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Sample records for sputtered blocking layer

  1. Formation of biocompatible surface layers depending on the sputtering distance

    Science.gov (United States)

    Nasakina, E. O.; Seregin, A. V.; Baikin, A. S.; Kaplan, M. A.; Konushkin, S. V.; Sergiyenko, K. V.; Kovaleva, E. D.; Kolmakova, A. A.; Leonov, A. V.; Sevost'yanov, M. A.; Kolmakov, A. G.; Simakov, S. V.

    2017-05-01

    Nano- and micro-dimensional surface layers of silver and tantalum on flat and wire NiTi substrates by the method of magnetron sputtering in vacuum were produced. The structure and composition of the samples were determined using SEM and Auger spectroscopy. With an increase in the sputtering distance, the thickness of the surface layers decreases, and the thickness of the transition layer and the dependence of the thickness change as a whole depend on the nature of the sputtered substance.

  2. THE THICKNESS DEPENDENCE OF OXYGEN PERMEABILITY IN SOL-GEL DERIVED CGO-COFE2O4 THIN FILMS ON POROUS CERAMIC SUBSTRATES: A SPUTTERED BLOCKING LAYER FOR THICKNESS CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, K

    2009-01-08

    Mixed conductive oxides are a topic of interest for applications in oxygen separation membranes as well as use in producing hydrogen fuel through the partial oxidation of methane. The oxygen flux through the membrane is governed both by the oxygen ionic conductivity as well as the material's electronic conductivity; composite membranes like Ce{sub 0.8}Gd{sub 0.2}O{sub 2-{delta}} (CGO)-CoFe{sub 2}O{sub 4} (CFO) use gadolinium doped ceria oxides as the ionic conducting material combined with cobalt iron spinel which serves as the electronic conductor. In this study we employ {approx} 50 nm sputtered CeO{sub 2} layers on the surface of porous CGO ceramic substrates which serve as solution 'blocking' layers during the thin film fabrication process facilitating the control of film thickness. Films with thickness of {approx} 2 and 4 microns were prepared by depositing 40 and 95 separate sol-gel layers respectively. Oxygen flux measurements indicated that the permeation increased with decreasing membrane thickness; thin film membrane with thickness on the micron level showed flux values an order of magnitude greater (0.03 {micro}mol/cm{sup 2} s) at 800 C as compared to 1mm thick bulk ceramic membranes (0.003 {micro}mol/cm{sup 2}).

  3. Sputtered Layered Synthetic Microstruture (LSM) Dispersion Elements

    Science.gov (United States)

    Barbee, Troy W.

    1981-10-01

    The opportunities offered by engineered synthetic multilayer dispersion elements for x-rays have been recognized since the earliest days of x-ray diffraction analysis. In this paper, application of sputter deposition tehnology to the synthesis of Layered Synthetic Microstructure (LSM's) of sufficient quality or use as x-ray dispersion elements is discussed. It will be shown that high efficiency, controllble bandwidth dispersion elements, with d spacings varying from 15 Å to 180 Å, may be synthesized onto both mechanically stiff and flexible substrtes. Multilayer component materials include tungten, niobium, molybdenum, titanium, vanadium, and silicon layers separated by carbon layers. Experimental observations of peak reflectivity in first order, integrated reflectivity in first order, and diffraction performance at selected photon energies in the range, 100 to 15000 eV, will be reported and compared to theory. Emphasis is placed on results giving information concerning limiting structural characteristics of these LSM's. It will be shown that the observed behavior is in accord with theory, both kinematic and dynamic regimes being clearly observed. In addition, the mosaic spread of these LSM's is not detectable, indicatig that they are perfect structures. A consistent explanation of these experimental results indicates that roughness at the interfaces between constituent layers is the structural characteristic currently limiting diffracting behavior.

  4. Helium and hydrogen trapping in tungsten deposition layers formed by helium plasma sputtering

    International Nuclear Information System (INIS)

    Katayama, K.; Imaoka, K.; Okamura, T.; Nishikawa, M.

    2007-01-01

    Tungsten deposition layers were formed by helium plasma sputtering utilizing a capacitively coupled RF plasma. For comparison, hydrogen plasma was also used for the formation of the deposition layer. It was found that non-negligible amount of helium and hydrogen were trapped in the tungsten deposition layer formed helium plasma sputtering. It is considered that the hydrogen emitted from the plasma chamber wall by helium plasma discharge was trapped in the layer. Atomic ratio of helium to tungsten (He/W) in the layer was estimated to be 0.08. This value is not quite small compared with that of hydrogen in the tungsten deposition layer formed by hydrogen plasma sputtering. The release behavior of helium from the layer formed by helium plasma sputtering was similar to that of hydrogen from the layer formed by hydrogen plasma sputtering

  5. High-performance anode for Polymer Electrolyte Membrane Fuel Cells by multiple-layer Pt sputter deposition

    Science.gov (United States)

    Natarajan, Sadesh Kumar; Hamelin, Jean

    We investigate the sputtering deposition as a tool for preparing Polymer Electrolyte Membrane Fuel Cell (PEMFC) electrodes with improved performance and catalyst utilization. Anodes of PEMFC with ultra-low loading of Pt (0.05 mg cm -2) are developed by alternate sputtering of Pt and painting layers of carbon nanotube ink with Nafion directly on the gas diffusion layer. Sputter depositing alternate layers of Pt on carbon-Nafion layer (CNL) has increased the anode activity over single-layer Pt deposited anode due to improved porosity and the presence of Pt nanoparticles in the inner CNL. Also, we investigated the influence of Nafion content in the CNL. The optimal Nafion content giving less resistance and better performance in an anode is 29 wt.%. This is significantly lower than for standard MEA anodes, indicating sufficient interfacial contact between each CNL. We studied the anodes prepared with 50 wt.% Nafion, which revealed larger ohmic resistance and also, blocks the CNL pores reducing gas permeability. Excellent mass transfer and performance is obtained with three-layer Pt sputter deposited anode with CNL containing 29 wt.% of Nafion.

