deposited on glass substrates at temperatures of 375 and 400 deg. C from alcoholic solutions comprising silver acetate, indium chloride, thiourea and tin chloride. All deposited films crystallized in the chalcopyrite structure of AgInS2. A p-type conductivity was detected in the Sn-doped samples deposited at 375 deg. C, otherwise they are n-type. The optical properties of AgInSn xS2-x (x 2. Low-temperature PL measurements revealed that Sn occupying an S-site could be the responsible defect for the p-type conductivity observed in AgInSn xS2-x (x < 2) thin films

  12. Aluminum oxide thin films deposited on silicon substrates from Al(NO{sub 3}){sub 3} and an organic solvent by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Frutis, M.; Alejos, T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada del IPN, Legaria 694 Col. Irrigacion, Del. Miguel Hidalgo C.P. 11500, Mexico DF (Mexico); Guzman-Mendoza, J. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada del IPN, Legaria 694 Col. Irrigacion, Del. Miguel Hidalgo C.P. 11500, Mexico DF (Mexico); Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Del. Coyoacan C.P. 04510, Mexico DF (Mexico); Garcia-Hipolito, M. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Del. Coyoacan C.P. 04510, Mexico DF (Mexico); Falcony, C. [Centro de Investigacion y de Estudios Avanzados del IPN, Apdo. Postal 14-740, 07000, Mexico DF (Mexico)

    2003-09-01

    Aluminum oxide thin films were deposited on silicon substrates at temperatures in the range from 500 to 650 C, from Al(NO{sub 3}){sub 3} dissolved in N,N-Dimethylformamide and using the spray pyrolysis technique. The films of aluminum oxide resulted stoichiometric, amorphous and optically transparent in the visible spectrum, with a refractive index close to 1.66 when a 0.2 molar solution of Al(NO{sub 3}){sub 3} was used. The films as deposited had a surface roughness as low as 3.8 nm and were almost free of Al-OH bonds, depending on the experimental deposition conditions. The best films were incorporated in a Metal-Oxide-Semiconductor structure and were able to stand electric fields up to 2 MV/cm without destructive breakdown and a dielectric constant of 7.95. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Determination of the optimal parameters for the fabrication of ZnO thin films prepared by spray pyrolysis method

    Indian Academy of Sciences (India)

    M Ardyanian; M M Bagheri-Mohagheghi; N Sedigh

    2012-04-01

    In this work, ZnO thin films have been prepared by spray pyrolysis deposition method on the glass substrates. The effect of deposition parameters, such as deposition rate, substrate temperature and solution volume has been studied by X-ray diffraction (XRD) method, UV–Vis–NIR spectroscopy, scanning electron microscopy (SEM), and electrical measurements. The XRD patterns indicate polycrystalline wurtzite structure with preferred direction along (0 0 2) planes. Thin films have transparency around 90% in the visible range. The optical band gap was determined at 3.27 eV which did not change significantly. Evolution of electrical results containing the carriers' density, sheet resistance and resistivity are in agreement with structural results. All the results suggest the best deposition parameters are: deposition rate, = 3 ml/min, substrate temperature, s = 450°C and thickness of the thin films = 110–130 nm.

  14. Blue-green-red luminescence from CeCl3- and MnCl2-doped hafnium oxide layers prepared by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Hafnium oxide films doped with CeCl3 and/or MnCl2, and deposited at 300 deg. C by an ultrasonic spray pyrolysis process, were characterized using x-ray diffraction (XRD), energy-dispersive spectroscopy and photoluminescence. The XRD results revealed that the films are predominantly amorphous. The weak green-red emission of Mn2+ is enhanced through an efficient energy transfer from Ce3+ to Mn2+ ions. Spectroscopic data revealed that the energy transfer is nonradiative in nature and it could occur in Ce3+ and Mn2+ clusters through a short-range interaction mechanism. The efficiency of this transfer increases with the Mn2+ ion concentration, so that an efficiency of about 78% is attained for a 5 at.% of MnCl2 concentration, which makes these films interesting phosphors for the design of luminescent layers with blue, green and red emissions

  15. Morphology and microstructure of textured SnO2 thin films obtained by spray pyrolysis and their effect on electrical and optical properties

    International Nuclear Information System (INIS)

    Tin dioxide thin films on glass substrate with different Zn doping levels were obtained by spray pyrolysis. Their microstructure, preferred crystallographic orientation, electrical and optical properties were extensively studied. The characterization techniques employed were scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X-ray diffraction, electrical conductivity and optical transmission measurements. It was found that the material obtained has a nano-scale texture which characteristic size and orientation strongly depend on the Zn doping level. Doping-induced variations in texture and structure modify both the electrical and optical properties of films (namely, refractive index and transparency). The results obtained are relevant for potential applications of the studied films in gas sensing and photoconductive devices

  16. The suitability of selected austenitic stainless steels and Hastelloy C276 alloys as substrates for thin film deposition using spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Al Khateeb, Shadi [Al-Balqa' Applied Univ., Al-Salt, Jordan (Jordan). Materials Engineering Dept.

    2013-03-15

    To detect the suitability of the American Iron and Steel Institute grade 304, 309, 310, 316L steels and Hastelloy C276 substrates for thin film deposition using spray pyrolysis, the substrates were pre-heated between 400-700 C and soaked for one hour. American Society for Testing and Materials standards A262-A, E and G28-A were then applied. The substrates of 304 heated at 400, 600-700 C, the 310 heated between 450-700 C and the as-received 310 were not found suitable. However it was found that the 304, 309, and 310 substrates were suitable up to 550 C, the 316L up to 700 C and the C276 up to 550 C. (orig.)

  17. Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Shasti, M.; Mortezaali, A., E-mail: mortezaali@alzahra.ac.ir; Dariani, R. S. [Department of Physics, Alzahra University, Tehran 1993893973 (Iran, Islamic Republic of)

    2015-01-14

    In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism.

  18. Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

    International Nuclear Information System (INIS)

    In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism

  19. The Controlled Single-Step Synthesis of Ag/TiO2 and Au/TiO2 by Ultrasonic Spray Pyrolysis (USP)

    Science.gov (United States)

    Bogovic, J.; Rudolf, R.; Friedrich, B.

    2016-01-01

    This article reports the synthesis of Ag/TiO2 and Au/TiO2 nanoparticles by single-step ultrasonic spray pyrolysis (USP) conducted by an investigation of the process parameters and the morphological characteristics of the obtained nanostructures. The influence of the ratio in the precursor solution, physical characteristics of used components, and temperature had a large influence on the formation of different nanoparticle morphologies. The experimental investigations were performed using classic USP equipment, with variations of the process parameters. Scanning electron microscopy, transmission electron microscopy, and focused ion beam analyses were used to characterize the complex nanostructures. Based on the obtained results, the optimal process window for the formation of the different morphologies for the Ag/TiO2 and Au/TiO2 nanoparticles is determined and the possibility of synthesis of the core-shell structures in one step by USP is confirmed.

  20. The Effect of Film Composition on the Texture and Grain Size of CuInS2 Prepared by Spray Pyrolysis

    Science.gov (United States)

    Jin, Michael H.-C.; Banger, Kulbinder K.; Harris, Jerry D.; Hepp, Aloysius F.

    2003-01-01

    CuInS2 was deposited by spray pyrolysis using single-source precursors synthesized in-house. Films with either (112) or (204/220) preferred orientation always showed Cu-rich and In-rich composition respectively. The In-rich (204/220)-oriented films always contained a secondary phase evaluated as an In-rich compound, and the hindrance of (112)-oriented grain growth was confirmed by glancing angle X-ray diffraction. In conclusion, only the Cu-rich (112)-oriented films with dense columnar grains can be prepared without the secondary In-rich compound. The effect of extra Cu on the grain size and the solar cell results will be also presented.

  1. Effect of oxidation on the chemical nature and distribution of low-temperature pyrolysis products from bituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; MacPhee, J.A.; Vancea, L.; Ciavaglia, L.A.; Nandi, B.N.

    1983-04-01

    Two bituminous coals, a high volatile Eastern Canadian and a medium volatile Western Canadian, were used to investigate the effect of oxidation on yields and chemical composition of gases, liquids and chars produced during coal pyrolysis. Pyrolysis experiments were performed at 500 C using the Fischer assay method. Mild oxidation of coals resulted in a decrease of liquid hydrocarbon yields. Further coal oxidation increased the proportion of aromatic carbon in liquid products as determined by N.M.R. and also increased the content of oxygen in liquid products. The content of oxygen in chars was markedly lower than in corresponding coals. An attempt is made to explain reactions occurring during oxidation and subsequent pyrolysis of coal on the basis of differences in chemical composition of gases, liquids and chars. (19 refs.)

  2. Effect of oxidation on the chemical nature and distribution of low-temperature pyrolysis products from bituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; Ciavaglia, L.A.; MacPhee, J.A.; Nandi, B.N.; Vancea, L.

    1983-04-01

    Two bituminous coals, a high volatile Eastern Canadian and a medium volatile Western Canadian, were used to investigate the effect of oxidation on yields and chemical composition of gases, liquids and chars produced during coal pyrolysis. Pyrolysis experiments were performed at 500/sup 0/C using the Fischer assay method. Mild oxidation of coals resulted in a decrease of liquid hydrocarbon yields. Further coal oxidation increased the proportion of aromatic carbon in liquid products as determined by n.m.r., and also increased the content of oxygen in liquid products. The content of oxygen in chars was markedly lower than in corresponding coals. An attempt is made to explain reactions occurring during oxidation and subsequent pyrolysis of coal on the basis of differences in chemical composition of gases, liquids and chars.

  3. Synthesis and characterization of nano-V2O5 by flame spray pyrolysis, and its cathodic performance in Li-ion rechargeable batteries

    International Nuclear Information System (INIS)

    Highlights: • Nano-V2O5 was produced by flame spray pyrolysis to test its potential as a cathode material in Li-ion rechargeable batteries. • BET, XRD, SEM, TEM-EDS-SAED and HRTEM techniques were used to characterize V2O5 nano-particles for the investigation of their structural and morphological properties. • Electrochemical measurements showed high rate reversibility, low polarisation during lithium insertion/extraction, stable interfacial resistance and high electrical conductivity. - Abstract: Vanadium pentoxide (V2O5) nano-particles have been synthesized by flame spray pyrolysis method to investigate their cathodic performance in Li-ion rechargeable batteries. They were characterized by surface area (Brunauer–Emmett–Teller, BET method), scanning electron microscopy (SEM), transmission electron microscopy–energy dispersive spectrometry (TEM–EDS), selected area electron diffraction (SAED), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) methods. Spherical, crystalline (orthorhombic) nano-V2O5 particles were produced. The electrochemical tests, including cyclic voltammetry (CV) and ac impedance spectroscopy (IS), were performed to obtain the reversibility and conductivity kinetic parameters. From IS measurements, nano film conductivity was found to be 2.42 × 10−6 S cm−1, which is 10-fold higher than the commercial micro-particle V2O5 counterparts. From spectra, it was also found that the interfacial resistance became stable after 7200 s. The impedance results indicated that the rate of reaction at the interphase was controlled by both charge transfer and diffusion processes. The cyclic voltammogram showed high reversibility rate and low polarization

  4. Synthesis and characterization of nano-V{sub 2}O{sub 5} by flame spray pyrolysis, and its cathodic performance in Li-ion rechargeable batteries

    Energy Technology Data Exchange (ETDEWEB)

    Sel, Sinem [Department of Chemical Engineering, Kocaeli University, Kocaeli-Izmit 41380 (Turkey); Duygulu, Ozgur [Materials Institute, TUBITAK Marmara Research Center, Kocaeli- Gebze 41470 (Turkey); Kadiroglu, Umit [Department of Chemistry, Kocaeli University, Kocaeli-Izmit 41380 (Turkey); Machin, Nesrin E., E-mail: nesrinmachin@gmail.com [Department of Chemical Engineering, Kocaeli University, Kocaeli-Izmit 41380 (Turkey)

    2014-11-01

    Highlights: • Nano-V{sub 2}O{sub 5} was produced by flame spray pyrolysis to test its potential as a cathode material in Li-ion rechargeable batteries. • BET, XRD, SEM, TEM-EDS-SAED and HRTEM techniques were used to characterize V{sub 2}O{sub 5} nano-particles for the investigation of their structural and morphological properties. • Electrochemical measurements showed high rate reversibility, low polarisation during lithium insertion/extraction, stable interfacial resistance and high electrical conductivity. - Abstract: Vanadium pentoxide (V{sub 2}O{sub 5}) nano-particles have been synthesized by flame spray pyrolysis method to investigate their cathodic performance in Li-ion rechargeable batteries. They were characterized by surface area (Brunauer–Emmett–Teller, BET method), scanning electron microscopy (SEM), transmission electron microscopy–energy dispersive spectrometry (TEM–EDS), selected area electron diffraction (SAED), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) methods. Spherical, crystalline (orthorhombic) nano-V{sub 2}O{sub 5} particles were produced. The electrochemical tests, including cyclic voltammetry (CV) and ac impedance spectroscopy (IS), were performed to obtain the reversibility and conductivity kinetic parameters. From IS measurements, nano film conductivity was found to be 2.42 × 10{sup −6} S cm{sup −1}, which is 10-fold higher than the commercial micro-particle V{sub 2}O{sub 5} counterparts. From spectra, it was also found that the interfacial resistance became stable after 7200 s. The impedance results indicated that the rate of reaction at the interphase was controlled by both charge transfer and diffusion processes. The cyclic voltammogram showed high reversibility rate and low polarization.

  5. Influence of the spray pyrolysis seeding and growth parameters on the structure and optical properties of ZnO nanorod arrays

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez, Juan, E-mail: jrodriguez@uni.edu.pe [Facultad de Ciencias, Universidad Nacional de Ingeniería, P.O. Box 31-139, Lima 31 (Peru); Feuillet, Guy [CEA Grenoble/LETI, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Donatini, Fabrice [Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble (France); CNRS, Inst NEEL, F-38042 Grenoble (France); Onna, Diego [DQIAQF-INQUIMAE, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, 1428 Buenos Aires (Argentina); Sanchez, Luis [Facultad de Ciencias, Universidad Nacional de Ingeniería, P.O. Box 31-139, Lima 31 (Peru); Candal, Roberto [DQIAQF-INQUIMAE, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, 1428 Buenos Aires (Argentina); ECyT, 3iA, Universidad Nacional de San Martín, Martín de Irigoyen N° 3100 (1650), San Martín, Pcia de Buenos Aires (Argentina); Marchi, M. Claudia [DQIAQF-INQUIMAE, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, 1428 Buenos Aires (Argentina); CMA, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. I, 1428 Buenos Aires (Argentina); Bilmes, Sara A. [DQIAQF-INQUIMAE, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, 1428 Buenos Aires (Argentina); Chandezon, Frédéric [University Grenoble Alpes, INAC-SPRAM, F-38000 Grenoble (France); CNRS, INAC-SPRAM, F-38000 Grenoble (France); CEA, INAC-SPRAM, F-38000 Grenoble (France)

    2015-02-01

    ZnO nanorods (NRs) were grown on fluorine doped tin oxide (FTO) substrates at low temperatures (90 °C) from Zn{sup 2+} precursors in alkaline media previously seeded with ZnO nanoparticles. These were deposited onto the FTO substrate heated at 350 °C by spray pyrolysis of a Zn acetate solution in a water ethanol mixture. The structure of seeds was tuned by the ethanol to water ratio, Γ, which controls the solvent evaporation rate of drops impinging the substrate. From a detailed characterization using a combination of scanning electron microscopy, X-ray diffraction, UV–visible absorption and cathodoluminescence spectroscopies, the dependence of the morphology and optical properties of the ZnO NRs on the seeding conditions was demonstrated. NRs grown on seeds deposited from solutions with Γ in the 0.03–0.06 range – i.e. when the surface excess of ethanol in the water–ethanol mixture has a maximum – show thinner average diameters and stacking faults due to the presence of zinc blende domains embedded into an overall wurtzite NR. They furthermore exhibit blue-shifted near band edge emission peak and a high deep level emission in cathodoluminescence. All these findings support the use of spray pyrolysis as a simple and reproducible way to control the seeds deposition, influencing the growth, the structure and the optical properties of the final ZnO NRs. - Highlights: • ZnO pyrolytic seeds tuned by the rate of solvent evaporation. • ZnO NRs grown from tuned pyrolytic seed's structure shows diameter dependence. • ZnO NRs show stacking faults due to the presence of zinc blende domains.

  6. Effect of the substrate temperature on the physical properties of molybdenum tri-oxide thin films obtained through the spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, H.M. [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia); Torres, J., E-mail: njtorress@unal.edu.co [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia); Lopez Carreno, L.D. [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia); Rodriguez-Garcia, M.E. [Departamento de Nanotecnologia, Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, Queretaro, Qro., Mexico (Colombia)

    2013-01-15

    Polycrystalline molybdenum tri-oxide thin films were prepared using the spray pyrolysis technique; a 0.1 M solution of ammonium molybdate tetra-hydrated was used as a precursor. The samples were prepared on Corning glass substrates maintained at temperatures ranging between 423 and 673 K. The samples were characterized through micro Raman, X-ray diffraction, optical transmittance and DC electrical conductivity. The species MoO{sub 3} (H{sub 2}O){sub 2} was found in the sample prepared at a substrate temperature of 423 K. As the substrate temperature rises, the water disappears and the samples crystallize into {alpha}-MoO{sub 3}. The optical gap diminishes as the substrate temperature rises. Two electrical transport mechanisms were found: hopping under 200 K and intrinsic conduction over 200 K. The MoO{sub 3} films' sensitivity was analyzed for CO and H{sub 2}O in the temperature range 160 to 360 K; the results indicate that CO and H{sub 2}O have a reduction character. In all cases, it was found that the sensitivity to CO is lower than that to H{sub 2}O. - Highlights: Black-Right-Pointing-Pointer A low cost technique is used which produces good material. Black-Right-Pointing-Pointer Thin films are prepared using ammonium molybdate tetra hydrated. Black-Right-Pointing-Pointer The control of the physical properties of the samples could be done. Black-Right-Pointing-Pointer A calculation method is proposed to determine the material optical properties. Black-Right-Pointing-Pointer The MoO{sub 3} thin films prepared by spray pyrolysis could be used as gas sensor.

  7. Influence of the spray pyrolysis seeding and growth parameters on the structure and optical properties of ZnO nanorod arrays

    International Nuclear Information System (INIS)

    ZnO nanorods (NRs) were grown on fluorine doped tin oxide (FTO) substrates at low temperatures (90 °C) from Zn2+ precursors in alkaline media previously seeded with ZnO nanoparticles. These were deposited onto the FTO substrate heated at 350 °C by spray pyrolysis of a Zn acetate solution in a water ethanol mixture. The structure of seeds was tuned by the ethanol to water ratio, Γ, which controls the solvent evaporation rate of drops impinging the substrate. From a detailed characterization using a combination of scanning electron microscopy, X-ray diffraction, UV–visible absorption and cathodoluminescence spectroscopies, the dependence of the morphology and optical properties of the ZnO NRs on the seeding conditions was demonstrated. NRs grown on seeds deposited from solutions with Γ in the 0.03–0.06 range – i.e. when the surface excess of ethanol in the water–ethanol mixture has a maximum – show thinner average diameters and stacking faults due to the presence of zinc blende domains embedded into an overall wurtzite NR. They furthermore exhibit blue-shifted near band edge emission peak and a high deep level emission in cathodoluminescence. All these findings support the use of spray pyrolysis as a simple and reproducible way to control the seeds deposition, influencing the growth, the structure and the optical properties of the final ZnO NRs. - Highlights: • ZnO pyrolytic seeds tuned by the rate of solvent evaporation. • ZnO NRs grown from tuned pyrolytic seed's structure shows diameter dependence. • ZnO NRs show stacking faults due to the presence of zinc blende domains

  8. Structural, morphological, optical and gas sensing properties of pure and Ru doped SnO{sub 2} thin films by nebulizer spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Sankar, C. [Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020 (India); Ponnuswamy, V., E-mail: sankarphysics@gmail.com [Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020 (India); Manickam, M. [Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020 (India); Mariappan, R. [Department of Physics, Adhiyaman College of Engineering and Technology, Hosur 635 109 (India); Suresh, R. [Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020 (India)

    2015-09-15

    Highlights: • Ruthenium doped tin oxide thin films at 450 °C by nebulizer spray pyrolysis technique. • Films characterized by XRD, SEM, EDS, UV–Vis and gas sensing properties. • Ethanol is good sensing gas compared with acetone, methanol, 2-methoxy ethanol and ammonia gases for pure and RTO thin films. - Abstract: Tin oxide thin films doped with different concentrations of ruthenium were deposited on the glass substrates at 450 °C by nebulizer spray pyrolysis technique. The structural, morphological, thickness and optical properties of thin films were investigated by X-ray diffraction, scanning electron microscopy, stylus profilometer and ultra violet spectrometer techniques. X-ray diffraction pattern confirms the tetragonal crystal structure for pure and ruthenium doped tin dioxide thin films. Ruthenium doped tin dioxide thin films are polycrystalline in nature. Scanning electron microscopy shows the modification of surface morphology of tin dioxide films due to varying concentration of ruthenium. Largest spheres, rings and interconnected fibers are present in the scanning electron microscopy images. Energy dispersive analysis reveals the average atomic percentage of pure and ruthenium doped tin dioxide present in the films developed. Stylus profilometer was used to measure the film thickness. Pure, 5, 10 and 15 wt% ruthenium doped tin dioxide thin films are found to have 327, 349, 386 and 425 nm thickness. Optical studies divulge that the band gap energy decreases from 3.55 eV to 3.04 eV due to the increased ruthenium concentrations. Gas sensing properties of pure and ruthenium doped tin dioxide thin films have been studied for various gases.

  9. Preparation and electrochemical properties of nanocrystalline LiBxMn2−xO4 cathode particles for Li-ion batteries by ultrasonic spray pyrolysis method

    International Nuclear Information System (INIS)

    Highlights: • B substituted spinel LiMn2O4 cathodes were prepared by spray pyrolysis method. • Effects of boron content to the spinel structure were investigated. • Formation of glassy phase expands the gap between charge–discharge potentials. • LiB0.3Mn1.7O4 sample exhibits 92 mAh g−1 discharge capacity at 0.5 C rate. • B–O bonding increases the structural stability against Li+ extraction/insertion. • Stabilized spinel structure by boron substitution shows good cycling performance. - Abstract: Nanocrystalline LiBxMn2−xO4 (x = 0.1–0.4) particles are prepared by ultrasonic spray pyrolysis using lithium nitrate, manganese nitrate and boric acid at 800 °C in an air atmosphere. The materials properties are characterized by X-ray diffraction, scanning electron microscopy, and atomic absorption spectroscopy. The electrochemical behaviors are investigated with cyclic voltammetry and galvanostatic techniques. The particle characterization studies show that nanocrystalline particles have spinel structure of submicron size with spherical morphology. All boron substituted lithium manganese oxide spinels show improved cycling performance. Among them, LiB0.3Mn1.7O4 particles exhibit 92 mAh g−1 discharge capacity and 82% capacity retention after 50 cycles at a 0.5 C rate. The higher degree of atomic ordering and the avoidance of the formation of a glass phase in LiBxMn2−xO4 materials are responsible for the better electrochemical performance

  10. Structural, morphological, optical and gas sensing properties of pure and Ru doped SnO2 thin films by nebulizer spray pyrolysis technique

    International Nuclear Information System (INIS)

    Highlights: • Ruthenium doped tin oxide thin films at 450 °C by nebulizer spray pyrolysis technique. • Films characterized by XRD, SEM, EDS, UV–Vis and gas sensing properties. • Ethanol is good sensing gas compared with acetone, methanol, 2-methoxy ethanol and ammonia gases for pure and RTO thin films. - Abstract: Tin oxide thin films doped with different concentrations of ruthenium were deposited on the glass substrates at 450 °C by nebulizer spray pyrolysis technique. The structural, morphological, thickness and optical properties of thin films were investigated by X-ray diffraction, scanning electron microscopy, stylus profilometer and ultra violet spectrometer techniques. X-ray diffraction pattern confirms the tetragonal crystal structure for pure and ruthenium doped tin dioxide thin films. Ruthenium doped tin dioxide thin films are polycrystalline in nature. Scanning electron microscopy shows the modification of surface morphology of tin dioxide films due to varying concentration of ruthenium. Largest spheres, rings and interconnected fibers are present in the scanning electron microscopy images. Energy dispersive analysis reveals the average atomic percentage of pure and ruthenium doped tin dioxide present in the films developed. Stylus profilometer was used to measure the film thickness. Pure, 5, 10 and 15 wt% ruthenium doped tin dioxide thin films are found to have 327, 349, 386 and 425 nm thickness. Optical studies divulge that the band gap energy decreases from 3.55 eV to 3.04 eV due to the increased ruthenium concentrations. Gas sensing properties of pure and ruthenium doped tin dioxide thin films have been studied for various gases

  11. Luminescence optimization of Eu-doped LnAl3(BO3)4 (Ln=Y, Gd) red phosphor using spray pyrolysis

    International Nuclear Information System (INIS)

    LnAl3(BO3)4:Eu3+ (Ln=Y, Gd) red phosphor particles were prepared by spray pyrolysis and the luminescent intensity under vacuum ultraviolet (VUV) excitation was investigated by changing Eu3+ content, Y/Gd molar ratio, and boron content. The concentration quenching for Eu3+ activator was observed at 5 at%. The highest luminescent intensity at 615 nm due to the 5D0→7F2 transitions of Eu3+ was achieved when the ratio of Gd to Y was 0.55. The R/O ratio (obtained by dividing the red emission intensity at 615 nm with the orange one at 592 nm), however, was not influenced by the G/Y ratio. Using excess boron, up to 135% of the stoichiometric quantity, improved the emission intensity of LnAl3(BO3)4:Eu3+ red phosphor. According to XRD analysis, the sample prepared using boron of a stoichiometric quantity had YBO3 phase as a minor phase. Such YBO3 phase progressively disappeared with an increase in the excess quantity of boron, which was responsible for the enhancement of emission intensity. In addition, the R/O ratio became larger and larger by increasing the excess content of boron due to a reduction in the symmetry of Y site. Consequently, both the emission intensity and the color coordinate of LnAl3(BO3)4:Eu3+ red phosphors were successfully optimized in terms of the Y/Gd ratio and the excess quantity of boron in spray pyrolysis.

  12. Effect of the substrate temperature on the physical properties of molybdenum tri-oxide thin films obtained through the spray pyrolysis technique

    International Nuclear Information System (INIS)

    Polycrystalline molybdenum tri-oxide thin films were prepared using the spray pyrolysis technique; a 0.1 M solution of ammonium molybdate tetra-hydrated was used as a precursor. The samples were prepared on Corning glass substrates maintained at temperatures ranging between 423 and 673 K. The samples were characterized through micro Raman, X-ray diffraction, optical transmittance and DC electrical conductivity. The species MoO3 (H2O)2 was found in the sample prepared at a substrate temperature of 423 K. As the substrate temperature rises, the water disappears and the samples crystallize into α-MoO3. The optical gap diminishes as the substrate temperature rises. Two electrical transport mechanisms were found: hopping under 200 K and intrinsic conduction over 200 K. The MoO3 films' sensitivity was analyzed for CO and H2O in the temperature range 160 to 360 K; the results indicate that CO and H2O have a reduction character. In all cases, it was found that the sensitivity to CO is lower than that to H2O. - Highlights: ► A low cost technique is used which produces good material. ► Thin films are prepared using ammonium molybdate tetra hydrated. ► The control of the physical properties of the samples could be done. ► A calculation method is proposed to determine the material optical properties. ► The MoO3 thin films prepared by spray pyrolysis could be used as gas sensor.

  13. Computational Analysis of the Optical and Charge Transport Properties of Ultrasonic Spray Pyrolysis-Grown Zinc Oxide/Graphene Hybrid Structures.

    Science.gov (United States)

    Ali, Amgad Ahmed; Hashim, Abdul Manaf

    2016-12-01

    We demonstrate a systematic computational analysis of the measured optical and charge transport properties of the spray pyrolysis-grown ZnO nanostructures, i.e. nanosphere clusters (NSCs), nanorods (NRs) and nanowires (NWs) for the first time. The calculated absorbance spectra based on the time-dependent density functional theory (TD-DFT) shows very close similarity with the measured behaviours under UV light. The atomic models and energy level diagrams for the grown nanostructures were developed and discussed to explain the structural defects and band gap. The induced stresses in the lattices of ZnO NSCs that formed during the pyrolysis process seem to cause the narrowing of the gap between the energy levels. ZnO NWs and NRs show homogeneous distribution of the LUMO and HOMO orbitals all over the entire heterostructure. Such distribution contributes to the reduction of the band gap down to 2.8 eV, which has been confirmed to be in a good agreement with the experimental results. ZnO NWs and NRs exhibited better emission behaviours under the UV excitation as compared to ZnO NSCs and thin film as their visible range emissions are strongly quenched. Based on the electrochemical impedance measurement, the electrical models and electrostatic potential maps were developed to calculate the electron lifetime and to explain the mobility or diffusion behaviours in the grown nanostructure, respectively. PMID:27173675

  14. Computational Analysis of the Optical and Charge Transport Properties of Ultrasonic Spray Pyrolysis-Grown Zinc Oxide/Graphene Hybrid Structures

    Science.gov (United States)

    Ali, Amgad Ahmed; Hashim, Abdul Manaf

    2016-05-01

    We demonstrate a systematic computational analysis of the measured optical and charge transport properties of the spray pyrolysis-grown ZnO nanostructures, i.e. nanosphere clusters (NSCs), nanorods (NRs) and nanowires (NWs) for the first time. The calculated absorbance spectra based on the time-dependent density functional theory (TD-DFT) shows very close similarity with the measured behaviours under UV light. The atomic models and energy level diagrams for the grown nanostructures were developed and discussed to explain the structural defects and band gap. The induced stresses in the lattices of ZnO NSCs that formed during the pyrolysis process seem to cause the narrowing of the gap between the energy levels. ZnO NWs and NRs show homogeneous distribution of the LUMO and HOMO orbitals all over the entire heterostructure. Such distribution contributes to the reduction of the band gap down to 2.8 eV, which has been confirmed to be in a good agreement with the experimental results. ZnO NWs and NRs exhibited better emission behaviours under the UV excitation as compared to ZnO NSCs and thin film as their visible range emissions are strongly quenched. Based on the electrochemical impedance measurement, the electrical models and electrostatic potential maps were developed to calculate the electron lifetime and to explain the mobility or diffusion behaviours in the grown nanostructure, respectively.

  15. Chemical Synthesis Accelerated by Paper Spray: The Haloform Reaction

    Science.gov (United States)

    Bain, Ryan M.; Pulliam, Christopher J.; Raab, Shannon A.; Cooks, R. Graham

    2016-01-01

    In this laboratory, students perform a synthetic reaction in two ways: (i) by traditional bulk-phase reaction and (ii) in the course of reactive paper spray ionization. Mass spectrometry (MS) is used both as an analytical method and a means of accelerating organic syntheses. The main focus of this laboratory exercise is that the same ionization…

  16. Aromatic chemicals by iron-catalyzed hydrotreatment of lignin pyrolysis vapor.

    Science.gov (United States)

    Olcese, Roberto Nicolas; Lardier, George; Bettahar, Mohammed; Ghanbaja, Jaafar; Fontana, Sébastien; Carré, Vincent; Aubriet, Frédéric; Petitjean, Dominique; Dufour, Anthony

    2013-08-01

    Lignin is a potential renewable material for the production of bio-sourced aromatic chemicals. We present the first hydrotreatment of lignin pyrolysis vapors, before any condensation, using inexpensive and sustainable iron-silica (Fe/SiO2 ) and iron-activated carbon (Fe/AC) catalysts. Lignin pyrolysis was conducted in a tubular reactor and vapors were injected in a fixed bed of catalysts (673 K, 1 bar) with stacks to investigate the profile of coke deposit. More than 170 GC-analyzable compounds were identified by GCxGC (heart cutting)/flame ionization detector mass spectrometry. Lignin oligomers were analyzed by very high resolution mass spectrometry, called the "petroleomic" method. They are trapped by the catalytic fixed bed and, in particular, by the AC. The catalysts showed a good selectivity for the hydrodeoxygenation of real lignin vapors to benzene, toluene, xylenes, phenol, cresols, and alkyl phenols. The spent catalysts were characterized by temperature-programmed oxidation, transmission electron microscopy (TEM), and N2 sorption. Micropores in the Fe/AC catalyst are completely plugged by coke deposits, whereas the mesoporous structure of Fe/SiO2 is unaffected. TEM images reveal two different types of coke deposit: 1) catalytic coke deposited in the vicinity of iron particles and 2) thermal coke (carbonaceous particles ≈1 μm in diameter) formed from the gas-phase growth of lignin oligomers. PMID:23784799

  17. Catalytic pyrolysis-gc/ms of spirulina: evaluation of a highly proteinaceous biomass source for production of fuels and chemicals

    Science.gov (United States)

    Pyrolysis of microalgae offers a pathway towards the production of compounds derived from the thermal decomposition of triglycerides, proteins as well as lignocelluloses and their combinations thereof. When catalytically induced, this could lead to the production of fuels and chemicals including aro...