  6. Microstructures using RF sputtered PSG film as a sacrificial layer in ...

    Indian Academy of Sciences (India)

    are involved in the deposition process. Also RF sputtering is a low temperature process. The right combination of the structural and sacrificial layer material and sacrificial layer etching are some of the important issues in surface micro- machining technology (Ristic 1994). For fabricating large-sized free-standing structures, ...

  7. Early stages of growth of gold layers sputter deposited on glass and silicon substrates

    Czech Academy of Sciences Publication Activity Database

    Malinský, Petr; Slepička, P.; Hnatowicz, Vladimír; Švorčík, V.

    2012-01-01

    Roč. 7, č. 241 (2012), s. 1-7 ISSN 1931-7573 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : sputtering * gold layer * glass * silicon * RBS Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 2.524, year: 2012

  8. Microstructures using RF sputtered PSG film as a sacrificial layer in ...

    Indian Academy of Sciences (India)

    Abstract. In this paper, we explore RF magnetron sputtered Phosphor–silicate– glass (PSG) film as a sacrificial layer in surface micromachining technology. For this purpose, a 76mm diameter target of phosphorus-doped silicon dioxide was prepared by conventional solid-state reaction route using P2O5 and SiO2 powders.

  9. Fabrication of multi-electrode array platforms for neuronal interfacing with bi-layer lift-off resist sputter deposition

    International Nuclear Information System (INIS)

    Kim, Yong Hee; Kim, Gook Hwa; Baek, Nam Seob; Han, Young Hwan; Kim, Ah-Young; Chung, Myung-Ae; Jung, Sang-Don

    2013-01-01

    We report a bi-layer lift-off resist (LOR) technique in combination with sputter deposition of silicon dioxide (SiO 2 ) as a new passivation method in the fabrication of a multi-electrode array (MEA). Using the photo-insensitive LOR as a sacrificial bottom layer and the negative photoresist as a patterning top layer, and performing low-temperature sputter deposition of SiO 2 followed by lift-off, we could successfully fabricate damage-free indium-tin oxide (ITO) and Au MEA. The bi-layer LOR sputter deposition processed Au MEA showed an impedance value of 6 × 10 5 Ω (at 1 kHz), with good consistency over 60 electrodes. The passivation performance of the bi-layer LOR sputter-deposited SiO 2 was tested by electrodepositing Au nanoparticles (NPs) on the Au electrode, resulting in the well-confined and uniformly coated Au NPs. The bi-layer LOR sputter deposition processed ITO, Au, and Au NP-modified MEAs were evaluated and found to have a neuronal spike recording capability at a single unit level, confirming the validity of the bi-layer LOR sputter deposition as an effective passivation technique in fabrication of a MEA. These results suggest that the damage-free Au MEA fabricated with bi-layer LOR sputter deposition would be a viable platform for screening surface modification techniques that are available in neuronal interfacing. (technical note)

  10. Large-area few-layer MoS 2 deposited by sputtering

    KAUST Repository

    Huang, Jyun-Hong

    2016-06-06

    Direct magnetron sputtering of transition metal dichalcogenide targets is proposed as a new approach for depositing large-area two-dimensional layered materials. Bilayer to few-layer MoS2 deposited by magnetron sputtering followed by post-deposition annealing shows superior area scalability over 20 cm(2) and layer-by-layer controllability. High crystallinity of layered MoS2 was confirmed by Raman, photo-luminescence, and transmission electron microscopy analysis. The sputtering temperature and annealing ambience were found to play an important role in the film quality. The top-gate field-effect transistor by using the layered MoS2 channel shows typical n-type characteristics with a current on/off ratio of approximately 10(4). The relatively low mobility is attributed to the small grain size of 0.1-1 mu m with a trap charge density in grain boundaries of the order of 10(13) cm(-2).

  11. Tailoring of antibacterial Ag nanostructures on TiO2 nanotube layers by magnetron sputtering.

    Science.gov (United States)

    Uhm, Soo-Hyuk; Song, Doo-Hoon; Kwon, Jae-Sung; Lee, Sang-Bae; Han, Jeon-Geon; Kim, Kyoung-Nam

    2014-04-01

    To reduce the incidence of postsurgical bacterial infection that may cause implantation failure at the implant-bone interface, surface treatment of titanium implants with antibiotic materials such as silver (Ag) has been proposed. The purpose of this work was to create TiO2 nanotubes using plasma electrolytic oxidation (PEO), followed by formation of an antibacterial Ag nanostructure coating on the TiO2 nanotube layer using a magnetron sputtering system. PEO was performed on commercially pure Ti sheets. The Ag nanostructure was added onto the resulting TiO2 nanotube using magnetron sputtering at varying deposition rates. Field emission scanning electron microscopy and transmission electron microscopy were used to characterize the surface, and Ag content on the TiO2 nanotube layer was analyzed by X-ray diffraction and X-ray photoelectron spectroscopy. Scanning probe microscopy for surface roughness and contact angle measurement were used to indirectly confirm enhanced TiO2 nanotube hydrophilicity. Antibacterial activity of Ag ions in solution was determined by inductively coupled plasma mass spectrometry and antibacterial testing against Staphylococcus aureus (S. aureus). In vitro, TiO2 nanotubes coated with sputtered Ag resulted in significantly reduced S. aureus. Cell viability assays showed no toxicity for the lowest sputtering time group in the osteoblastic cell line MC3T3-E1. These results suggest that a multinanostructured layer with a biocompatible TiO2 nanotube and antimicrobial Ag coating is a promising biomaterial that can be tailored with magnetron sputtering for optimal performance. Copyright © 2013 Wiley Periodicals, Inc.

  12. Contribution to mechanical and crystallographic analysis of molyledenum layers prepared by magnetron cathode sputtering

    International Nuclear Information System (INIS)

    Bosland, P.

    1988-01-01

    Molybdenum coatings presenting different compression stresses are elaborated by magnetron cathode sputtering by varying the negative voltage of the substrate during deposition. Stress evolution is accompanied by crystal texture evolution and argon content incorporated in the layers. Crystallite orientation is explained by a phenomenon similar to canalisation observed in ion implantation. In a same deposit each component presents its own deformations different from neighbouring components [fr

  13. Direct Current Sputter Epitaxy of Heavily Doped p+ Layer for Monocrystalline Si Solar Cells

    Directory of Open Access Journals (Sweden)

    Wenchang Yeh

    2017-01-01

    Full Text Available Sputter epitaxy of p+ layer for fabrication of Si solar cells (SCs was demonstrated. Hall carrier concentration of p+ layer was 2.6 × 1020 cm−3 owing to cosputtering of B with Si at low temperature, which had enabled heavy and shallow p+ dope layer. p+nn+ SCs were fabricated and influence of p+ and n+ layers was investigated. Internal quantum efficiency (IQE of p+nn+ SCs was 95% at visible light and was larger than 60% at ultraviolet (UV light when the p+ layer was thinner than 30 nm. At near infrared (NIR, extra increment on IQE was achieved by rear n+ back surface field (BSF layer with a thickness thinner than 100 nm.

  14. Silicon oxide sacrificial layers deposited by pulsed-DC magnetron sputtering for MEMS applications

    Science.gov (United States)

    González-Castilla, Sheila; Olivares, Jimena; Clement, Marta; Vergara, Lucía; Pulido, Laura; Iborra, Enrique; Sangrador, Jesús

    2009-05-01

    Surface micromachining requires the use of easily-removable sacrificial layers fully compatible with all the materials and technological processes involved. Silicon dioxide films, thermally grown on silicon substrates or deposited by CVD, are commonly used as sacrificial layers in surface micromachining technologies, despite their low lateral etch rate in conventional fluorinate solutions. The development of silicon oxide layers with high etch rates poses a great technological challenge. In this work we have investigated the possibility of obtaining easily removable silicon oxide layers by pulsed-DC magnetron reactive sputtering. We have carried out a comprehensive study of the influence of the deposition parameters (total pressure and gas composition) on the composition, residual stress and lateral etch rate in fluorine wet solutions of the films. This study has allowed to determine the sputtering conditions to deposit, at very high rates (up to 0.1 μm/min), silicon oxide films with excellent characteristics for their use as sacrificial layers. Films with roughness around 5 nm rms, residual stress below 100 MPa and very high etch rate (up to 5 μm/min in the lateral directions), around 70 times greater than for thermal silicon oxide, have been achieved. The structural characteristics of these easily removable silicon oxide layers have been assessed by infrared spectroscopy and atomic force microscopy, which have revealed that the films exhibit some kind of porous structure, related to very specific sputter conditions. Finally, the viability of these films has been demonstrated by using them as sacrificial layer in the fabrication process of AlN-based microresonators.

  15. Hydrogen gas driven permeation through tungsten deposition layer formed by hydrogen plasma sputtering

    International Nuclear Information System (INIS)

    Uehara, Keiichiro; Katayama, Kazunari; Date, Hiroyuki; Fukada, Satoshi

    2015-01-01

    Highlights: • H permeation tests for W layer formed by H plasma sputtering are performed. • H permeation flux through W layer is larger than that through W bulk. • H diffusivity in W layer is smaller than that in W bulk. • The equilibrium H concentration in W layer is larger than that in W bulk. - Abstract: It is important to evaluate the influence of deposition layers formed on plasma facing wall on tritium permeation and tritium retention in the vessel of a fusion reactor from a viewpoint of safety. In this work, tungsten deposition layers having different thickness and porosity were formed on circular nickel plates by hydrogen RF plasma sputtering. Hydrogen permeation experiment was carried out at the temperature range from 250 °C to 500 °C and at hydrogen pressure range from 1013 Pa to 101,300 Pa. The hydrogen permeation flux through the nickel plate with tungsten deposition layer was significantly smaller than that through a bare nickel plate. This indicates that a rate-controlling step in hydrogen permeation was not permeation through the nickel plate but permeation though the deposition layer. The pressure dependence on the permeation flux differed by temperature. Hydrogen permeation flux through tungsten deposition layer is larger than that through tungsten bulk. From analysis of the permeation curves, it was indicated that hydrogen diffusivity in tungsten deposition layer is smaller than that in tungsten bulk and the equilibrium hydrogen concentration in tungsten deposition layer is enormously larger than that in tungsten bulk at same hydrogen pressure.

  16. Block copolymer/homopolymer dual-layer hollow fiber membranes

    KAUST Repository

    Hilke, Roland

    2014-12-01

    We manufactured the first time block copolymer dual-layer hollow fiber membranes and dual layer flat sheet membranes manufactured by double solution casting and phase inversion in water. The support porous layer was based on polystyrene and the selective layer with isopores was formed by micelle assembly of polystyrene-. b-poly-4-vinyl pyridine. The dual layers had an excellent interfacial adhesion and pore interconnectivity. The dual membranes showed pH response behavior like single layer block copolymer membranes with a low flux for pH values less than 3, a fast increase between pH4 and pH6 and a constant high flux level for pH values above 7. The dry/wet spinning process was optimized to produce dual layer hollow fiber membranes with polystyrene internal support layer and a shell block copolymer selective layer.