  18. Role of substrate temperature on the properties of Na-doped ZnO thin film nanorods and performance of ammonia gas sensors using nebulizer spray pyrolysis technique

    International Nuclear Information System (INIS)

    Highlights: • Na-doped ZnO films deposited on glass by nebulizer spray pyrolysis (NSP) method. • NSP method for large area coatings and good results as compared with other methods. • HR-SEM studies reveal the formation of Na-doped ZnO films consisting of nano-rods. • Na-doped ZnO films ensure their stability and suitability for gas sensors. -- Abstract: Sodium doped zinc oxide (Na:ZnO) thin films were deposited on glass substrates at substrate temperatures 300, 400 and 500 °C by a novel nebulizer spray method. X-ray diffraction shows that all the films are polycrystalline in nature having hexagonal structure with high preferential orientation along (0 0 2) plane. High resolution SEM studies reveal the formation of Na-doped ZnO films having uniformly distributed nano-rods over the entire surface of the substrates at 400 °C. The complex impedance of the ZnO nano-rods shows two distinguished semicircles and the diameter of the arcs got decreased in diameter as the temperature increases from 170 to 270 °C and thereafter slightly increased

  19. Role of substrate temperature on the properties of Na-doped ZnO thin film nanorods and performance of ammonia gas sensors using nebulizer spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Mariappan, R., E-mail: marijpr@gmail.com [Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020, Tamil Nadu (India); Department of Physics, Adhiyamaan College of Engineering, Hosur 635 109, Tamilnadu (India); Ponnuswamy, V.; Suresh, R. [Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020, Tamil Nadu (India); Suresh, P. [Materials Research Centre, Indian Institute of Science, Bangalore 560 012 (India); Chandra Bose, A. [Department of Physics, National Institute of Technology, Tiruchirappalli 620 015, Tamil Nadu (India); Ragavendar, M. [Department of Physics, KPR Institute of Engineering and Technology, Coimbatore 641 407, Tamil Nadu (India)

    2014-01-05

    Highlights: • Na-doped ZnO films deposited on glass by nebulizer spray pyrolysis (NSP) method. • NSP method for large area coatings and good results as compared with other methods. • HR-SEM studies reveal the formation of Na-doped ZnO films consisting of nano-rods. • Na-doped ZnO films ensure their stability and suitability for gas sensors. -- Abstract: Sodium doped zinc oxide (Na:ZnO) thin films were deposited on glass substrates at substrate temperatures 300, 400 and 500 °C by a novel nebulizer spray method. X-ray diffraction shows that all the films are polycrystalline in nature having hexagonal structure with high preferential orientation along (0 0 2) plane. High resolution SEM studies reveal the formation of Na-doped ZnO films having uniformly distributed nano-rods over the entire surface of the substrates at 400 °C. The complex impedance of the ZnO nano-rods shows two distinguished semicircles and the diameter of the arcs got decreased in diameter as the temperature increases from 170 to 270 °C and thereafter slightly increased.

  20. Raman spectroscopy of Cu-Sn-S ternary compound thin films prepared by the low-cost spray-pyrolysis technique.

    Science.gov (United States)

    Brus, Viktor V; Babichuk, Ivan S; Orletskyi, Ivan G; Maryanchuk, Pavlo D; Yukhymchuk, Volodymyr O; Dzhagan, Volodymyr M; Yanchuk, Igor B; Solovan, Mykhailo M; Babichuk, Iryna V

    2016-04-20

    Cu-Sn-S (CTS) thin films were deposited onto bare and molybdenum (Mo) coated glass substrates by means of the spray pyrolysis technique under different conditions. The CTS thin films obtained are shown, by means of Raman spectroscopy, to consist of two main phases: Cu2SnS3 and Cu3SnS4 as well as of the secondary phase of Cu2-xS. The electrical conductivity of the spray-deposited p-type CTS thin films under investigation is determined by two shallow acceptor levels: Ev+0.07  eV at T334  K. The material of the CTS thin films was established to be a direct-band semiconductor with the bandgap Eg=1.89  eV. The SEM and x-ray energy dispersive analysis show the surface and cross section of the CTS thin film deposited onto molybdenum-coated glass ceramics substrate with the actual atomic ratios of Cu:Sn:S being 2.9:1:2.64, which is in good agreement with the Raman spectra. Also, a small content of residual Cl atoms was found in the CTS thin films under investigation as the by-product of the pyrolytic reactions. PMID:27140123

  1. Nanocrystalline LiMn2O4 thin film cathode material prepared by polymer spray pyrolysis method for Li-ion battery

    International Nuclear Information System (INIS)

    Nanocrystalline cubic spinel lithium manganese oxide thin film was prepared by a polymer spray pyrolysis method using lithium acetate and manganese acetate precursor solution and polyethylene glycol-4000 as a polymeric binder. The substrate temperature was selected from the thermogravimetric analysis by finding the complete crystallization temperature of LiMn2O4 precursor sample. The deposited LiMn2O4 thin films were annealed at 450, 500 and 600 oC for 30 min. The thin film annealed at 600 oC was found to be the sufficient temperature to form high phase pure nanocrystalline LiMn2O4 thin film. The formation of cubic spinel thin film was confirmed by X-ray diffraction study. Scanning electron microscopy and atomic force microscopy analysis revealed that the thin film annealed at 600 oC was found to be nanocrystalline in nature and the surface of the films were uniform without any crack. The electrochemical charge/discharge studies of the prepared LiMn2O4 film was found to be better compared to the conventional spray pyrolysed thin film material.

  2. Formation of core-shell-structured Zn2SnO4-carbon microspheres with superior electrochemical properties by one-pot spray pyrolysis.

    Science.gov (United States)

    Hong, Young Jun; Kang, Yun Chan

    2015-01-14

    Core-shell structured Zn2SnO4-carbon microspheres with different carbon contents are prepared by one-pot spray pyrolysis without any further heating process. A Zn2SnO4-carbon composite microsphere is prepared from one droplet containing Zn and Sn salts and polyvinylpyrrolidone (PVP). Melted PVP moves to the outside of the composite microsphere during the drying stage of the droplet. In addition, melting of the phase separated metal salts forms the dense core. Carbonization of the phase separated PVP forms the textured and porous thick carbon shell. The discharge capacities of the core-shell structured Zn2SnO4-carbon microspheres for the 2(nd) and 120(th) cycles at a current density of 1 A g(-1) are 864 and 770 mA h g(-1), respectively. However, the discharge capacities of the bare Zn2SnO4 microspheres prepared by the same process without PVP for the 2(nd) and 120(th) cycles are 1106 and 81 mA h g(-1), respectively. The stable and reversible discharge capacities of the Zn2SnO4-carbon composite microspheres prepared from the spray solution with 15 g PVP decrease from 894 to 528 mA h g(-1) as current density increases from 0.5 to 5 A g(-1). PMID:25429709

  3. Tin sulfide (SnS) nanostructured films deposited by continuous spray pyrolysis (CoSP) technique for dye-sensitized solar cells applications

    Science.gov (United States)

    Alam, Firoz; Dutta, Viresh

    2015-12-01

    Tin sulfide (SnS) nanostructured films have been deposited on transparent conducting glass substrate using continuous spray pyrolysis (CoSP) technique using aqueous spray solution of tin chloride and thiourea. Structural, morphological and optical properties of as-synthesized SnS nanostructured films showed the formation of (1 0 1) oriented orthorhombic SnS with nanoflakes having a direct band gap of 1.40 eV. X-ray photoelectron spectroscopy (XPS) analysis confirms the formation of pure SnS with Sn in +2 oxidation state. The SnS nanostructured film has also been characterized using Brunauer-Emmett-Teller (BET) technique to determine the surface area and pore volume which are found to be 11.4 m2/g and 0.02 cm2/g, respectively. The film has been used as a counter electrode (CE) in a triiodide/iodide (I3-/I-) based dye-sensitized solar cells (DSSCs). The DSSCs of 0.25 cm2 area with SnS nanostructured CE exhibits a lower power conversion efficiency (2.0 ± 0.06%) than that for the cell with standard platinum (Pt) CE (4.5 ± 0.13%). However, the usefulness of the CoSP technique for deposition of nanostructures SnS CE film has been established in the present study.

  4. Pretreatment of empty palm fruit bunch for production of chemicals via catalytic pyrolysis.

    Science.gov (United States)

    Misson, Mailin; Haron, Roslindawati; Kamaroddin, Mohd Fadhzir Ahmad; Amin, Nor Aishah Saidina

    2009-06-01

    The effect of chemical pretreatments using NaOH, H(2)O(2), and Ca(OH)(2) on Empty Palm Fruit Bunches (EPFB) to degrade EPFB lignin before pyrolysis was investigated. Spectrophotometer analysis proved consecutive addition of NaOH and H(2)O(2) decomposed almost 100% of EPFB lignin compared to 44% for the Ca(OH)(2), H(2)O(2) system while NaOH and Ca(OH)(2) used exclusively could not alter lignin much. Next, the pretreated EPFB was catalytically pyrolyzed. Experimental results indicated the phenolic yields over Al-MCM-41 and HZSM-5 catalysts were 90 wt% and 80 wt%, respectively compared to 67 wt% yield for the untreated sample under the same set of conditions. Meanwhile, the experiments with HY zeolite yielded 70 wt% phenols. PMID:19232488

  5. Steam chemical reactivity of plasma-sprayed beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; Pawelko, R.J.; Smolik, G.R. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.; Castro, R.G. [Los Alamos National Lab., NM (United States)

    1998-07-01

    Plasma-spraying with the potential for in-situ repair makes beryllium a primary candidate for plasma facing and structural components in experimental magnetic fusion machines. Deposits with good thermal conductivity and resistance to thermal cycling have been produced with low pressure plasma-spraying (LPPS). A concern during a potential accident with steam ingress is the amount of hydrogen produced by the reactions of steam with hot components. In this study the authors measure the reaction rates of various deposits produced by LPPS with steam from 350 C to above 1,000 C. They correlate these reaction rates with measurements of density, open porosity and BET surface areas. They find the reactivity to be largely dependent upon effective surface area. Promising results were obtained below 600 C from a 94% theoretical dense (TD) deposit with a BET specific surface area of 0.085 m{sup 2}/g. Although reaction rates were higher than those for dense consolidated beryllium they were substantially lower, i.e., about two orders of magnitude, than those obtained from previously tested lower density plasma-sprayed deposits.

  6. Structural properties of In{sub 2}Se{sub 3} precursor layers deposited by spray pyrolysis and physical vapor deposition for CuInSe{sub 2} thin-film solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Figueroa, P. [Department of Electrical Engineering (SEES), Cinvestav-Zacatenco, 2508 Av. IPN, 07360 Mexico City (Mexico); IMN, UMR 6502, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes Cedex 3 (France); Painchaud, T.; Lepetit, T.; Harel, S.; Arzel, L. [IMN, UMR 6502, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes Cedex 3 (France); Yi, Junsin, E-mail: yi@skku.ac.kr [School of Information and Communication Engineering, 2066 Seobu-ro, Jangan-gu, 440-746 Suwon (Korea, Republic of); Barreau, N. [IMN, UMR 6502, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes Cedex 3 (France); Velumani, S., E-mail: velu@cinvestav.mx [Department of Electrical Engineering (SEES), Cinvestav-Zacatenco, 2508 Av. IPN, 07360 Mexico City (Mexico); School of Information and Communication Engineering, 2066 Seobu-ro, Jangan-gu, 440-746 Suwon (Korea, Republic of)

    2015-07-31

    The structural properties of In{sub 2}Se{sub 3} precursor thin films grown by chemical spray pyrolysis (CSP) and physical vapor deposition (PVD) methods were compared. This is to investigate the feasibility to substitute PVD process of CuInSe{sub 2} (CISe) films by CSP films as precursor layer, thus decreasing the production cost by increasing material-utilization efficiency. Both films of 1 μm thickness were deposited at the same substrate temperature of 380 °C. X-ray diffraction and Raman spectra confirm the formation of γ-In{sub 2}Se{sub 3} crystalline phase for both films. The PVD and CSP films exhibited (110) and (006) preferred orientations, respectively. The PVD films showed a smaller full width at half maximum value (0.09°) compared with CSP layers (0.1°). Films with the same crystalline phase but with different orientations are normally used in the preparation of high quality CISe films by 3-stage process. Scanning electron microscope cross-section images showed an important difference in grain size with well-defined larger grains of size 1–2 μm in the PVD films as compared to CSP layers (600 nm). Another important characteristic that differentiates the two precursor films is the oxygen contamination. X-ray photoelectron spectroscopy showed the presence of oxygen in CSP films. The oxygen atoms could be bonded to indium by replacing Se vacancies, which are formed during CSP deposition. Taking account of the obtained results, such CSP films can be used as precursor layer in a PVD process in order to produce CISe absorber films. - Highlights: • To find the intricacies involved in spray pyrolysis (CSP) and physical vapor (PVD) deposition. • Comparison of CSP and PVD film formations — especially in structural properties. • Feasibility to substitute CSP (cheaper) films for PVD in the manufacturing process. • Decreasing the global production cost of Cu(In,Ga)Se{sub 2} devices in the 3-stage process.

  7. Biomass valorisation by staged degasification A new pyrolysis-based thermochemical conversion option to produce value-added chemicals from lignocellulosic biomass

    NARCIS (Netherlands)

    de Wild, P. J.; den Uil, H.; Reith, J. H.; Kiel, J. H. A.; Heeres, H. J.

    2009-01-01

    Pyrolysis of lignocellulosic biomass leads to an array Of useful solid, liquid and gaseous products. Staged degasification is a pyrolysis-based conversion route to generate value-added chemicals from biomass. Because of different thermal stabilities of the main biomass constituents hemicellulose. ce

  8. Chemical and mineralogical evaluation of slag products derived from the pyrolysis/melting treatment of MSW.

    Science.gov (United States)

    Saffarzadeh, Amirhomayoun; Shimaoka, Takayuki; Motomura, Yoshinobu; Watanabe, Koichiro

    2006-01-01

    This paper provides the results of studies on the characteristics of novel material derived from pyrolysis/melting treatment of municipal solid waste in Japan. Slag products from pyrolysis/melting plants were sampled for the purpose of detailed phase analysis and characterization of heavy metal-containing phases using optical microscopy, electron probe microanalysis (EPMA), XRF and XRD. The study revealed that the slag material contains glass (over 95%), oxide and silicate minerals (spinel, melilite, pseudowollastonite), as well as individual metallic inclusions as the major constituents. A distinct chemical diversity was discovered in the interstitial glass in terms of silica content defined as low and high silica glass end members. Elevated concentrations of Zn, Cr, Cu, Pb and Ba were recorded in the bulk composition. Cu, Pb and Ba behave as incompatible elements since they have been markedly characterized as part of polymetallic alloys and insignificantly sulfides in the form of spherical metallic inclusions associated with tracer amounts of other elements such as Sb, Sn, Ni, Zn, Al, P and Si. In contrast, an appreciable amount of Zn is retained by zinc-rich end members of spinel and partially by melilite and silica glass. Chromium exhibits similar behavior, and is considerably held by Cr-rich spinel. The intense incorporation of Zn and Cr into spinel indicates the very effective enrichment of these two elements into phases more environmentally resistant than glass. There was no evidence, however, that Cu and Pb enter into the structure of the crystalline silicates or oxides that may lead to their easier leachability upon exposure to the environment. PMID:16446083

  9. Main routes for the thermo-conversion of biomass into fuels and chemicals. Part 1: Pyrolysis systems

    International Nuclear Information System (INIS)

    Since the energy crises of the 1970s, many countries have become interest in biomass as a fuel source to expand the development of domestic and renewable energy sources and reduce the environmental impacts of energy production. Biomass is used to meet a variety of energy needs, including generating electricity, heating homes, fueling vehicles and providing process heat for industrial facilities. The methods available for energy production from biomass can be divided into two main categories: thermo-chemical and biological conversion routes. There are several thermo-chemical routes for biomass-based energy production, such as direct combustion, liquefaction, pyrolysis, supercritical water extraction, gasification, air-steam gasification and so on. The pyrolysis is thermal degradation of biomass by heat in the absence of oxygen, which results in the production of charcoal (solid), bio-oil (liquid), and fuel gas products. Pyrolysis liquid is referred to in the literature by terms such as pyrolysis oil, bio-oil, bio-crude oil, bio-fuel oil, wood liquid, wood oil, liquid smoke, wood distillates, pyroligneous tar, and pyroligneous acid. Bio-oil can be used as a fuel in boilers, diesel engines or gas turbines for heat and electricity generation.

  10. Mass production of chemicals from biomass-derived oil by directly atmospheric distillation coupled with co-pyrolysis

    Science.gov (United States)

    Zhang, Xue-Song; Yang, Guang-Xi; Jiang, Hong; Liu, Wu-Jun; Ding, Hong-Sheng

    2013-01-01

    Production of renewable commodity chemicals from bio-oil derived from fast pyrolysis of biomass has received considerable interests, but hindered by the presence of innumerable components in bio-oil. In present work, we proposed and experimentally demonstrated an innovative approach combining atmospheric distillation of bio-oil with co-pyrolysis for mass production of renewable chemicals from biomass, in which no waste was produced. It was estimated that 51.86 wt.% of distillate just containing dozens of separable organic components could be recovered using this approach. Ten protogenetic and three epigenetic compounds in distillate were qualitatively identified by gas chromatography/mass spectrometry and quantified by gas chromatography. Among them, the recovery efficiencies of acetic acid, propanoic acid, and furfural were all higher than 80 wt.%. Formation pathways of the distillate components in this process were explored. This work opens up a fascinating prospect for mass production of chemical feedstock from waste biomass.

  11. CuS p- type thin film characterization deposited on Ti, ITO and glass substrates using spray pyrolysis deposition (SPD) for light emitting diode (LED) application

    Science.gov (United States)

    Sabah, Fayroz A.; Ahmed, Naser M.; Hassan, Z.; Rasheed, Hiba S.; Azzez, Shrook A.; Al-Hazim, Nabeel Z.

    2016-07-01

    The copper sulphide (CuS) thin films were grown with good adhesion by spray pyrolysis deposition (SPD) on Ti, ITO and glass substrates at 200 °C. The distance between nozzle and substrate is 30 cm. The composition was prepared by mixing copper chloride CuCl2.2H2O as a source of Cu2+ and sodium thiosulfate Na2S2O3.5H2O as a source of and S2-. Two concentrations (0.2 and 0.4 M) were used for each CuCl2 and Na2S2O3 to be prepared and then sprayed (20 ml). The process was started by spraying the solution for 3 seconds and after 10 seconds the cycle was repeated until the solution was sprayed completely on the hot substrates. The structural characteristics were studied using X-ray diffraction; they showed covellite CuS hexagonal crystal structure for 0.2 M concentration, and covellite CuS hexagonal crystal structure with two small peaks of chalcocite Cu2S hexagonal crystal structure for 0.4 M concentration. Also the surface and electrical characteristics were investigated using Field Emission Scanning Electron Microscopy (FESEM) and current source device, respectively. The surface study for the CuS thin films showed nanorods to be established for 0.2 M concentration and mix of nanorods and nanoplates for 0.4 M concentration. The electrical study showed ohmic behavior and low resistivity for these films. Hall Effect was measured for these thin films, it showed that all samples of CuS are p- type thin films and ensured that the resistivity for thin films of 0.2 M concentration was lower than that of 0.4 M concentration; and for the two concentrations CuS thin film deposited on ITO had the lowest resistivity. This leads to the result that the conductivity was high for CuS thin film deposited on ITO substrate, and the conductivity of the three thin films of 0.2 M concentration was higher than that of 0.4 M concentration.

  12. The Spray-Rite Kit. A Guide to Using Chemicals on the Farm.

    Science.gov (United States)

    Stevens, Nick; And Others

    This resource is designed to assist rural adult literacy students. It deals with chemicals on the farm and aims to help students understand the technical language, concepts, and operations associated with spraying safely and effectively. The kit proceeds step-by-step from purchase to disposal. Material is divided into two sections. Section 1…

  13. Photoelectrochemical performances of indium-doped CdS0.2Se0.8 thin film electrodes prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted Highlights: → Polycrystalline undoped and indium doped CdS0.2Se0.8 thin films were deposited on FTO coated glass substrates by spray pyrolysis. → The films are studied for various photoelectrochemical performance parameters. → The study reveals that the films exhibit n-type conductivity. → Efficiency and fill factor of PEC cell are found to be improve from 0.79% and 0.46 to 2.12% and 0.49, respectively, with indium doping in CdS0.2Se0.8 thin films. → Electrochemical impedance spectroscopy study shows that doping of indium in CdS0.2Se0.8 thin film improves the performance of PEC cell. - Abstract: Polycrystalline undoped and indium-doped CdS0.2Se0.8 thin films were deposited on FTO-coated glass substrates by spray pyrolysis. The cell configurations CdS0.2Se0.8/1 M (Na2S + S + NaOH)/C and In:CdS0.2Se0.8/1 M (Na2S + S + NaOH)/C were used to study a wide range of photoelectrochemical characteristics including capacitance-voltage in the dark, current-voltage characteristics in the dark and under illumination, photovoltaic power output and spectral response and to perform electrochemical impedance spectroscopy studies. The study reveals that the films exhibit n-type conductivity. Various PEC parameters such as the junction ideality factor under illumination, series and shunt resistances, fill factor and efficiency have been estimated for the PEC cells formed with CdS0.2Se0.8 and indium-doped CdS0.2Se0.8 thin films. The efficiency and fill factor of these PEC cells are found to be improved from 0.79% and 0.46 to 2.12% and 0.49, respectively, with indium doping in CdS0.2Se0.8 thin films. Electrochemical impedance spectroscopy studies show that doping of indium into CdS0.2Se0.8 thin film improves the performance of resulting PEC cells.

  14. Synthesis of composite WO{sub 3}/TiO{sub 2} nanoparticles by flame-assisted spray pyrolysis and their photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Arutanti, Osi [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima 739-8527 (Japan); Nandiyanto, Asep Bayu Dani [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima 739-8527 (Japan); Departemen Kimia, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudhi No. 229, Bandung 40154 (Indonesia); Ogi, Takashi, E-mail: ogit@hiroshima-u.ac.jp [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima 739-8527 (Japan); Iskandar, Ferry [Department of Physics, Institut Teknologi Bandung, Jl. Ganesha No. 10, Bandung 40132 (Indonesia); Kim, Tae Oh [Department of Environmental Engineering, Kumoh National Institute of Technology, Daehak-ro 61, Gumi, Gyeongbuk 730-701 (Korea, Republic of); Okuyama, Kikuo [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima 739-8527 (Japan)

    2014-04-05

    Highlights: • We synthesize composite WO{sub 3}/TiO{sub 2} nanoparticles using spray pyrolysis method. • We varied the concentration of AMT and TTIP in wide range ratio (0–100 wt%). • Photodegradation drastically improvement when the ratio of AMT below than 25 wt%. • When the ratio of AMT of above 25 wt%, the photodegradation slightly improvement. • The changes of photodegradation rate are influenced by band gap energy and surface area. -- Abstracts: Combining of tungsten trioxide (WO{sub 3}) with titanium dioxide (TiO{sub 2}) have been an interesting research subject because different from conventional TiO{sub 2} material, this composite can be used and activated under visible-light irradiation and has better photocatalytic efficiency. The purpose of this study was to synthesize composite WO{sub 3}/TiO{sub 2} nanoparticles and to investigate the detail effect of composition of ammonium metatungstate (AMT, as a WO{sub 3} source) and titanium isopropoxide (TTIP, as a TiO{sub 2} source) in the wide range composition ratio on particle morphology (i.e.,outer size (from 20 to 90 nm), shape, and structure), crystallinity, and photocatalytic performance. To synthesize composite WO{sub 3}/TiO{sub 2} nanoparticles, a flame-assisted spray-pyrolysis method was used. Experimental results showed that the amount of AMT (from 0 to 25 wt%) had shown a significant impact on the photocatalytic performance, however deviation of this amount had improve catalyst performance slightly. The change of photocatalytic activity is mainly influenced by band gap energy and surface area. To confirm the fundamental reason for this catalytic improvement, the effect of WO{sub 3} and TiO{sub 2} amounts on surface area, light absorbance, and charge separation analysis was investigated. The experimental results were also completed along with the proposal photocatalytic mechanism of particles containing WO{sub 3} and TiO{sub 2}. In addition, although our present photocatalytic activity

  15. Pyrolysis temperature affects phosphorus transformation in biochar: Chemical fractionation and (31)P NMR analysis.

    Science.gov (United States)

    Xu, Gang; Zhang, You; Shao, Hongbo; Sun, Junna

    2016-11-01

    Phosphorus (P) recycling or reuse by pyrolyzing crop residue has recently elicited increased research interest. However, the effects of feedstock and pyrolysis conditions on P species have not been fully understood. Such knowledge is important in identifying the agronomic and environmental uses of biochar. Residues of three main Chinese agricultural crops and the biochars (produced at 300°C-600°C) derived from these crops were used to determine P transformations during pyrolysis. Hedley sequential fractionation and (31)P NMR analyses were used in the investigation. Our results showed that P transformation in biochar was significantly affected by pyrolysis temperature regardless of feedstock (Wheat straw, maize straw and peanut husk). Pyrolysis treatment transformed water soluble P into a labile (NaHCO3-Pi) or semi-labile pool (NaOH-Pi) and into a stable pool (Dil. HCl P and residual-P). At the same time, organic P was transformed into inorganic P fractions which was identified by the rapid decomposition of organic P detected with solution (31)P NMR. The P transformation during pyrolysis process suggested more stable P was formed at a higher pyrolysis temperature. This result was also evidenced by the presence of less soluble or stable P species, such as such as poly-P, crandallite (CaAl3(OH)5(PO4)2) and Wavellite (Al3(OH)3(PO4)2·5H2O), as detected by solid-state (31)P NMR in biochars formed at a higher pyrolysis temperature. Furthermore, a significant proportion of less soluble pyrophosphate was identified by solution (2%-35%) and solid-state (8%-53%) (31)P NMR, which was also responsible for the stable P forms at higher pyrolysis temperature although their solubility or stability requires further investigation. Results suggested that a relatively lower pyrolysis temperature retains P availability regardless of feedstock during pyrolysis process. PMID:27343937

  16. Change of physical and chemical properties of the solid phase during biomass pyrolysis; Aenderung der physikalisch-chemischen Eigenschaften des Feststoffs waehrend der Biomassepyrolyse

    Energy Technology Data Exchange (ETDEWEB)

    Klose, Wolfgang [Kassel Univ. (Germany). Inst. fuer Thermische Energietechnik; Rincon, Sonia; Gomez, Alexander [Universidad Nacional de Colombia, Bogota (Colombia). Dept. de Ingenieria Mecanica y Mecatronica

    2009-01-15

    The effects of the final pyrolysis temperature on the development of the chemical composition and on the porosity of biomass undergoing pyrolysis are investigated through experiments in a thermobalance at laboratory scale of grams. Changes in the grain size of individual particles of biomass during pyrolysis are also investigated as a function of temperature in a microscope equipped with heating and camera. Oil palm shells are selected as raw materials due to their availability as biomass residue and their physical and chemical characteristics. These experiments are important for reactor design purposes in the field of thermochemical conversion, offering important information for the mathematical modelling of the processes. (orig.)

  17. Effect of tin doping on the optical properties of indium oxide films by a spray pyrolysis method

    International Nuclear Information System (INIS)

    Thin films of stannum doped indium oxide were deposited on glass by a X-ray pyrolysis method. The substrate temperature and the rate of flow of the carrier gas were fixed at 4500C and 2.5 litre/minute respectively during deposition. The dependence of the optical properties of the films on the doping concentration was studied. It is found that the transmission of the visible wavelengths (300 to 800 nm) through the films increases around 5% from 74.9% as the film was doped with 10% stannum. It is also found that the optical energy bandgap increases 0.2 eV from 3.16 to 3.36 eV by doping the film with 10% stannum. The increase is attributed to the Bernstein-Moss (1) and self-energy (2) effects

  18. An easy and innovative method based on spray-pyrolysis deposition to obtain high efficiency cathodes for Solid Oxide Fuel Cells

    Science.gov (United States)

    dos Santos-Gómez, L.; Porras-Vázquez, J. M.; Martín, F.; Ramos-Barrado, J. R.; Losilla, E. R.; Marrero-López, D.

    2016-07-01

    A novel electrode preparation method based on the spray-pyrolysis deposition of metal nitrate solutions onto a porous electrolyte scaffold is proposed. This method has been proved with different cathode materials, usually used in Solid Oxide Fuel Cells, such as La0.8Sr0.2MnO3-δ and La0.6Sr0.4Co1-xFexO3-δ (x = 0, 0.2, 0.8 and 1). The electrode microstructure is composed by two layers; the inner layer is a porous electrolyte scaffold homogeneously coated by cathode nanoparticles, providing an increased number of triple phase boundary sites for oxygen reduction, whereas, the top layer is formed by only cathode nanoparticles and acts mainly as a current collector. Polarization resistance values as low as 0.07 and 1.0 Ω cm2 at 600 and 450 °C, respectively, are obtained at open circuit voltage. This alternative approach has several advantages with respect to the traditional wet infiltration method for large area electrode fabrication, such as higher reproducibility, shorter preparation time in a single thermal deposition step, and easy implementation at industrial scale as a continuous process.

  19. Preparation and characterization of Cu2SnS3 ternary semiconductor nanostructures via the spray pyrolysis technique for photovoltaic applications

    International Nuclear Information System (INIS)

    Thin films of Cu2SnS3 have been deposited by the spray pyrolysis technique. Various Sn/Cu molar ratios (from 0.0 to 1.0) were applied, which allowed the study of the copper tin sulfide phase. Structural, morphological and compositional analyses have been carried out using x-ray diffraction, field emission scanning electron microscopy and energy dispersive spectroscopy. The pure CuS thin film showed the covellite phase with hexagonal crystal structure, and with increasing the Sn/Cu molar ratio, the films grown were crystallized with triclinic Cu2SnS3 ternary phase. Optical measurement analysis showed that the deposited layers have a relatively high absorption coefficient (∼105 cm-1) in the visible spectrum, about one order of magnitude higher than in other published reports. Also these layers presented a reduction of about 1 eV in the values of band gap from 2.57 to 1.58 eV with an increment in the Sn/Cu molar ratio from 0.0 to 1.0. The electrical properties studies showed that all these samples are p-type semiconductors and the resistivity decreases with increasing the Sn/Cu molar ratio.

  20. An investigation on substrate temperature and copper to sulphur molar ratios on optical and electrical properties of nanostructural CuS thin films prepared by spray pyrolysis method

    International Nuclear Information System (INIS)

    Copper sulphide (CuS) thin films have been deposited on glass substrates by spray pyrolysis method using an aqueous solutions of copper (II) acetate and thiourea with different Cu to S molar ratios (0.33 and 0.43) at various substrate temperatures of 260, 285 and 310 °C. The structural, optical and electrical characterizations have been carried out using XRD, UV-Vis. transmittance/reflectance, PL spectra and Hall effect measurements. These characterizations indicated the formation of a CuS single phase (covellite) with polycrystalline nature with preferred orientation along (1 0 2) plane, except one with amorphous nature. Optical studies showed that the deposited layers have a relatively high absorption coefficient (5 × 104 to 1 × 105 cm-1) in the visible range, with an effective optical band gap of ∼2.4-2.6 eV. The Hall effect data showed that all the grown samples have a degenerate p-type conductivity with a hole concentration of ∼1.8 × 1020 to 1.7 × 1021 cm-3.

  1. Production and characterization of submicron hematite (α−Fe{sub 2}O{sub 3}) particles by ultrasonic spray pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Kırcı, Burak; Ebin, Burçak; Gürmen, Sebahattin [Department of Metallurgical and Materials Engineering, Istanbul Technical University Istanbul (Turkey)

    2013-12-16

    The ultrasonic spray pyrolysis (USP) method has been used to prepare submicron hematite (α−Fe{sub 2}O{sub 3}) particles using two different industrial pickling solutions of iron chloride (41 g/L FeCl{sub 2} and 54 g/L FeCl{sub 3}) Particles were obtained by thermal decomposition of generated aerosols from precursor solutions using 1.7 MHz ultrasonic atomizer. Reaction temperature was set up at 800 °C and aerosol droplets were carried into the heated zone by 0.7 L/min air flow rate. X-Ray Diffraction (XRD) studies were used to determine the crystal structure and crystallite size of the particles. Results indicate that patterns correspond to hematite phase with rhombohedral crystal structure (space group: R3c). The crystallite sizes of particles prepared from FeCl{sub 2} and FeCl{sub 3} solutions that were calculated from Scherrer equation are 59 and 33 nm, respectively. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) investigations give detailed information about particle size, morphology and composition. SEM micrographs show that hematite nanoparticles aggregate and formed spherical secondary particles in submicron range.

  2. Structural and optical properties of ZnO nanostructures grown by aerosol spray pyrolysis: Candidates for room temperature methane and hydrogen gas sensing

    Energy Technology Data Exchange (ETDEWEB)

    Motaung, D.E., E-mail: dmotaung@csir.co.za [DST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P. O. Box 395, Pretoria 0001 (South Africa); Mhlongo, G.H., E-mail: gmhlongo@csir.co.za [DST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P. O. Box 395, Pretoria 0001 (South Africa); Kortidis, I. [Transparent Conductive Materials Lab, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, 100N. Plastira str., Vassilika Vouton, 70013 Heraklion, Crete (Greece); Nkosi, S.S., E-mail: skosi@csir.co.za [CSIR-National Laser Centre, 626 Meiring Naude Rd, Brummeria, Pretoria 0001 (South Africa); School of Physics, University of Witwatersrand, Private Bag X3, Johannesburg 2030 (South Africa); Malgas, G.F.; Mwakikunga, B.W.; Ray, S.Sinha [DST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P. O. Box 395, Pretoria 0001 (South Africa); Kiriakidis, G., E-mail: kiriakid@iesl.forth.gr [Transparent Conductive Materials Lab, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, 100N. Plastira str., Vassilika Vouton, 70013 Heraklion, Crete (Greece); University of Crete, Department of Physics, 710 03 Heraklion, Crete (Greece)

    2013-08-15

    We report on the synthesis of ZnO films by aerosol spray pyrolysis method at different deposition times. The surface morphology, crystal structure and the cross-sectional analysis of the prepared ZnO films were characterized by X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HR-TEM). XRD analysis revealed that the ZnO films are polycrystalline in nature. Structural analysis exploiting cross-sectional TEM profile showed that the films composed of nano-particles and columnar structures growing perpendicular to the substrate. AFM revealed that the columnar structures have a higher surface roughness as compared to the nanoparticles. The effect of ZnO crystallite size and crystallinity on the gas sensing performance of hydrogen and methane gases was also evaluated. Sensing film based on ZnO nanoparticles has numerous advantages in terms of its reliability and high sensitivity. These sensing materials revealed an improved response to methane and hydrogen gases at room temperature due to their high surface area, indicating their possible application as a gas sensor.