  17. Room-temperature processed tin oxide thin film as effective hole blocking layer for planar perovskite solar cells

    Science.gov (United States)

    Tao, Hong; Ma, Zhibin; Yang, Guang; Wang, Haoning; Long, Hao; Zhao, Hongyang; Qin, Pingli; Fang, Guojia

    2018-03-01

    Tin oxide (SnO2) film with high mobility and good transmittance has been reported as a promising semiconductor material for high performance perovskite solar cells (PSCs). In this study, ultrathin SnO2 film synthesized by radio frequency magnetron sputtering (RFMS) method at room temperature was employed as hole blocking layer for planar PSCs. The room-temperature sputtered SnO2 film not only shows favourable energy band structure but also improves the surface topography of fluorine doped SnO2 (FTO) substrate and perovskite (CH3NH3PbI3) layer. Thus, this SnO2 hole blocking layer can efficiently promote electron transport and suppress carrier recombination. Furthermore, the best efficiency of 13.68% was obtained for planar PSC with SnO2 hole blocking layer prepared at room temperature. This research highlights the room-temperature preparation process of hole blocking layer in PSC and has a certain reference significance for the usage of flexible and low-cost substrates.

  18. Development of mid-frequency AC reactive magnetron sputtering for fast deposition of Y2O3 buffer layers

    Science.gov (United States)

    Xiong, Jie; Xia, Yudong; Xue, Yan; Zhang, Fei; Guo, Pei; Zhao, Xiaohui; Tao, Bowan

    2014-02-01

    A reel-to-reel magnetron sputtering system with mid-frequency alternating current (AC) power supply was used to deposit double-sided Y2O3 seed layer on biaxially textured Ni-5 at.%W tape for YBa2Cu3O7-δ coated conductors. A reactive sputtering process was carried out using two opposite symmetrical sputtering guns with metallic yttrium targets and water vapor for oxidizing the sputtered metallic atoms. The voltage control mode of the power supply was used and the influence of the cathode voltage and ArH2 pressure were systematically investigated. Subsequently yttrium-stabilized zirconia (YSZ) barrier and CeO2 cap layers were deposited on the Y2O3 buffered substrates in sequence, indicating high quality and uniform double-sided structure and surface morphology of such the architecture.

  19. Molecular dynamics simulation of chemical sputtering of hydrogen atom on layer structured graphite

    International Nuclear Information System (INIS)

    Ito, A.; Wang, Y.; Irle, S.; Morokuma, K.; Nakamura, H.

    2008-10-01

    Chemical sputtering of hydrogen atom on graphite was simulated using molecular dynamics. Especially, the layer structure of the graphite was maintained by interlayer intermolecular interaction. Three kinds of graphite surfaces, flat (0 0 0 1) surface, armchair (1 1 2-bar 0) surface and zigzag (1 0 1-bar 0) surface, are dealt with as targets of hydrogen atom bombardment. In the case of the flat surface, graphene layers were peeled off one by one and yielded molecules had chain structures. On the other hand, C 2 H 2 and H 2 are dominant yielded molecules on the armchair and zigzag surfaces, respectively. In addition, the interaction of a single hydrogen isotope on a single graphene is investigated. Adsorption, reflection and penetration rates are obtained as functions of incident energy and explain hydrogen retention on layered graphite. (author)

  20. Comparative studies on damages to organic layer during the deposition of ITO films by various sputtering methods

    Science.gov (United States)

    Lei, Hao; Wang, Meihan; Hoshi, Yoichi; Uchida, Takayuki; Kobayashi, Shinichi; Sawada, Yutaka

    2013-11-01

    Aluminum (III) bis(2-methyl-8-quninolinato)-4-phenylphenolate (BAlq) was respectively bombarded and irradiated by Ar ions, oxygen ions, electron beam and ultraviolet light to confirm damages during the sputter-deposition of transparent conductive oxide (TCO) on organic layer. The degree of damage was evaluated by the photoluminescence (PL) spectra of BAlq. The results confirmed the oxygen ions led to a larger damage and were thought to play the double roles of bombardment to organic layer and reaction with organic layer as well. The comparative studies on PL spectra of BAlq after the deposition of TCO films by various sputtering systems, such as conventional magnetron sputtering (MS), low voltage sputtering (LVS) and kinetic-energy-control-deposition (KECD) system, facing target sputtering (FTS) were performed. Relative to MS, LVS and KECD system, FTS can completely suppress the bombardment of the secondary electrons and oxygen negative ions, and keep a higher deposition rate simultaneously, thus it is a good solution to attain a low-damage sputter-deposition.

  1. Crystallization study of amorphous sputtered NiTi bi-layer thin film

    Energy Technology Data Exchange (ETDEWEB)

    Mohri, Maryam, E-mail: mmohri@ut.ac.ir [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Karlsruhe Institute of Technology, Institute of Nanotechnology, 76021 Karlsruhe (Germany); Nili-Ahmadabadi, Mahmoud [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Center of Excellence for High Performance Materials, University of Tehran, Tehran (Iran, Islamic Republic of); Chakravadhanula, Venkata Sai Kiran [Karlsruhe Institute of Technology, Institute of Nanotechnology, 76021 Karlsruhe (Germany)

    2015-05-15

    The crystallization of Ni-rich/NiTiCu bi-layer thin film deposited by magnetron sputtering from two separate alloy targets was investigated. To achieve the shape memory effect, the NiTi thin films deposited at room temperature with amorphous structure were annealed at 773 K for 15, 30, and 60 min for crystallization. Characterization of the films was carried out by differential scanning calorimetry to indicate the crystallization temperature, grazing incidence X-ray diffraction to identify the phase structures, atomic force microscopy to evaluate surface morphology, scanning transmission electron microscopy to study the cross section of the thin films. The results show that the structure of the annealed thin films strongly depends on the temperature and time of the annealing. Crystalline grains nucleated first at the surface and then grew inward to form columnar grains. Furthermore, the crystallization behavior was markedly affected by composition variations. - Highlights: • A developed bi-layer Ni45TiCu5/Ni50.8Ti was deposited on Si substrate and crystallized. • During crystallization, The Ni{sub 45}TiCu{sub 5} layer is thermally less stable than the Ni-rich layer. • The activation energy is 302 and 464 kJ/mol for Cu-rich and Ni-rich layer in bi-layer, respectively.

  2. Suppression of sputtering of nickel by coverage with self-sustaining thin segregated carbon layers

    Energy Technology Data Exchange (ETDEWEB)

    Morita, K.; Tsuchiya, T.; Hayashibara, M.; Itoh, N. (Nagoya Univ. (Japan). Dept. of Crystalline Materials Science)

    1983-05-01

    Sputtering of two-layered films composed of nickel ( proportional 5000 A) and nickel carbine ( proportional1500 A) at 600/sup 0/C by 5 keV Ar/sup +/ bombardment on the nickel side has been studied using Rutherford backscattering of 1.3 MeV H/sup +/ ions. It is found that the removal rate of nickel atoms from specimens is dependent on ion current density and that the removal rate of nickel atoms is very much smaller than that of carbon atoms when the ion current density is low. During ion bombardment at a low current density carbon segregation by a thickness of nearly two monolayers is observed at the nickel surface. Thus suppression of the removal rate of nickel atoms is ascribed to coverage of the nickel surface with segregated carbon atoms which are continuously supplied by diffusion through the nickel film from the carbide layer.

  3. Polymer supported ZIF-8 membranes by conversion of sputtered zinc oxide layers

    KAUST Repository

    Neelakanda, Pradeep

    2015-09-05

    ZIF-8 composite membranes were synthesized at room temperature from aqueous solution by a double-zinc-source method on polyacrylonitrile (PAN) porous supports. The support was coated with zinc oxide (ZnO) by magnetron sputtering prior to ZIF-8 growth to improve the nucleation as well as the adhesion between the ZIF-8 layer and support. By this method, we were able to grow a continuous, dense, very thin (900 nm) and defect free ZIF-8 layer on a polymeric support. The developed ZIF-8 membranes had a gas permeance of 1.23 x 10-7 mol m-2 sec-1 Pa-1 for hydrogen and a selectivity of 26 for hydrogen/propane gases which is 5 times higher than the Knudsen selectivity. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were done to characterize the membranes.

  4. Hydrogen and helium trapping in tungsten deposition layers formed by RF plasma sputtering

    International Nuclear Information System (INIS)

    Kazunari Katayama; Kazumi Imaoka; Takayuki Okamura; Masabumi Nishikawa

    2006-01-01

    Understanding of tritium behavior in plasma facing materials is an important issue for fusion reactor from viewpoints of fuel control and radiation safety. Tungsten is used as a plasma facing material in the divertor region of ITER. However, investigation of hydrogen isotope behavior in tungsten deposition layer is not sufficient so far. It is also necessary to evaluate an effect of helium on a formation of deposition layer and an accumulation of hydrogen isotopes because helium generated by fusion reaction exists in fusion plasma. In this study, tungsten deposition layers were formed by sputtering method using hydrogen and helium RF plasma. An erosion rate and a deposition rate of tungsten were estimated by weight measurement. Hydrogen and helium retention were investigated by thermal desorption method. Tungsten deposition was performed using a capacitively-coupled RF plasma device equipped with parallel-plate electrodes. A tungsten target was mounted on one electrode which is supplied with RF power at 200 W. Tungsten substrates were mounted on the other electrode which is at ground potential. The plasma discharge was continued for 120 hours where pressure of hydrogen or helium was controlled to be 10 Pa. The amounts of hydrogen and helium released from deposition layers was quantified by a gas chromatograph. The erosion rate of target tungsten under helium plasma was estimated to be 1.8 times larger than that under hydrogen plasma. The deposition rate on tungsten substrate under helium plasma was estimated to be 4.1 times larger than that under hydrogen plasma. Atomic ratio of hydrogen to tungsten in a deposition layer formed by hydrogen plasma was estimated to be 0.17 by heating to 600 o C. From a deposition layer formed by helium plasma, not only helium but also hydrogen was released by heating to 500 o C. Atomic ratios of helium and hydrogen to tungsten were estimated to be 0.080 and 0.075, respectively. The trapped hydrogen is probably impurity hydrogen

  5. Optimation of Sputtering Process Parameters on the Deposition of Nitride Titanium Thin Layer on Aluminum Alloys

    International Nuclear Information System (INIS)

    Tjipto Sujitno; Agus Santoso; Wiryoadi; Sayono; Bambang Siswanto; Lely Susita RM

    2002-01-01

    Research on the optimization of sputtering process parameters on the deposition of nitride titanium thin layer on aluminum alloys has been carried out. The aim of this research is to get the optimum conditions of the process parameters. The parameters of the process are ratio of sputter gas (Ar) and dopant (Nitrogen) gas, time of the process (t), temperature (T), electrode distance, electrode voltage and vacuum conditions of the process. In this experiment the electrode distance and electrode voltage are constants i.e.: 4 cm, 1.5 kV and 2.0 x 10 -1 torr, respectively. To examine the results, it was characterized its hardness, wear and corrosion resistance. It's found that optimum conditions was achieved at the ratio of Ar:N 2 = 5:7, t = 3 hours, T= 100 o C and vacuum conditions 2 x 10 -2 torr. At the optimum conditions, the hardness increases from 120.33 KHN to 149.59 KHN or there is an increasing in hardness in order of 24.32 %, the wear resistance increases from 1 x 10 -4 g/minutes to 6 x 10 -5 g/minutes or there is an increasing in wear resistance in order of 40.00 %, and the corrosion resistance in diluted sea water 1000 times media increases from 6.22 mpy to 0.68 mpy or there is an increasing in corrosion resistance in order of 811.76 %. (author)

  6. Properties of Erbium and Ytterbium Doped Gallium Nitride Layers Fabricated by Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    V. Prajzler

    2006-01-01

    Full Text Available We report about some properties of erbium and erbium/ytterbium doped gallium nitride (GaN layers fabricated by magnetron sputtering onsilicon, quartz and Corning glass substrates. For fabricating GaN layers two types of targets were used - gallium in a stainless steel cup anda Ga2O3 target. Deposition was carried out in the Ar+N2 gas mixture. For erbium and ytterbium doping into GaN layers, erbium metallicpowder and ytterbium powder or Er2O3 and Yb2O3 pellets were laid on the top of the target. The samples were characterized by X-raydiffraction (XRD, photoluminescence spectra and nuclear analytical methods. While the use of a metallic gallium target ensured thedeposition of well-developed polycrystalline layers, the use of gallium oxide target provided GaN films with poorly developed crystals. Bothapproaches enabled doping with erbium and ytterbium ions during deposition, and typical emission at 1 530 nm due to the Er3+ intra-4f 4I13/2 → 4I15/2 transition was observed.