  3. Structural and optical properties of ZnO nanostructures grown by aerosol spray pyrolysis: Candidates for room temperature methane and hydrogen gas sensing

    Science.gov (United States)

    Motaung, D. E.; Mhlongo, G. H.; Kortidis, I.; Nkosi, S. S.; Malgas, G. F.; Mwakikunga, B. W.; Ray, S. Sinha; Kiriakidis, G.

    2013-08-01

    We report on the synthesis of ZnO films by aerosol spray pyrolysis method at different deposition times. The surface morphology, crystal structure and the cross-sectional analysis of the prepared ZnO films were characterized by X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HR-TEM). XRD analysis revealed that the ZnO films are polycrystalline in nature. Structural analysis exploiting cross-sectional TEM profile showed that the films composed of nano-particles and columnar structures growing perpendicular to the substrate. AFM revealed that the columnar structures have a higher surface roughness as compared to the nanoparticles. The effect of ZnO crystallite size and crystallinity on the gas sensing performance of hydrogen and methane gases was also evaluated. Sensing film based on ZnO nanoparticles has numerous advantages in terms of its reliability and high sensitivity. These sensing materials revealed an improved response to methane and hydrogen gases at room temperature due to their high surface area, indicating their possible application as a gas sensor.

  4. Orientation-dependent low field magnetic anomalies and room-temperature spintronic material – Mn doped ZnO films by aerosol spray pyrolysis

    International Nuclear Information System (INIS)

    Graphical abstract: Optical microscopy images of Mn doped ZnO films deposited for 20 min. Highlights: •Mn–ZnO films showing transparent spherical bubbles were synthesized by ASP. •LFMA phenomenon was observed for these films. •A relatively novel reversal magnetic feature to that of LFMA was observed. •Ferromagnetic to paramagnetic transition due to Mn doping was observed. •Angular dependence analysis showed evidence of magnetic anisotropy present. -- Abstract: High quality un-doped and Mn-doped ZnO films deposited by a simple aerosol spray pyrolysis technique for 20 and 30 min were studied using electron paramagnetic resonance (EPR), X-ray diffraction (XRD) and atomic force microscopy (AFM) techniques. EPR analysis showed novel observation of low field microwave absorption (LFMA) on the manganese (Mn) doped zinc oxide (ZnO) films at various Mn concentrations. The results showed a peculiar behavior, reversal signal to that of LFMA. These findings also demonstrated that these films contain ferromagnetism at room temperature with possible applications in spintronics. Angular dependence measurements were found to induce magnetic transition from ferromagnetism to paramagnetism. Structural analysis showed that the undertaken materials are in wurtzite structures. The light absorption edge of Mn–ZnO films red shifted which enhanced the observed ferromagnetism. The direct modulation of the band gap caused by Mn–ZnO substitution is responsible for the red shift effect in absorption edge of ZnO

  5. Synthesis of nano-crystalline spherical cobalt-iron (Co-Fe) alloy particles by ultrasonic spray pyrolysis and hydrogen reduction

    International Nuclear Information System (INIS)

    Spherical nano-crystalline Co-Fe particles were produced by ultrasonic spray pyrolysis (USP) of aqueous solutions of cobalt-iron chloride followed by thermal decomposition of generated aerosols in hydrogen atmosphere. The effect of the precursor solution in the range of 0.05 M, 0.1 M, 0.2 M and 0.4 M on the morphology and crystallite size of the Co-Fe alloy particles are investigated under the conditions of 1.5 h running time, 800 deg. C reduction temperature, and 1.0 l/min H2 volumetric flow rate. X-ray diffraction (XRD) studies and Scherer crystallite size calculations show that the crystallite size varies between 25 nm and 27 nm. Scanning electron microscopy (SEM) observations reveal that the the precursor solution strongly influences the particle size of the synthesized Co-Fe alloy particles. Energy dispersive spectroscopy (EDS) results indicate that particles consist of iron and cobalt. Spherical nano-crystalline Co-Fe alloy particles in the range of 100-920 nm were obtained at 800 deg. C.

  6. Structural and optical properties of ZnO nanostructures grown by aerosol spray pyrolysis: Candidates for room temperature methane and hydrogen gas sensing

    International Nuclear Information System (INIS)

    We report on the synthesis of ZnO films by aerosol spray pyrolysis method at different deposition times. The surface morphology, crystal structure and the cross-sectional analysis of the prepared ZnO films were characterized by X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HR-TEM). XRD analysis revealed that the ZnO films are polycrystalline in nature. Structural analysis exploiting cross-sectional TEM profile showed that the films composed of nano-particles and columnar structures growing perpendicular to the substrate. AFM revealed that the columnar structures have a higher surface roughness as compared to the nanoparticles. The effect of ZnO crystallite size and crystallinity on the gas sensing performance of hydrogen and methane gases was also evaluated. Sensing film based on ZnO nanoparticles has numerous advantages in terms of its reliability and high sensitivity. These sensing materials revealed an improved response to methane and hydrogen gases at room temperature due to their high surface area, indicating their possible application as a gas sensor.

  7. Influence of substrate temperature on physical properties of (111 oriented CdIn2S4 thin films by nebulized spray pyrolysis technique

    Directory of Open Access Journals (Sweden)

    J.Raj Mohamed

    2016-06-01

    Full Text Available In this work, we present the substrate temperature influenced change in the structural, optical, morphological, and electrical conductivity properties of CdIn2S4 thin films deposited on amorphous glass substrates by nebulized spray pyrolysis (NSP technique. X-ray diffraction pattern revealed that the as-deposited CdIn2S4 thin films had a cubic structure with a preferred orientation along (111 plane. The reduced strain by increasing the substrate temperature from 200 to 350 °C increased the average crystalline size from 17 to 33 nm while the formation of secondary phases such as CdIn2O4 and In2O3 reduced it to 21 nm after the substrate temperature at 450 °C. The energy dispersive analysis by X-ray (EDAX studies confirmed the presence of Cd, In, and S. The absorption coefficient, direct band gap energy, Urbach energy, skin depth, and extinction coefficient of CdIn2S4 films were analyzed by optical absorption spectra. The better conductivity and mobility noticed at Ts = 350 °C are explained by carrier concentration and crystalline size. Better optical and electrical conductivity behavior of CdIn2S4 thin film sample suggests for effective PEC solar cell fabrication.

  8. Peculiarities in electrical and optical properties of Cu2Zn1- x Mn x SnS4 films obtained by spray pyrolysis

    Science.gov (United States)

    Orletskii, I. G.; Mar'yanchuk, P. D.; Solovan, M. N.; Maistruk, E. V.; Kozyarskii, D. P.

    2016-03-01

    Thin films of Cu2Zn1- x Mn x SnS4 (0 ≤ x ≤ 1) solid solutions have been obtained for the first time by the spray pyrolysis of aqueous salt solutions (copper, zinc, manganese, and tin chlorides and thiourea) at a temperature of T S = 563 K. The films possess specific electric conductivities within σ ≈ 35-422 Ω-1 cm-1 and optical bandgap width E g op that increases with the manganese content from 1.54 eV ( x = 0) to 2.25 eV ( x = 1). Electrical and optical properties of the obtained films have been studied and analyzed based on a model of polycrystalline materials with grain boundaries. The energy barriers Eb between grains have been determined. The dependence of the bandgap of Cu2Zn1- x Mn x SnS4 (0 ≤ x ≤ 1) solid solutions on the composition has been established using the results of measurements of the optical transmission and absorption coefficients.

  9. Thickness dependent optical properties of PEMA and (PEMA)0.85/(ZnO)0.15 nanocomposite films deposited by spray pyrolysis technique on ITO substrate

    Science.gov (United States)

    Thakur, Anjna; Thakur, Priya; Yadav, Kamlesh

    2016-05-01

    In this paper, poly (ethyl methacrylate) (PEMA) and (PEMA)0.85/(ZnO)0.15 nanocomposite films for 2, 3, 4 and 5 minutes have been deposited by spray pyrolysis technique on indium tin oxide (ITO) coated substrate. The effect of thickness of the film on the morphological and optical properties of PEMA and (PEMA)0.85/(ZnO)0.15 nanocomposite films are studied. The morphological and optical properties of pure PEMA and (PEMA)0.85/(ZnO)0.15 nanocomposite films are compared. The field emission scanning electron microscopy (FESEM) shows that as the thickness of film increases, uniformity of films increases. It is found from UV-Visible spectra that the energy band gap decreases with increasing the deposition time and refractive index increases with increasing the thickness of the film. The band gap of the nanocomposites is found less than the pure polymer film and opposite trend is observed for refractive index. The optical absorption of PEMA/ZnO nanocomposite films is higher than pure PEMA film. The thickness of the nanocomposite film plays a significant role in the tunability of the optical properties.

  10. Effect of Sn doping on the structural, optical and electrical properties of TiO2 films prepared by spray pyrolysis

    Science.gov (United States)

    Arunachalam, A.; Dhanapandian, S.; Manoharan, C.

    2016-02-01

    In this work, highly oriented pure and Tin-doped Titanium dioxide (Sn-doped TiO2) with porous nature photoelectrodes were deposited on ITO glass plates using spray pyrolysis technique. The XRD pattern revealed the formation of anatase TiO2 with the maximum intensity of (101) plane while doping 6 at% of Sn. The morphological studies depicted the porous nature with the uniform arrangement of small-sized grains. The presence of tin confirmed with the EDX spectra. The size of particles of 13 nm was observed from High Resolution Transmission Electron Microscopy (HR-TEM) analysis. The average transmittance was about 85% for the doped photoelectrode and was observed for the photoelectrode deposited with 6 at% of tin, with decreased energy band gap. The PL study showed the emission peak at 391 nm. The maximum carrier concentration and Hall mobility was observed for the photoelectrode deposited with 6 at% of tin. With these studies, the DSSCs were prepared separately with the dye extracted from Hibiscus Rosasinesis and Hibiscus Surttasinesis and their efficiency was maximum for the DSSC prepared with 6 at% of tin.

  11. Structural and magnetic characterization of LiMn1.825Cr0.175O4 spinel obtained by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Quaternary spinel oxide LiMn1.825Cr0.175O4 powder was synthesized by using an ultrasonic spray pyrolysis method, without additional annealing. The crystal structure of the as-prepared powder was revealed by X-ray powder diffraction and identified as a single spinel phase with Fd3m space group. The powders had a spherical morphology with extremely smooth surface appearance and densely congested interior structure. Transmission electron microscopy confirmed that the particle consisted by the cohesion of the primary particles. Magnetic measurements performed in DC field in both zero-field-cooled and field-cooled regimes, as well as AC susceptibility experiments, show that system undergoes spin-glass transition at the freezing temperature T f = 20 K. The value of the effective magnetic moment μ eff = 4.34 μ B obtained from the Curie-Weiss fit in the high temperature region confirms the substitution of Mn3+ ions with Cr3+ ions

  12. (Cu, Fe, Co, or Ni)-doped tin dioxide films deposited by spray pyrolysis: Doping influence on thermal stability of the film structure

    International Nuclear Information System (INIS)

    The results of doping influence on thermal stability of the SnO2 film morphology are presented in this article. The SnO2 films doped by Fe, Cu, Ni, Co (16 at.%) were deposited by spray pyrolysis from 0.2 M SnCl4-water solution at Tpyr 350-450 deg. C. The annealing at 850-1030 deg. C was carried out in the atmosphere of the air. The change of such parameters as film morphology, the grain size, texture and the intensity of X-ray diffraction (XRD) peaks have been controlled. For structural analysis of tested films we have been using X-ray diffraction, Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM) techniques. It was established that the doping does not improve thermal stability of both film morphology and the grain size. It was made a conclusion that the increased contents of the fine dispersion phase of tin oxide in the doped metal oxide films, and the coalescence of this phase during thermal treatment are the main factors, responsible for observed changes in the morphology of the doped SnO2 films

  13. High resolution electron microscopy studies of nickel oxide thin films deposited on ITO substrates prepared by spray pyrolysis and magnetron sputtering

    International Nuclear Information System (INIS)

    Nickel thin films were produced by DC sputtering on ITO substrates deposited in turn over glass substrates. The ITO films were prepared by spray pyrolysis and DC magnetron sputtering deposition methods respectively. The glass-ITO-Nickel Oxide sandwich samples were studied by X ray diffraction. Also scanning and transmission electron microscopy were used to determine morphological and structural properties of nickel oxides films at different stages of electrochemical treatments. Several nickel oxide species were generated under electrochemical treatments and were decisive in the generation of the electrochromic properties of our materials. The optical behavior of our films, related with electrochromic properties were studied by spectrophotometric techniques. Electron microscopy techniques were used to detect morphological and structural variations. High resolution electron microscopy, (HREM) and associated computational techniques were used to determine and study at nanometer level the structure and composition of the species generated at each stage of electrochemical attack. After cyclic voltammetry treatments, numerous structural defects were detected by HREM in the surface small grains; the role of these defects in electrochromic effects are discussed in this work. (Authors)

  14. Characteristics of Al-doped ZnO thin films obtained by ultrasonic spray pyrolysis: effects of Al doping and an annealing treatment

    International Nuclear Information System (INIS)

    Transparent conducting Al-doped ZnO thin films were prepared on silica glass substrates by an ultrasonic spray pyrolysis method. The effects of Al doping and an annealing treatment on electrical and optical properties of ZnO thin films were investigated. Zinc acetate dihydrate, 2-methoxyethanol and aluminum chloride were used as a starting material, a solvent and a dopant source, respectively. The electrical conductivity of ZnO films was improved by Al doping and by annealing in a reducing atmosphere. The minimum electrical resistivity was obtained in the 3 at.% Al-doped film annealed at 500 deg. C in nitrogen with 5% hydrogen and its value was 1.71x10-2 Ω cm. The average optical transmittance of all films, regardless of a doping concentration and an annealing condition, was higher than 80% in the visible range. The optical direct band gap of films was dependent on the amount of a dopant and the annealing treatment in a reducing atmosphere. The optical direct band gap value of 3 at.% Al-doped films annealed at 500 deg. C in nitrogen were 3.33 eV

  15. Effect of variation of precursor concentration on structural, microstructural, optical and gas sensing properties of nanocrystalline TiO2 thin films prepared by spray pyrolysis techniques

    Indian Academy of Sciences (India)

    Lalchand A Patil; Dinesh N Suryawanshi; Idris G Pathan; Dhanashri G Patil

    2013-12-01

    The objective of the present paper is to investigate the effect of variation of precursor concentration (0.01, 0.02 and 0.03 M) on the structural, microstructural, optical and gas sensing properties of TiO2 thin films. Titanium dioxide (TiO2) films were prepared from aqueous solution of titanium chloride (TiCl3.6H2O, 99.9%pure, Merckmade, Germany) onto the glass substrates heated at a temperature of 350 °C by the spray pyrolysis technique. Bandgap energy of the films vary from 3.28 to 3.29 eV. X-ray diffraction shows that films to be nanocrystalline with anatase phase having tetragonal crystal structure. The values calculated from electron diffraction patterns (TEM) were observed to be matching with values calculated from XRD. Transmission electron microscopy (TEM) reveled that grain sizes were observed to increase (10–29 nm) with an increase in the concentration of precursor solution. The gas sensing performance of the films was tested.

  16. A Review on the Preparation of Borazine-derived Boron Nitride Nanoparticles and Nanopolyhedrons by Spray-pyrolysis and Annealing Process

    Directory of Open Access Journals (Sweden)

    Vincent Salles

    2016-01-01

    Full Text Available Boron nitride (BN nanostructures (= nanoBN are struc‐ tural analogues of carbon nanostructures but display different materials chemistry and physics, leading to a wide variety of structural, thermal, electronic, and optical applications. Proper synthesis routes and advanced structural design are among the great challenges for preparing nanoBN with such properties. This review provides an insight into the preparation and characteriza‐ tion of zero dimensional (0D nanoBN including nanopar‐ ticles and nanopolyhedrons from borazine, an economically competitive and attractive (from a technical point of view molecule, beginning with a concise intro‐ duction to hexagonal BN, followed by an overview on the past and current state of research on nanoparticles. Thus, a review of the spray-pyrolysis of borazine to form BN nanoparticles is firstly presented. The use of BN nanopar‐ ticles as precursors of BN nanopolyhedrons is then de‐ tailed. Applications and research perspectives for these 0D nanoBN are discussed in the conclusion.