  7. Silicon transport in sputter-deposited tantalum layers grown under ion bombardment

    International Nuclear Information System (INIS)

    Gallais, P.; Hantzpergue, J.J.; Remy, J.C.; Roptin, D.

    1988-01-01

    Tantalum was sputter deposited on (111) Si substrate under low-energy ion bombardment in order to study the effects of the ion energy on the silicon transport into the Ta layer. The Si substrate was heated up to 500 0 C during growth. For ion energies up to 180 eV silicon is not transported into tantalum and the growth temperature has no effect. An ion bombardment energy of 280 eV enhances the transport of silicon throughout the tantalum layer. Growth temperatures up to 300 0 C have no effect on the silicon transport which is mainly enhanced by the ion bombardment. For growth temperatures between 300 and 500 0 C, the silicon transport is also enhanced by the thermal diffusion. The experimental depth distribution of silicon is similar to the theoretical depth distribution calculated for the case of an interdiffusion. The ion-enhanced process of silicon transport is characterized by an activation energy of 0.4 eV. Silicon into the layers as-grown at 500 0 C is in both states, amorphous silicide and microcrystalline cubic silicon

  8. Sputter-induced formation of an electron accumulation layer in In0.52Al0.48As

    Science.gov (United States)

    Maslar, J. E.; Bohn, P. W.; Agarwala, S.; Adesida, I.; Caneau, C.; Bhat, R.

    1994-06-01

    Ar-sputtering of In0.52Al0.48As was investigated with room-temperature Raman and photoluminescence spectroscopy. A clear increase of carrier density in the near-surface region was observed in the Raman spectra. The PL intensity was found to depend in a complex way on plasma self-bias potential, incident laser irradiance, and InAlAs doping level, indicating that the recombination mechanisms dominating the PL response differ with changing experimental conditions. The observed trends can be explained by sputter-induced formation of an electron accumulation layer in the near-surface region.

  9. Carbon and tungsten effect on characteristics of sputtered and re-deposited beryllium target layers under deuteron bombardment

    International Nuclear Information System (INIS)

    Danelyan, L.S.; Gureev, V.M.; Elistratov, N.G.

    2004-01-01

    The behavior of the plasma facing Be-elements in the International Thermonuclear Experimental Reactor ITER will be affected by the re-deposition of other eroded plasma facing materials. The effect of carbon- and tungsten-additions on the microstructure, chemical composition and hydrogen isotope accumulation in the sputtered and re-deposited layers of beryllium TGP-56 at its interaction with 200 - 300 eV hydrogen isotope ions was studied in the MAGRAS facility equipped with a magnetron sputtering system. (author)

  10. Method for sputtering a PIN amorphous silicon semi-conductor device having partially crystallized P and N-layers

    Science.gov (United States)

    Moustakas, Theodore D.; Maruska, H. Paul

    1985-07-09

    A high efficiency amorphous silicon PIN semiconductor device having partially crystallized (microcrystalline) P and N layers is constructed by the sequential sputtering of N, I and P layers and at least one semi-transparent ohmic electrode. The method of construction produces a PIN device, exhibiting enhanced electrical and optical properties, improved physical integrity, and facilitates the preparation in a singular vacuum system and vacuum pump down procedure.

  11. Study of Sb/SnO2 bi-layer films prepared by ion beam sputtering deposition technique

    International Nuclear Information System (INIS)

    Wang, Chun-Min; Huang, Chun-Chieh; Kuo, Jui-Chao; Huang, Jow-Lay

    2014-01-01

    In the present work, bi-layer thin films of Sb/SnO 2 were produced on unheated glass substrates using ion beam sputtering (IBS) technique without post annealing treatment. The thickness of Sb layers was varied from 2 to 10 nm and the Sb layers were deposited on SnO 2 layers having thicknesses of 40 nm to 115 nm. The effect of thickness was studied on the morphological, electrical and optical properties. The Sb/SnO 2 bi-layer resulted in lowering the electrical resistivity as well as reducing the optical transmittance. However, the optical and electrical properties of the bi-layer films were mainly influenced by the thickness of Sb layers due to progressive transfer in structures from aggregate to continuous films. The bi-layer films show the electrical resistivity of 1.4 × 10 −3 Ω cm and an optical transmittance of 26% for Sb film having 10 nm thickness. - Highlights: • Bi-layer Sb/SnO 2 structures were synthesized by ion beam sputtering (IBS) technique. • The 6 nm-thick Sb film is a transition region in this study. • The conductivity of the bi-layer films is increased as Sb thickness increases. • The transmittance of the bi-layer films is decreased as Sb thickness increases

  12. Microstructural characterization of chemical bath deposited and sputtered Zn(O,S) buffer layers

    International Nuclear Information System (INIS)

    Gautron, E.; Buffière, M.; Harel, S.; Assmann, L.; Arzel, L.; Brohan, L.; Kessler, J.; Barreau, N.

    2013-01-01

    The present work aims at investigating the microstructure of Zn(O,S) buffer layers relative to their deposition route, namely either chemical bath deposition (CBD) or RF co-sputtering process (PVD) under pure Ar. The core of the study consists of cross-sectional transmission electron microscopy (TEM) characterization of the differently grown Zn(O,S) thin films on co-evaporated Cu(In,Ga)Se 2 (CIGSe) absorbers. It shows that the morphology of Zn(O,S) layer deposited on CIGSe using CBD process is made of a thin layer of well oriented ZnS sphalerite-(111) and/or ZnS wurtzite-(0002) planes parallel to CIGSe chalcopyrite-(112) planes at the interface with CIGSe followed by misoriented nanometer-sized ZnS crystallites in an amorphous phase. As far as (PVD)Zn(O,S) is concerned, the TEM analyses reveal two different microstructures depending on the S-content in the films: for [S] / ([O] + [S]) = 0.6, the buffer layer is made of ZnO zincite and ZnS wurtzite crystallites grown nearly coherently to each other, with (0002) planes nearly parallel with CIGSe-(112) planes, while for [S] / ([O] + [S]) = 0.3, it is made of ZnO zincite type crystals with O atoms substituted by S atoms, with (0002) planes perfectly aligned with CIGSe-(112) planes. Such microstructural differences can explain why photovoltaic performances are dependent on the Zn(O,S) buffer layer deposition route. - Highlights: ► Zn(O,S) layers were grown by chemical bath (CBD) or physical vapor (PVD) deposition. ► For CBD, a 3 nm ZnS layer is followed by ZnS nano-crystallites in an amorphous phase. ► For PVD with [S] / ([O] + [S]) = 0.3, the layer has a Zn(O,S) zincite structure. ► For PVD with [S] / ([O] + [S]) = 0.6, ZnS wurtzite and ZnO zincite phases are mixed

  13. Sputter fabricated Nb-oxide-Nb josephson junctions incorporating post-oxidation noble metal layers

    International Nuclear Information System (INIS)

    Bain, R.J.P.; Donaldson, G.B.

    1985-01-01

    We present an extension, involving other metals, of the work of Hawkins and Clarke, who found that a thin layer of copper prevented the formation of the superconductive shorts which are an inevitable consequence of sputtering niobium counter-electrodes directly on top of niobium oxide. We find gold to be the most satisfactory, and that 0.3 nm is sufficient to guarantee short-free junctions of excellent electrical and mechanical stability, though high excess conductance means they are best suited to shunted-junction applications, as in SQUIDs. We present results for critical current dependence on oxide thickness and on gold thickness. Our data shows that thermal oxide growth is described by the Cabrera-Mott mechanism. We show that the protective effect of the gold layer can be understood in terms of the electro-chemistry of the Nb-oxide-Au structure, and that the reduced quasi-particle resistance of the junctions relative to goldfree junctions with evaporated counterelectrodes can be explained in terms of barrier shape modification, and not by proximity effect mechanisms. The performance of a DC SQUID based on these junctions is described

  14. Improvements in the properties of NbN layers through the presence of small amounts of aluminum during sputtering

    International Nuclear Information System (INIS)

    Haase, E.L.; Ruzicka, J.

    1988-09-01

    Pure phase B1 NbN layers could be sputtered in our laboratory only with a maximum T c of 15.9 K and a residual resistance ratio RRR of c of up to 16.7 K invariably had a large fraction of hexagonal foreign phase. If under similar conditions one sputters layers in the presence of small amounts of Al, one obtains pure B1 phase NbN layers with a maximum T c of 16.9 K. The RRR rises to values of up to 1.16. The specific resistance drops from typical values of around 400 μΩcm to values as low as 73 μΩcm. The width of the X-ray lines drops occasionally, indicating increased grain size. Al acts like a catalyst, being substituted with less than 0.03 at% for a high T c layer. When Al is substituted for Nb in detectable quantities both T c and the lattice parameter drop. To verify the above results the experiment was repeated in a magnetron rather than a RF sputter system with similar outcome. (orig.)

  15. Shell Layer Thickness-Dependent Photocatalytic Activity of Sputtering Synthesized Hexagonally Structured ZnO-ZnS Composite Nanorods.

    Science.gov (United States)

    Liang, Yuan-Chang; Lo, Ya-Ru; Wang, Chein-Chung; Xu, Nian-Cih

    2018-01-07

    ZnO-ZnS core-shell nanorods are synthesized by combining the hydrothermal method and vacuum sputtering. The core-shell nanorods with variable ZnS shell thickness (7-46 nm) are synthesized by varying ZnS sputtering duration. Structural analyses demonstrated that the as-grown ZnS shell layers are well crystallized with preferring growth direction of ZnS (002). The sputtering-assisted synthesized ZnO-ZnS core-shell nanorods are in a wurtzite structure. Moreover, photoluminance spectral analysis indicated that the introduction of a ZnS shell layer improved the photoexcited electron and hole separation efficiency of the ZnO nanorods. A strong correlation between effective charge separation and the shell thickness aids the photocatalytic behavior of the nanorods and improves their photoresponsive nature. The results of comparative degradation efficiency toward methylene blue showed that the ZnO-ZnS nanorods with the shell thickness of approximately 17 nm have the highest photocatalytic performance than the ZnO-ZnS nanorods with other shell layer thicknesses. The highly reusable catalytic efficiency and superior photocatalytic performance of the ZnO-ZnS nanorods with 17 nm-thick ZnS shell layer supports their potential for environmental applications.