  17. Investigations on the crystalline, topographic, electrical and optical characteristics of doubly doped (Si + F) SnO2 films deposited using spray pyrolysis technique

    Science.gov (United States)

    Turgut, G.; Thirumurugan, K.; Ravichandran, K.

    2015-10-01

    Silicon and fluorine (Si + F) co-doped SnO2 thin films were deposited on soda lime glass substrate using the spray pyrolysis technique. The Si and F doping levels were varied from 0-10 and 2.5-10 in steps of 2.5 at. %, respectively. Initially the optimum doping level of Si is found (7.5 at. %) at which the film exhibits the minimum electrical resistivity value (4.23 × 10-3 Ω cm) and then the doping level of F is varied and it is found to be better at 10 at. % on which it offers lower resistivity of 1.96 × 10-4 Ω cm. From the structural studies, it is observed that the preferential orientation of all the films is along (2 1 1) plane irrespective of dopant and level of doping, but the peak intensity decreases as the doping level increases. The average transmittance of the all the films is found to be around 75% in the visible region and the optical band gap of the films are found to be in the region of 3.79-3.99 eV.

  18. Effects of ultraviolet light on B-doped CdS thin films prepared by spray pyrolysis method using perfume atomizer

    International Nuclear Information System (INIS)

    Boron doped CdS thin films were deposited by spray pyrolysis method using perfume atomizer. The effects of ultraviolet light on the structural, optical and electrical properties of B-doped CdS thin films were investigated as a function of dopant concentration (B/Cd). X-ray diffraction studies showed that all samples were polycrystalline nature with hexagonal structure. It was determined that the preferred orientation of non-illuminated samples changes from (1 0 1) to (0 0 2) with B concentration. The c lattice constant of films decreases from 6.810 Å to 6.661 Å with boron doping. The XRD peak intensity increased with the illumination for almost all the samples. The lattice parameters of B-doped samples remained nearly constant after illumination. It was found that the optical transmittance, photoluminescence spectra, resistivity and carrier concentration of the B-doped samples are stable after the illumination with UV light. Also the effects of UV light on B-doped CdS/Cu2S solar cell were investigated and it was determined that photoelectrical parameters of B-doped solar cell were more durable against the UV light.

  19. Optical and morphological investigation of aluminium and nickel oxide composite films deposited by spray pyrolysis method as a basis of solar thermal absorber

    Indian Academy of Sciences (India)

    A Bagheri Khatibani; S M Rozati

    2015-04-01

    Applications of alumina and nickel oxide in various fields specially in solar energy conversion technology encouraged us to study physical properties of such materials. Hence after the deposition of the thin films on glass substrate by spray pyrolysis, using X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV–visible spectrophotometry, various physical properties were investigated. Different optical quantities such as optical band gap, refractive index, extinction coefficient, dielectric constants, volume and surface energy loss functions and optical conductivity were determined. Within this paper for different nickel to aluminium ratio (from 20/80 to 80/20 ratio) at specific substrate temperatures (300°C), decrease of optical transmittance with nickel content was notable. Using the transmittance data, other optical quantities were achieved by a numerical approximation method. We also observed an increase in the volume energy loss (VELF) more than the surface energy loss (SELF) and simultaneously a decrease trend prevailed according to nickel amount. On the basic of the XRD results, the amorphous phase changed by the presence of more nickel and according to SEM, more obvious nanosized spherical grains at higher nickel ratios can be observed.

  20. Indium-Nitrogen Codoped Zinc Oxide Thin Film Deposited by Ultrasonic Spray Pyrolysis on n-(111 Si Substrate: The Effect of Film Thickness

    Directory of Open Access Journals (Sweden)

    Cheng-Chang Yu

    2014-01-01

    Full Text Available Indium-nitrogen codoped zinc oxide (INZO thin films were fabricated by spray pyrolysis deposition technique on n-(111 Si substrate with different film thicknesses at 450°C using a precursor containing zinc acetate, ammonium acetate, and indium nitrate with 1 : 3 : 0.05 at.% concentration. The morphology and structure studies were carried out by scanning electron microscopy (SEM and X-ray diffraction (XRD. The grain size of the films increased when increasing the film thickness. From XRD spectra, polycrystalline ZnO structure can be observed and the preferred orientation behavior varied from (002 to (101 as the film thickness increased. The concentration and mobility were investigated by Hall effect measurement. the p-type films with a hole mobility around 3 cm2V−1s−1 and hole concentration around 3×1019 cm−3 can be achieved with film thickness less than 385 nm. The n-type conduction with concentration 1×1020 cm−3 is observed for film with thickness 1089 nm. The defect states were characterized by photoluminescence. With temperature-dependent conductivity analysis, acceptor state with activation energy 0.139 eV dominate the p type conduction for thin INZO film. And the Zn-related shallow donors with activation energy 0.029 eV dominate the n-type conduction for the thick INZO film.

  1. Spray pyrolysis growth of a high figure of merit, nano-crystalline, p-type transparent conducting material at low temperature

    Science.gov (United States)

    Farrell, L.; Norton, E.; O'Dowd, B. J.; Caffrey, D.; Shvets, I. V.; Fleischer, K.

    2015-07-01

    In this letter, we demonstrate a low temperature (≈345 °C) growth method for Cu deficient CuCrO2 performed by spray pyrolysis using metal-organic precursors and a simple air blast nozzle. Smooth films were grown on glass substrates with a highest conductivity of 12 S/cm. The most conductive samples retain transparencies above 55% resulting in a figure of merit as high as 350 μS, which is the best performing p-type transparent conducting material grown by solution methods to date. Remarkably, despite the nano-crystallinity of the films, properties comparable with crystalline CuCrO2 are observed. No postannealing of the films is required in contrast to previous reports on crystalline material. The low processing temperature of this method means that the material can be deposited on flexible substrates. As this is a solution based technique, it is more attractive to industry as physical vapour deposition methods are slow and costly in comparison.

  2. Physical properties of Zn doped TiO2 thin films with spray pyrolysis technique and its effects in antibacterial activity.

    Science.gov (United States)

    Arunachalam, A; Dhanapandian, S; Manoharan, C; Sivakumar, G

    2015-03-01

    Zinc doped Titanium dioxide (TiO2: Zn) thin films were deposited onto glass substrates by the spray pyrolysis technique with the substrate temperature 450°C. The structural, optical, photoluminescence (PL) properties and morphological studies were investigated for the films deposited with various doping concentration (0, 2, 4, 6 and 8at.%) of zinc. The results of X-ray diffraction (XRD) had shown the presence of anatase peak with a strong orientation along (101) plane at 8at.% of Zn-doped TiO2 film. Scanning electron microscopy (SEM) study showed the uniform distribution of grains with porous nature. Atomic force microscopy (AFM) observations indicated the tetragonal shape at 8at.% of Zn-doped TiO2 with the particle size and decrease in surface roughness. The emission at 398nm was observed at the 8at.% of Zn-doped TiO2 thin film. The carrier concentration and Hall mobility was increased with doping. The antibacterial activity was highly yielded for the Zn-doped TiO2 thin films. PMID:25479105

  3. High power density cell using nanostructured Sr-doped SmCoO3 and Sm-doped CeO2 composite powder synthesized by spray pyrolysis

    Science.gov (United States)

    Shimada, Hiroyuki; Yamaguchi, Toshiaki; Suzuki, Toshio; Sumi, Hirofumi; Hamamoto, Koichi; Fujishiro, Yoshinobu

    2016-01-01

    High power density solid oxide electrochemical cells were developed using nanostructure-controlled composite powder consisting of Sr-doped SmCoO3 (SSC) and Sm-doped CeO2 (SDC) for electrode material. The SSC-SDC nano-composite powder, which was synthesized by spray pyrolysis, had a narrow particle size distribution (D10, D50, and D90 of 0.59, 0.71, and 0.94 μm, respectively), and individual particles were spherical, composing of nano-size SSC and SDC fragments (approximately 10-15 nm). The application of the powder to a cathode for an anode-supported solid oxide fuel cell (SOFC) realized extremely fine cathode microstructure and excellent cell performance. The anode-supported SOFC with the SSC-SDC cathode achieved maximum power density of 3.65, 2.44, 1.43, and 0.76 W cm-2 at 800, 750, 700, and 650 °C, respectively, using humidified H2 as fuel and air as oxidant. This result could be explained by the extended electrochemically active region in the cathode induced by controlling the structure of the starting powder at the nano-order level.

  4. Effects of Different Salts on Salt-Assisted Ultrasonic Spray Pyrolysis (SA-USP) Calcination for the Synthesis of Strontium Ferrite.

    Science.gov (United States)

    Hwang, Tea-Yeon; An, Guk-Hwan; Cho, Jeong-Ho; Kim, Jongryoul; Choa, Yong-Ho

    2015-10-01

    Strontium ferrite (hexaferrite), SrFe12O19, was successfully fabricated in sizes ranging from hundreds of nanometers to several micrometers by salt-assisted ultrasonic spray pyrolysis-calcination using different salt media. All samples were single phases of SrFe12O19 without the intermediate phase, α-Fe2O3, and their morphology was hexagonal. As calcination temperature increased, the size of as-calcined samples and saturation magnetization, Ms, increased while coercivity decreased. The particle size of the obtained nanoparticles varied depending on the salt media and calcination temperatures. The best magnetic properties obtained in this experiment were a coercivity of 6973 Oe with a saturation magnetization of 68.3 emu/g. To the best of our knowledge, these coercivity values are the highest ever obtained. We propose a detailed mechanism explaining the growth of these particles and conclude that the resulting single-domain particle size is about 70 nm, taking into account of factors affecting coercivity in ferrite nano- to micro-sized particles. PMID:26726463

  5. Preparation and characterizations of electroluminescent p-ZnO : N/n-ZnO : Ga/ITO thin films by spray pyrolysis method

    Science.gov (United States)

    Panatarani, C.; Fitriyadi, S.; Balasubramanian, N.; Parmar, N. S.; Joni, I. M.

    2016-02-01

    ZnO thin films were fabricated by spray pyrolysis (SP) method with p-ZnO : N/n-ZnO:Ga/ITO structure. The X-ray results show that the deposited films have hexagonal wurtzite structure. The EDS results observed that the composition of Ga in ZnO:Ga and N in ZnO:N was 3.73% and 27.73% respectively. The photoluminescence (PL) with excitation wave length of 260 nm shows that ZnO:Ga and ZnO:N films emitted UV emission at ˜393 and ˜388 nm, respectively and the films resistivity was 7.12 and 12.80 Ohm-cm respectively. The electroluminescence of the p-ZnO : N/n-ZnO:Ga/ITO structure was obtained by applying forward bias of 5 volt with 30 mA current, resulting in a 3.35 volt threshold bias with the peak electroluminescence in UV-blue range.

  6. Control of Ag nanoparticle distribution influencing bioactive and antibacterial properties of Ag-doped mesoporous bioactive glass particles prepared by spray pyrolysis.

    Science.gov (United States)

    Shih, Shao-Ju; Tzeng, Wei-Lung; Jatnika, Rifqi; Shih, Chi-Jen; Borisenko, Konstantin B

    2015-05-01

    Mesoporous bioactive glasses (MBGs) have become important bone implant materials because of their high specific surface area resulting in high bioactivity. Doping MBGs with Ag removes one of the remaining challenges to their applications, namely their lack of intrinsic antibacterial properties. In present work we demonstrate that Ag-doped MBGs can be prepared in one-step spray pyrolysis (SP) process. The SP preparation method offers the advantages of short processing times and continuous production over the sol-gel method previously used to prepare MBGs. Using scanning electron microscopy, transmission electron microscopy, and selected area electron diffraction we demonstrate that the synthesized MBG particles have amorphous structure with nanocrystalline Ag inclusions. The scanning transmission electron microscopy-X-ray energy dispersive spectrometry of cross-sectional samples shows that the distribution of the Ag dopant nanoparticles within MBGs can be controlled by using the appropriate formulation of the precursors. The distribution of the Ag dopant nanoparticles within the MBG particles was found to affect their surface areas, bioactivities and antibacterial properties. Based on the observations, we propose a mechanism describing MBG particle formation and controlling dopant distribution. PMID:25171327

  7. Preparation and characterizations of electroluminescent p-ZnO : N/n-ZnO : Ga/ITO thin films by spray pyrolysis method

    Directory of Open Access Journals (Sweden)

    C. Panatarani

    2016-02-01

    Full Text Available ZnO thin films were fabricated by spray pyrolysis (SP method with p-ZnO : N/n-ZnO:Ga/ITO structure. The X-ray results show that the deposited films have hexagonal wurtzite structure. The EDS results observed that the composition of Ga in ZnO:Ga and N in ZnO:N was 3.73% and 27.73% respectively. The photoluminescence (PL with excitation wave length of 260 nm shows that ZnO:Ga and ZnO:N films emitted UV emission at ∼393 and ∼388 nm, respectively and the films resistivity was 7.12 and 12.80 Ohm-cm respectively. The electroluminescence of the p-ZnO : N/n-ZnO:Ga/ITO structure was obtained by applying forward bias of 5 volt with 30 mA current, resulting in a 3.35 volt threshold bias with the peak electroluminescence in UV-blue range.

  8. Catalytic conversion of biomass pyrolysis-derived compounds with chemical liquid deposition (CLD) modified ZSM-5.

    Science.gov (United States)

    Zhang, Huiyan; Luo, Mengmeng; Xiao, Rui; Shao, Shanshan; Jin, Baosheng; Xiao, Guomin; Zhao, Ming; Liang, Junyu

    2014-03-01

    Chemical liquid deposition (CLD) with KH550, TEOS and methyl silicone oil as the modifiers was used to modify ZSM-5 and deposit its external acid sites. The characteristics of modified catalysts were tested by catalytic conversion of biomass pyrolysis-derived compounds. The effects of different modifying conditions (deposited amount, temperature, and time) on the product yields and selectivities were investigated. The results show KH550 modified ZSM-5 (deposited amount of 4%, temperature of 20°C and time of 6h) produced the maximum yields of aromatics (24.5%) and olefins (16.5%), which are much higher than that obtained with original ZSM-5 catalyst (18.8% aromatics and 9.8% olefins). The coke yield decreased from 44.1% with original ZSM-5 to 26.7% with KH550 modified ZSM-5. The selectivities of low-molecule-weight hydrocarbons (ethylene and benzene) decreased, while that of higher molecule-weight hydrocarbons (propylene, butylene, toluene, and naphthalene) increased comparing with original ZSM-5. PMID:24413482

  9. Bio-oils from biomass slow pyrolysis: a chemical and toxicological screening.

    Science.gov (United States)

    Cordella, Mauro; Torri, Cristian; Adamiano, Alessio; Fabbri, Daniele; Barontini, Federica; Cozzani, Valerio

    2012-09-15

    Bio-oils were produced from bench-scale slow-pyrolysis of three different biomass samples (corn stalks, poplar and switchgrass). Experimental protocols were developed and applied in order to screen their chemical composition. Several hazardous compounds were detected in the bio-oil samples analysed, including phenols, furans and polycyclic aromatic hydrocarbons. A procedure was outlined and applied to the assessment of toxicological and carcinogenic hazards of the bio-oils. The following hazardous properties were considered: acute toxicity; ecotoxicity; chronic toxicity; carcinogenicity. Parameters related to these properties were quantified for each component identified in the bio-oils and overall values were estimated for the bio-oils. The hazard screening carried out for the three bio-oils considered suggested that: (i) hazards to human health could be associated with chronic exposures to the bio-oils; (ii) acute toxic effects on humans and eco-toxic effects on aquatic ecosystems could also be possible in the case of loss of containment; and (iii) bio-oils may present a marginal potential carcinogenicity. The approach outlined allows the collection of screening information on the potential hazards posed by the bio-oils. This can be particularly useful when limited time and analytical resources reduce the possibility to obtain detailed specific experimental data. PMID:22790394

  10. Physical and Chemical Properties of Bio-Oils From Microwave Pyrolysis of Corn Stover

    Science.gov (United States)

    Yu, Fei; Deng, Shaobo; Chen, Paul; Liu, Yuhuan; Wan, Yiqin; Olson, Andrew; Kittelson, David; Ruan, Roger

    This study was aimed to understand the physical and chemical properties of pyrolytic bio-oils produced from microwave pyrolysis of corn stover regarding their potential use as gas turbine and home heating fuels. The ash content, solids content, pH, heating value, minerals, elemental ratio, moisture content, and viscosity of the bio-oils were determined. The water content was approx 15.2 wt%, solids content 0.22 wt%, alkali metal content 12 parts per million, dynamic viscosity 185 mPa·s at 40°C, and gross high heating value 17.5 MJ/kg for a typical bio-oil produced. Our aging tests showed that the viscosity and water content increased and phase separation occurred during the storage at different temperatures. Adding methanol and/or ethanol to the bio-oils reduced the viscosity and slowed down the increase in viscosity and water content during the storage. Blending of methanol or ethanol with the bio-oils may be a simple and cost-effective approach to making the pyrolytic bio-oils into a stable gas turbine or home heating fuels.

  11. Chemical properties of bio-oils produced by fast pyrolysis of bamboo

    OpenAIRE

    Kato, Yoshiaki; Kohnosu, Taku; Enomoto, Ryohei; Akazawa, Minami; Yoon, Seung-Lak; Kojima, Yasuo

    2014-01-01

    Bamboo powder was analytically pyrolyzed using pyrolysis-gas chromatography (Py-GC), and the effects of fast pyrolysis conditions on the product distribution of bio-oil were evaluated. 4-Vinylphenol (4VP) was identified as a major product of bamboo fast pyrolysis by ^1H-NMR and ^C-NMR spectrometry. The formation pathway of 4VP demonstrated that p-coumarate esters are present in bamboo lignin, and 4VP is likely to be derived from these p-coumarate structures. The evaluation of the effect of fa...

  12. Slow pyrolysis of prot, alkali and dealkaline lignins for production of chemicals.

    Science.gov (United States)

    Biswas, Bijoy; Singh, Rawel; Kumar, Jitendra; Khan, Adnan Ali; Krishna, Bhavya B; Bhaskar, Thallada

    2016-08-01

    Effect of different lignins were studied during slow pyrolysis. Maximum bio-oil yield of 31.2, 34.1, and 29.5wt.% was obtained at 350, 450 and 350°C for prot lignin, alkali lignin and dealkaline lignin respectively. Maximum yield of phenolic compounds 78%, 80% and 92% from prot lignin, alkali and dealkaline lignin at 350, 450 and 350°C. The differences in the pyrolysis products indicated the source of lignins such as soft and hard wood lignins. The biochar characterisation revealed that the various ether linkages were broken during pyrolysis and lignin was converted into monomeric substituted phenols. Bio-oil showed that the relative contents of each phenolic compound changes significantly with pyrolysis temperature and also the relative contents of each compound changes with different samples. PMID:26873286

  13. Synthesis and characterization of boron-doped NiO thin films pro-duced by spray pyrolysis

    Institute of Scientific and Technical Information of China (English)

    U Alver; H Yaykasl; S Kerli; A Tanrverdi

    2013-01-01

    Boron-doped NiO thin films were prepared on glass substrates at 400◦C by airbrush spraying method using a solution of nickel nitrate hexahydrate. Their physical properties were investigated as a function of dopant concentration. From X-ray diff raction patterns, it is observed that the films have cubic structure with lattice parameters varying with boron concentration. The morphologies of the films were examined by using scanning electron microscopy, and the grain sizes were measured to be around 30-50 nm. Optical measurements show that the band gap energies of the films first decrease then increase with increasing boron concentration. The resistivities of the films were determined by four point probe method, and the changes in resistivity with boron concentration were investigated.

  14. Spray pyrolysis deposition of Cu-ZnO and Zn-SnO{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Khelfane, A.; Tarzalt, H.; Sebboua, B.; Zerrouki, H.; Kesri, N., E-mail: kesri5n@gmail.com [Faculty of Physics, University of Science and Technology of Houari Boumediene, Algiers (Algeria)

    2015-12-31

    Large-gap metal oxides, such as titanium, tin, and zinc oxides, have attracted great interest because of their remarkable potential in dye-sensitized solar cells (DSSC) and their low cost and simple preparation procedure. In this work, we investigated several Zn-SnO{sub 2} and Cu-ZnO thin films that were sprayed under different experimental conditions. We varied [Zn/[Sn] and [Cu/[Zn] ratios, calculated on atomic percent in the starting solution. We report some structural results of the films using X-ray diffraction. Optical reflection and transmission spectra investigated by an UV/VIS/NIR spectrophotometer permit the determination of optical constants. The direct band gap was deduced from the photon energy dependence of the absorption coefficient.

  15. Structural and fluorescence properties of Ni:MgO-SiO2 particles synthesized by flame spray pyrolysis

    International Nuclear Information System (INIS)

    Structural and fluorescence properties of flame spray-synthesized Ni 1 mol%-doped MgO-SiO2 nano-particles (MgO:SiO2 = 100:0, 50:50, 25:75 and 0:100 in mol%) were investigated as a first step to prepare transparent materials containing Ni:MgO for optical gain media. Polyhedral aggregates of primary particles with diameters of 8-19 nm were obtained for all compositions. The 100MgO particles were single crystalline and showed the fluorescences (centered at 1260 and 1320 nm) and lifetime (3.8 ms) similar to those of solid state-synthesized Ni:MgO polycrystalline powder under laser excitation at 976 nm, suggesting Ni ions incorporated in MgO

  16. Spray generator of singlet oxygen for a chemical oxygen-iodine laser

    Czech Academy of Sciences Publication Activity Database

    Jirásek, Vít; Hrubý, Jan; Špalek, Otomar; Čenský, Miroslav; Kodymová, Jarmila

    2010-01-01

    Roč. 100, č. 4 (2010), s. 779-791. ISSN 0946-2171 Grant ostatní: European Office of Aerospace R&D(US) FA8655-09-1-3091 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20760514 Keywords : spray generator of singlet oxygen * singlet oxygen * chemical oxygen-iodine laser Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.239, year: 2010

  17. Preparation of Al2O3/Mo nanocomposite powder via chemical route and spray drying

    International Nuclear Information System (INIS)

    A route to prepare nanometer-sized Mo particulates in Al2O3 was attempted by a combination of solution reactions in molecular scale and forcing precipitation by a spray-drying technique. MoO3 was first dissolved in ammonia water and then added in the slurry with high purity, submicrometer Al2O3 powder. Mixed suspension was spray-dried, and then the dried granules were reduced by hydrogen gas and further hot-pressing to a bulky composite at various temperatures. Dissolution of Mo oxide, adsorption reactions on alumina surface, and surface potential of alumina particles in homogeneous ammonia suspension were studied. Characterization of the granules, including compactability, flowing properties, surface morphology, grain growth of Mo and Al2O3, and mixing homogeneity, were examined. Homogeneity of the spray-dried granules was determined by the calculation of mixing index and the observation of the microstructure of sintered body. The existence of intergranular, intragranular, and nanosized Mo particulates within Al2O3 grains was observed by transmission electron microscopy (TEM). All the evidences revealed that homogeneous composites with nanometer-sized Mo had been successfully prepared by this attempt with the proposed chemical route and following spray-drying process. copyright 1996 Materials Research Society

  18. Soil organic degradation: bridging the gap between Rock-Eval pyrolysis and chemical characterization (CPMAS 13C NMR)

    Science.gov (United States)

    Albrecht, Remy; Sebag, David; Verrecchia, Eric

    2013-04-01

    Being a source of mineral nutrients, organic matter contributes to soil chemical fertility and acts on soil physical fertility through its role in soil structure. Soil organic matter (SOM) is a key component of soils. Despite the paramount importance of SOM, information on its chemistry and behaviour in soils is incomplete. Numerous methods are used to characterize and monitor OM dynamics in soils using different approaches (Kogel-Knabner, 2000). Two of the main approaches are evaluated and compared in this study. Rock-Eval pyrolysis (RE pyrolysis) provides a description of a SOM's general evolution using its thermal resistance. The second tool (13C CPMAS NMR) aims to give precise and accurate chemical information on OM characterization. The RE pyrolysis technique was designed for petroleum exploration (Lafargue et al., 1998) and because of its simplicity, it has been applied to a variety of other materials such as soils or Recent sediments (Disnar et al., 2000; Sebag, 2006). Recently, RE pyrolysis became a conventional tool to study OM dynamics in soils. In RE pyrolysis, a peak deconvolution is applied to the pyrolysis signal in order to get four main components related to major classes of organic constituents. These components differ in origin and resistance to pyrolysis: labile biological constituents (F1), resistant biological constituents (F2), immature non-biotic constituents (F3) and a mature refractory fraction (F4) (Sebag, 2006; Coppard, 2006). Main advantages of the technique are its repeatability, and rapidity to provide an overview of OM properties and stocks. However, do the four major classes used in the literature reflect a pertinent chemical counterpart? To answer this question, we used 13C Nuclear Magnetic Resonance Spectroscopy in the solid state (13C CPMAS NMR) to collect direct information on structural and conformational characteristics of OM. NMR resonances were assigned to chemical structures according to five dominant forms: alkyl C, O

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

    International Nuclear Information System (INIS)

    Nanostructured tin oxide films were prepared by depositing different sols using the so-called spray-gel pyrolysis process. SnO2 suspensions (sols) were obtained from tin (IV) tert-amyloxide (Sn(t-OAm)4) or tin (IV) chloride pentahydrate (SnCl4.5H2O) 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. SnO2 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 SnCl4.5H2O 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

  20. Structural, optical and electrical properties of ZnO thin films prepared by spray pyrolysis: Effect of precursor concentration

    Indian Academy of Sciences (India)

    F Zahedi; R S Dariani; S M Rozati

    2014-05-01

    ZnO thin films have been prepared using zinc acetate precursor by spray pyrolytic decomposition of zinc acetate on glass substrates at 450 °C. Effect of precursor concentration on structural and optical properties has been investigated. ZnO films are polycrystalline with (002) plane as preferential orientation. The optical transmission spectrum shows that transmission increases with decrease in the concentration and the maximum transmission in visible region is about 95% for ZnO films prepared with 0.1 M. The direct band-gap value decreases from 3.37 to 3.19 eV, when the precursor concentration increases from 0.1 to 0.4 M. Photoluminescence spectra at room temperature show an ultraviolet (UV) emission at 3.26 eV and two visible emissions at 2.82 and 2.38 eV. Lowest resistivity is obtained at 2.09 cm for 0.3 M. The current–voltage characteristic of the ZnO thin films were measured in dark and under UV illumination. The values of photocurrent and photoresponsivity at 5 V are increased with increase in precursor concentration and reaches to maximum value of 1148 A and 0.287 A/W, respectively which is correlated to structural properties of ZnO thin films.

  1. A study of the photoconductivity and thermoelectric properties of SnxSy optical semiconductor thin films deposited by the spray pyrolysis technique

    International Nuclear Information System (INIS)

    In this paper, thin films of tin sulfide (SnxSy) with atomic ratios of y/x=0.25, 0.50, 0.75, 1.00, 1.25 and 1.50 have been prepared on a glass substrate at T=420 deg. C using the spray pyrolysis technique. The initial materials for the preparation of thin films were an alcoholic solution consisting of tin chloride (SnCl4.5H2O) and thiourea (CS(NH3)2). The prepared thin films were characterized by x-ray diffraction, scanning electron microscopy, energy dispersive x-ray analysis, scanning helium ion microscopy and UV-vis spectroscopy. The photoconductivity and thermoelectric effects of SnxSy thin films have been studied. The SnxSy thin films had a polycrystalline structure with a nearly uniform surface and cluster-type growth. With increasing the atomic ratio of (y/x) in films, the optical gap, photosensitivity, thermal activation energy and Seebeck coefficient changed from 2.72 to 2.37 eV, from 0.05 to 0.78, from 0.07 to 0.48 eV (in the high temperature range) and from +0.17 to -0.22 mV K-1 (at T=350 K), respectively. In addition, the structure of tin sulfide thin films tends to a nearly single-crystal state in (001) preferred orientation corresponding to SnS2 phase with increasing (y/x) ratio. These structure situations considerably influence the photosensitivity and thermoelectric properties of thin films.

  2. Structural, photoconductive, thermoelectric and activation energy measurements of $V$-doped transparent conductive $SnO_{2}$ films fabricated by spray pyrolysis technique

    Indian Academy of Sciences (India)

    R NASIRAEI; M R FADAVIESLAM; H AZIMI-JUYBARI

    2016-08-01

    This report investigated the structural, optical and electrical properties of V-doped $SnO_{2}$ thin films deposited using spray pyrolysis technique. The $SnO_{2}$:$V$ films, with different $V$-content, were deposited on glasssubstrates at a substrate temperature of $550\\deg C$ using an aqueous ethanol solution consisting of tin and vanadium chloride. X-ray diffraction studies showed that the $SnO_{2}$:$V$ films were polycrystalline only with tin oxide phasesand the preferred orientations are along (1 1 0), (1 0 1), (2 1 1) and (3 0 1) planes. Using Scherrer formula, the grain sizes were estimated to be within the range of 25--36 nm. The variation in sheet resistance and optical direct band gap are functions of vanadium doping concentration. Field emission scanning electron microscopy (FESEM) revealed the surface morphology to be very smooth, yet grainy in nature. Optical transmittance spectra of the films showed high transparency of about $\\approx 69--90%$ in the visible region, decreasing with increase in $V$-doping. The direct band gap for undoped $SnO_{2}$ films was found to be 3.53 eV, while for higher V-doped films it shifted toward lower energies in the range of 3.27--3.53 eV and then increased again to 3.5 eV. The Hall effect and Seebeck studies revealed that the films exhibit n-type conductivity. The thermal activation energy, Seebeck coefficient and maximum of photosensitivity in the films were found to be in the range of 0.02--0.82 eV (in thelow-temperature range), $0.15--0.18 {\\rm mV K^{−1}}$ (at $T = 350 K$) and 0.96--2.84, respectively.

  3. Comparative studies of CdS, CdS:Al, CdS:Na and CdS:(Al-Na) thin films prepared by spray pyrolysis

    Science.gov (United States)

    Yılmaz, S.; Atasoy, Y.; Tomakin, M.; Bacaksız, E.

    2015-12-01

    In the present study, the spray pyrolysis technique was used to prepare pure CdS, 4 at.% Al-doped CdS, 4 at.% Na-doped CdS and (4 at.% Al, 4 at.% Na)-co-doped CdS thin films. It was found from X-ray diffraction data that all the specimens showed hexagonal wurtzite structure with the preferred orientation of (101). Scanning electron microscopy results indicated that 4 at.% Al-doping caused a grain growth in the morphology of CdS thin films whereas the 4 at.% Na-doping and (4 at.% Al, 4 at.% Na)-co-doping led to porous structure with small grains. The band gap value of CdS thin films increased to 2.42 eV after 4 at.% Al-doping. However, it reduced to 2.30 eV and 2.08 eV for 4 at.% Na-doping and (4 at.% Al, 4 at.% Na)-co-doping, respectively. The room temperature photoluminescence measurements illustrated that the peak intensity of CdS thin films enhanced with 4 at.% Al-doping while 4 at.% Na-doping and (4 at.% Al, 4 at.% Na)-co-doping caused a decline in the intensity. The maximum carrier concentration and minimum resistivity were obtained for 4 at.% Al-doped CdS thin films, which is associated with the grain growth. Furthermore, (4 at.% Al, 4 at.% Na)-co-doping gave rise to a slight reduction in the carrier concentration and a slight increment in the resistivity. As a result, it can be said that 4 at.% Al-doped CdS thin films exhibited the best electrical and optical properties, which is important for the opto-electronic applications.

  4. Synthesis of Zn1- x Co x Al2O4 Spinel Nanoparticles by Liquid-Feed Flame Spray Pyrolysis: Ceramic Pigments Application

    Science.gov (United States)

    Betancur Granados, Natalia; Yi, Eongyu; Laine, Richard M.; Restrepo Baena, Oscar Jaime

    2016-01-01

    Zn1- x Co x Al2O4 ( x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) spinel nanoparticles were synthesized by a liquid-feed flame spray pyrolysis (LF-FSP) method by combusting metallorganic precursor solutions to produce nanopowders with precise composition control. The precursor solutions were aerosolized into a methane/oxygen flame where it was combusted in an oxygen-rich environment to result in nanopowders at a single step. The nanopowders were analyzed by x-ray diffraction, Fourier transform infrared spectroscopy, colorimetry, field emission scanning electron microscopy, transmission electron microscopy, and BET (Brunauer-Emmett-Teller) N2 adsorption. Results show formation of spherical nanopowders with specific surface areas of 42 m2/g to 50 m2/g, which correspond to average particle sizes of 26 nm to 31 nm. Single-phase materials were obtained with a high control of composition, which indicates that LF-FSP is an excellent method to produce mixed-metal oxides for applications in which powder homogeneity is crucial. The products were evaluated for ceramic pigment application, where the ratio of Zn to Co was gradually changed to observe the color change in the structure with the increase of cobalt concentration. The resulting pigments were calcined at 1200°C, which aimed to identify the color stability after a high-temperature process, whereby the colors were measured using the color space CIE L*a*b* under standardized light, D65. Finally, the powders were tested for ceramic decoration using transparent glazes and ceramic bodies. The application was carried out at 1250°C to evaluate the color performance after a decoration process.

  5. Chemical oxygen-iodine laser with a centrifugal spray generator of singlet oxygen

    Czech Academy of Sciences Publication Activity Database

    Špalek, Otomar; Jirásek, Vít; Čenský, Miroslav; Kodymová, Jarmila

    Bellingham: SPIE, 2010 - (Dreischuh, T.; Atanasov, P.; Sabotinov, N.), 77510H/1-77510H/9. (Proceedings of SPIE. 7751). ISBN 978-0-8194-8242-6. ISSN 0277-786X. [International Symposium on Gas Flow and Chemical lasers and High Power Lasers /18./. Sofia (BG), 30.08.2010-03.09.2010] Grant ostatní: US Air Force EOARD (European Office of Aerospace R&D)(US) FA8655-09-1-3091 Institutional research plan: CEZ:AV0Z10100523 Keywords : chemical oxygen-iodine laser * COIL * spray generator * singlet oxygen * centrifugal separation Subject RIV: BH - Optics, Masers, Lasers http://dx.doi.org/12.880740

  6. The KIVA-2 computer program for transient multidimensional chemically reactive flows with sprays

    Science.gov (United States)

    Amsden, A. A.; Butler, T. D.; Orourke, P. J.

    Since its public release in 1985, the KIVA computer program has been utilized for the time dependent analysis of chemically reacting flows with sprays in two and three space dimensions. This paper describes some of the improvements to the original version that have been made since that time. The new code called KIVA-2 is planned for public release in early 1988. KIVA-2 improves the earlier version in the accuracy and efficiency of the computational procedure, the accuracy of the physics submodels, and in versatility and ease of use. Numerical improvements include the use of the ICE solution procedure in place of the acoustic subcycling method and the implementation of a quasi-second-order-accurate convection scheme. Major extensions to the physical submodels include the inclusion of an optional kappa-epsilon turbulence model, and several additions to the spray model. We illustrate some of the new capabilities by means of example solutions.

  7. Relationship between chemical composition and pyrolysis behaviour of a medium temperature pitch (or Lurgi-gasifier pitch)

    OpenAIRE

    Sima, L.; Blanco Rodríguez, Clara; Santamaría Ramírez, Ricardo; Granda Ferreira, Marcos; Slaghuis, H.; Menéndez López, Rosa María

    2003-01-01

    This paper studies the chemical composition and pyrolysis behaviour of a medium temperature pitch produced in the SASOL–Lurgi coal gasification process. The results are compared to a commercial petroleum pitch and a commercial binder coal-tar pitch. The SASOL pitch had a high content in oxygen, mainly forming phenols, which make it very reactive at temperatures between 410 and 430 °C, temperatures at which the commercial pitches do not react in a great extent. Despite the high reactivity show...

  8. The Chemical Composition and Physical Properties of the Light and Heavy Tar Resulted from Coconut Shell Pyrolysis

    OpenAIRE

    Uswatun Hasanah; Bambang Setiaji3); Triyono Triyono; Chairil Anwar

    2012-01-01

    The tar resulted from pyrolysis of coconut shell is a waste. It is important to be clarified their chemical composition and physical properties in order to find out their feasibility as source of a fuel. This research was resulted two immiscible organic fractions, and these were further determined their physical properties such as water composition by using ASTM D-95 methods, ash composition (ASTM D-482), flash point C.O.C (ASTM D-92), kinematics of viscosity (ASTM D-445), and caloric valued ...

  9. Electrochemical properties of nano-sized LiNi1/3Co1/3Mn1/3O2 powders in the range from 56 to 101 nm prepared by flame spray pyrolysis

    International Nuclear Information System (INIS)

    Graphical abstract: Nano-sized LiNi1/3Co1/3Mn1/3O2 powders are prepared by flame spray pyrolysis. A lithium excess of 15% of the stoichiometric amount in the spray solution produced powder with good electrochemical properties for use as a cathode. The mean particle sizes of the powders post-treated at 700 and 800 °C are 56 and 101 nm, respectively. The powder prepared with 15% excess lithium results in the highest initial discharge capacity of 174 mAh g−1. Highlights: ► Nano-sized LiNi1/3Co1/3Mn1/3O2 powders are prepared directly by flame spray pyrolysis. ► The mean particle sizes of the powders post-treated at 700 and 800 °C are 56 and 101 nm, respectively. ► The powder prepared with 15% excess lithium results in the highest initial discharge capacity of 174 mAh g−1. - Abstract: Nano-sized LiNi1/3Co1/3Mn1/3O2 powders in the range from 56 to 101 nm with hexagonal α-NaFeO2 structures are prepared directly by flame spray pyrolysis. Post-treatment of the powders at 700 °C increases their crystallinity and mean particle sizes. The intensity ratios of the powders’ (0 0 3) and (1 0 4) peaks in the XRD patterns prepared from spray solutions with lithium excesses of 10, 15 and 20% of the stoichiometric amount are 0.83, 1.25 and 1.25, respectively. The powder prepared with 15% excess lithium results in the highest initial discharge capacity of 174 mAh g−1 when post-treated at 700 °C. The discharge capacity of the powder post-treated at 800 °C decreases from 168 to 120 mAh g−1 after 30 cycles.

  10. Offgas Analysis and Pyrolysis Mechanism of Activated Carbon from Bamboo Sawdust by Chemical Activation With KOH

    Institute of Scientific and Technical Information of China (English)

    TIAN Yong; LIU Ping; WANG Xiufang; ZHONG Guoying; CHEN Guanke

    2011-01-01

    Bamboo sawdust was used as the precursor for the multipurpose use of waste.Offgases released during the activation process of bamboo by KOH were investigated quantitatively and qualitatively by a gas analyzer. TG/DTG curves during the pyrolysis process with different impregnation weight ratios (KOH to bamboo) were obtained by a thermogravimetric analyzer. Pyrolysis mechanism of bamboo was proposed. The results showed that the offgases were composed of CO, NO,SO2 and hydrocarbon with the concentration of 1 372, 37, 86, 215 mg/L, respectively. Thermogravimetric analysis indicated that the pyrolytic process mainly experienced two steps. The first was the low temperature activation step (lower than 300 ℃), which was the pre-activation and induction period.The second was the high temperature activation step(higher than 550 ℃), which was a radial activation followed by pore production. The second process was the key to control the pore distribution of the final product.

  11. Pt-doped In{sub 2}O{sub 3} nanoparticles prepared by flame spray pyrolysis for NO{sub 2} sensing

    Energy Technology Data Exchange (ETDEWEB)

    Inyawilert, K. [Chiang Mai University, Department of Physics and Materials Science, Faculty of Science (Thailand); Channei, D. [Naresuan University, Department of Chemistry, Faculty of Science (Thailand); Tamaekong, N. [Maejo University, Program in Materials Science, Faculty of Science (Thailand); Liewhiran, C. [Chiang Mai University, Department of Physics and Materials Science, Faculty of Science (Thailand); Wisitsoraat, A.; Tuantranont, A. [National Electronics and Computer Technology Center (NECTEC), Nanoelectronics and MEMS Laboratory (Thailand); Phanichphant, S., E-mail: sphanichphant@gmail.com [Chiang Mai University, Faculty of Science, Materials Science Research Center (Thailand)

    2016-02-15

    Undoped In{sub 2}O{sub 3} and 0.25–1.00 wt% M (M=Pt, Nb, and Ru)-doped/loaded In{sub 2}O{sub 3} nanoparticles were successfully synthesized in a single-step flame spray pyrolysis technique using indium nitrate, platinum (II) acetylacetonate, niobium ethoxide, and ruthenium (III) acetylacetonate precursors. The undoped In{sub 2}O{sub 3} and M-doped In{sub 2}O{sub 3} nanoparticles were characterized by Brunauer–Emmett–Teller (BET) analysis, X-ray diffraction (XRD), and scanning and transmission electron microscopy (SEM & TEM). The BET average diameter of spherical nanoparticles was found to be in the range of 10.2–15.2 nm under 5/5 (precursor/oxygen) flame conditions. All XRD peaks were confirmed to correspond to the cubic structure of In{sub 2}O{sub 3}. TEM images showed that there is no Pt nanoparticle loaded on In{sub 2}O{sub 3} surface, suggesting that Pt should form solid solution with the In{sub 2}O{sub 3} lattice. Gas sensing studies showed that 0.5 wt% Pt doping in In{sub 2}O{sub 3} nanoparticles gave a significant enhancement of NO{sub 2} sensing performances in terms of sensor response and selectivity. 0.5 wt% Pt/In{sub 2}O{sub 3} exhibited a high NO{sub 2} response of ∼1904 to 5 ppm NO{sub 2} at 250 °C and good NO{sub 2} selectivity against NO, H{sub 2}S, H{sub 2}, and C{sub 2}H{sub 5}OH. In contrast, Nb and Ru loading resulted in deteriorated NO{sub 2} response. Therefore, Pt is demonstrated to be an effective additive to enhance NO{sub 2} sensing performances of In{sub 2}O{sub 3}-based sensors.

  12. KIVA-2: A computer program for chemically reactive flows with sprays

    Science.gov (United States)

    Amsden, A. A.; Orourke, P. J.; Butler, T. D.

    1989-05-01

    This report documents the KIVA-2 computer program for the numerical calculation of transient, two- and three-dimensional, chemically reactive fluid flows with sprays. KIVA-2 extends and enhances the earlier KIVA code, improving its computational accuracy and efficiency and its ease-of-use. The KIVA-2 equations and numerical solution procedures are very general and can be applied to laminar or turbulent flows, subsonic or supersonic flows, and single-phase or dispersed two-phase flows. Arbitrary numbers of species and chemical reactions are allowed. A stochastic particle method is used to calculate evaporating liquid sprays, including the effects of droplet collisions and aerodynamic breakups. Although the initial and boundary conditions and mesh generation have been written for internal combustion engine calculations, the logic for these specifications can be easily modified for a variety of other applications. Following an overview of the principal features of the KIVA-2 program, we describe in detail the equations solved, the numerical solution procedure, and the structure of the computer program. Sixteen appendices provide additional details concerning the numerical solution procedure.

  13. FAST PYROLYSIS OF LIGNINS

    OpenAIRE

    Sedat Beis; Saikrishna Mukkamala; Nathan Hill; Jincy Joseph; Cirila Baker; Bruce Jensen; Elizabeth Stemmler; Clayton Wheeler; Brian Frederick; Adriaan van Heiningen; Alex Berg; William Joseph DeSisto

    2010-01-01

    Three lignins: Indulin AT, LignoboostTM, and Acetocell lignin, were characterized and pyrolyzed in a continuous-fed fast pyrolysis process. The physical and chemical properties of the lignins included chemical composition, heat content, ash, and water content. The distributed activation energy model (DAEM) was used to describe the pyrolysis of each lignin. Activation energy distributions of each lignin were quite different and generally covered a broad range of energies, typically found in li...

  14. Investigation of Chemical Kinetics on Soot Formation Event of n-Heptane Spray Combustion

    DEFF Research Database (Denmark)

    Pang, Kar Mun; Jangi, Mehdi; Bai, Xue-Song;

    2014-01-01

    In this reported work, 2-dimsensional computational fluid dynamics studies of n-heptane combustion and soot formation processes in the Sandia constant-volume vessel are carried out. The key interest here is to elucidate how the chemical kinetics affects the combustion and soot formation events....... Numerical computation is performed using OpenFOAM and chemistry coordinate mapping (CCM) approach is used to expedite the calculation. Three n-heptane kinetic mechanisms with different chemistry sizes and comprehensiveness in oxidation pathways and soot precursor formation are adopted. The three examined...... chemical models use acetylene (C2H2), benzene ring (A1) and pyrene (A4) as soot precursor. They are henceforth addressed as nhepC2H2, nhepA1 and nhepA4, respectively for brevity. Here, a multistep soot model is coupled with the spray combustion solver to simulate the soot formation/oxidation processes...

  15. Relationships between Chemical Characteristics and Phytotoxicity of Biochar from Poultry Litter Pyrolysis.

    Science.gov (United States)

    Rombolà, Alessandro G; Marisi, Giovanni; Torri, Cristian; Fabbri, Daniele; Buscaroli, Alessandro; Ghidotti, Michele; Hornung, Andreas

    2015-08-01

    Three biochars were prepared by intermediate pyrolysis from poultry litter at different temperatures (400, 500, and 600 °C with decreasing residence times) and compared with biochars from corn stalk prepared under the same pyrolysis conditions. The phytotoxicity of these biochars was estimated by means of seed germination tests on cress (Lepidium sativum L.) conducted in water suspensions (at 2, 5, and 40 g/L) and on biochars wetted according to their water-holding capacity. Whereas the seeds germinated after 72 h in water suspensions with corn stalk biochar were similar to the control (water only), significant inhibition was observed with poultry litter biochars. In comparison to corn stalk, poultry litter generated biochars with higher contents of ash, ammonium, nitrogen, and volatile fatty acids (VFAs) and a similar concentration of polycyclic aromatic hydrocarbons (PAHs). Results from analytical pyrolysis (Py-GC-MS) indicated that nitrogen-containing organic compounds (NCCs) and aliphatic components were distinctive constituents of the thermally labile fraction of poultry litter biochar. The inhibition of germination due to poultry litter biochar produced at 400 °C (PL400) was suppressed after solvent extraction or treatment with active sludge. A novel method based on solid-phase microextraction (SPME) enabled the identification of mobile organic compounds in PL400 capable of being released in air and water, including VFAs and NCCs. The higher phytotoxicity of poultry litter than corn biochars was tentatively attributed to hydrophilic biodegradable substances derived from lipids or proteins removable by water leaching or microbial treatments. PMID:26151387

  16. Estimation of Arrhenius parameters for the 1,1 elimination of H2 from Si2H6 and the role of chemically activated disilane in silane pyrolysis

    International Nuclear Information System (INIS)

    This paper analyzes the Arrhenius parameters for the 1,1 H2 dissociation channel reaction rate for the disilane thermal decomposition. The RRKM model is used to estimate these arrhenius parameters. The role that chemically active disilane plays in the pyrolysis of silanes is also discussed. The estimate of the heat of formation of H3SiSiH is determined also

  17. Pyrolysis and Gasification

    DEFF Research Database (Denmark)

    Astrup, Thomas; Bilitewski, B.

    2011-01-01

    incineration capacity, but also a better ability of gasification over incineration to preserve the chemical energy of the waste is important. This chapter provides an overview of pyrolysis and gasification processes related to waste, the technology involved, energy recovery options, and important environmental......Pyrolysis and gasification include processes that thermally convert carbonaceous materials into products such as gas, char, coke, ash, and tar. Overall, pyrolysis generates products like gas, tar, and char, while gasification converts the carboncontaining materials (e.g. the outputs from pyrolysis......) into a mainly gaseous output. The specific output composition and relative amounts of the outputs greatly depend on the input fuel and the overall process configuration. Although pyrolysis processes in many cases also occur in gasification (however prior to the gasification processes), the overall...

  18. Chemical composition of Titan's aerosols analogues characterized with a systematic pyrolysis-gas chromatography-mass spectrometry characterization

    Science.gov (United States)

    Szopa, Cyril; Raulin, Francois; Coll, Patrice; Cabane, Michel; GCMS Team

    2014-05-01

    The in situ chemical characterization of Titan's atmosphere was achieved in 2005 with two instruments present onboard the Huygens atmospheric probe : the Aerosol Collector and Pyrolyzer (ACP) devoted to collect and pyrolyse Titan's aerosols ; the Gas Chromatograph-Mass Spectrometer (GCMS) experiment devoted to analyze gases collected in the atmosphere or coming from the aerosols pyrolysis. The GCMS was developed by Hasso Niemann in the filiation of the quadrupole mass spectrometers he built for several former space missions. The main objectives were to : determine the concentration profile of the most abundant chemical species; seek for minor atmospheric organic species not detected with remote observations ; give a first view of the organic aerosols structure; characterize the condensed volatiles present at the surface (e.g. lakes) in case of survival of the probe to the landing impact. Taking into account for the potential complexity of the gaseous samples to be analyzed, it was decided to couple to the MS analyzer a gas chromatograph capable to separate volatile species from light inorganic molecules and noble gases, to organic compounds including aromatics. This was the first GCMS analyzer that worked in an extraterrestrial environment since the Viking missions on Mars. Even if the GCMS coupling mode did not provide any result of interest, it has been demonstrated to be functional during the Huygens descent. But, the direct MS analysis of the atmosphere, and the pyrolysis-MS analysis of aerosols allowed to make great discoveries which are still of primary importance to describe the Titan's lower atmosphere composition. This contribution aims at presenting this instrument that worked in the Titan's atmosphere, and summarizing the most important discoveries it allowed.

  19. [Analysis of exposure to pepper spray as a part of preparing hospital to help victims of mass chemical incidents].

    Science.gov (United States)

    Chwaluk, Paweł; Topczewska, Elzbieta; Barwina, Małgorzata

    2012-01-01

    We analyzed an incident of exposure to pepper spray 35 persons, including 29 children. Medical procedures were difficult because of the lack of reliable information about the nature of exposure, lack of hospital action plan for chemical accidents and established principles of cooperation with poison control center, as well as the need of extensive medical documentation for each patient. PMID:23243951

  20. Influence of precursor solution parameters on chemical properties of calcium phosphate coatings prepared using Electrostatic Spray Deposition (ESD).

    NARCIS (Netherlands)

    Leeuwenburgh, S.C.G.; Wolke, J.G.C.; Schoonman, J.; Jansen, J.A.

    2004-01-01

    A novel coating technique, referred to as Electrostatic Spray Deposition (ESD), was used to deposit calcium phosphate (CaP) coatings with a variety of chemical properties. The relationship between the composition of the precursor solutions and the crystal and molecular structure of the deposited coa