  16. Deposition and characterization of layer-by-layer sputtered AgGaSe{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Karaagac, H. [Department of Physics, Middle East Technical University, 06531 Ankara (Turkey); Parlak, M., E-mail: parlak@metu.edu.tr [Department of Physics, Middle East Technical University, 06531 Ankara (Turkey)

    2011-04-15

    Sputtering technique has been used for the deposition of AgGaSe{sub 2} thin films onto soda-lime glass substrates using sequential layer-by-layer deposition of GaSe and Ag thin films. The analysis of energy dispersive analysis of X-ray (EDXA) indicated a Ga-rich composition for as-grown samples and there was a pronounce effect of post-annealing on chemical composition of AgGaSe{sub 2} thin film. X-ray diffraction (XRD) measurements revealed that Ag metallic phase exists in the amorphous AgGaSe{sub 2} structure up to annealing temperature 450 deg. C and then the structure turned to the single phase AgGaSe{sub 2} with the preferred orientation along (1 1 2) direction with the annealing temperature at 600 deg. C. The surface morphology of the samples was analyzed by scanning electron microscopy (SEM) measurements. The structural parameters related to chalcopyrite compounds have been calculated. Optical properties of AgGaSe{sub 2} thin films were studied by carrying out transmittance and reflectance measurements in the wavelength range of 325-1100 nm at room temperature. The absorption coefficient and the band gap values for as-grown and annealed samples were evaluated as 1.55 and 1.77 eV, respectively. The crystal-field and spin-orbit splitting levels were resolved. These levels (2.03 and 2.30 eV) were also detected from the photoresponse measurements almost at the same energy values. As a result of the temperature dependent resistivity and mobility measurements in the temperature range of 100-430 K, it was found that the decrease in mobility and the increase in carrier concentration following to the increasing annealing temperature attributed to the structural defects (tetragonal distortion, vacancies and interstitials).

  17. Blocking layer modeling for temperature analysis of electron transfer ...

    African Journals Online (AJOL)

    In this article, we simulate thermal effects on the electron transfer rate from three quantum dots CdSe, CdS and CdTe to three metal oxides TiO2, SnO2 and ZnO2 in the presence of four blocking layers ZnS, ZnO, TiO2 and Al2O3, in a porous quantum dot sensitized solar cell (QDSSC) structure, using Marcus theory.

  18. Improvement of InN layers deposited on Si(111) by RF sputtering using a low-growth-rate InN buffer layer

    International Nuclear Information System (INIS)

    Valdueza-Felip, S.; Ibáñez, J.; Monroy, E.; González-Herráez, M.; Artús, L.; Naranjo, F.B.

    2012-01-01

    We investigate the influence of a low-growth-rate InN buffer layer on structural and optical properties of wurtzite nanocrystalline InN films deposited on Si(111) substrates by reactive radio-frequency sputtering. The deposition conditions of the InN buffer layer were optimized in terms of morphological and structural quality, leading to films with surface root-mean-square roughness of ∼ 1 nm under low-growth-rate conditions (60 nm/h). The use of the developed InN buffer layer improves the crystalline quality of the subsequent InN thick films deposited at high growth rate (180 nm/h), as confirmed by the narrowing of X-ray diffraction peaks and the increase of the average grain size of the layers. This improvement of the structural quality is further confirmed by Raman scattering spectroscopy measurements. Room temperature PL emission peaking at ∼ 1.58 eV is observed for InN samples grown with the developed buffer layer. The crystal and optical quality obtained for InN films grown on Si(111) using the low-growth-rate InN buffer layer become comparable to high-quality InN films deposited directly on GaN templates by RF sputtering. - Highlights: ► Improved RF-sputtered InN films on Si(111) using a low-growth-rate InN buffer layer. ► Enhanced structural quality confirmed by X-ray diffraction and Raman measurements. ► Room-temperature photoluminescence emission at 1.58 eV. ► InN films deposited with buffer layer on Si comparable to InN LAYERS on GaN templates.

  19. Natural and gamma radiation-induced conduction of silica and metaphosphate glass layers deposed by radiofrequency cathode sputtering

    International Nuclear Information System (INIS)

    Serra, Andre

    1977-01-01

    We present a study of natural and 60 Co induced conductions in radiofrequency sputtering deposed layers. Capacimetry and electronic microscopy observations permit a knowledge of the physical characteristics, mainly: homogeneity and thickness of these layers. A study of the natural current permit to characterise electrically the deposited films, the electrode and bulk insulator effects. In induced conduction, the behaviour of currents as a function of dose rate is interpreted in terms of ROSE'S and FOWLER'S photoconductivity theories. Induced currents versus applied fields are observed and compared with these obtained in the case of dielectric liquids and glasses. (author) [fr

  20. Improved performance of GaN based light emitting diodes with ex-situ sputtered AlN nucleation layers

    Directory of Open Access Journals (Sweden)

    Shuo-Wei Chen

    2016-04-01

    Full Text Available The crystal quality, electrical and optical properties of GaN based light emitting diodes (LEDs with ex-situ sputtered physical vapor deposition (PVD aluminum nitride (AlN nucleation layers were investigated. It was found that the crystal quality in terms of defect density and x-ray diffraction linewidth was greatly improved in comparison to LEDs with in-situ low temperature GaN nucleation layer. The light output power was 3.7% increased and the reverse bias voltage of leakage current was twice on LEDs with ex-situ PVD AlN nucleation layers. However, larger compressive strain was discovered in LEDs with ex-situ PVD AlN nucleation layers. The study shows the potential and constrain in applying ex-situ PVD AlN nucleation layers to fabricate high quality GaN crystals in various optoelectronics.

  1. Releasing of Sputtered Au Film by Dissolving Sacrificial Layer and Its Self-Standing on Perforated Substrate

    Science.gov (United States)

    Miyamoto, Yu; Fujii, Yuma; Yamano, Masafumi; Harigai, Toru; Suda, Yoshiyuki; Takikawa, Hirofumi; Nishiuchi, Mamiko; Sakaki, Hironao; Kondo, Kiminori

    2015-09-01

    Free-standing thin films such as diamond-like carbon (DLC) and gold (Au) have been attracted increasing interests as film targets used in the laser-driven ion acceleration experiment. One of the methods to make the free-standing thin film is to use a soluble sacrifice layer. In this study, the fabrication technique of self-standing Au thin film is presented. Gelatin, oblate, silk fibroin, and NaCl were examined as a. Au thin films were deposited by DC plasma sputtering on sacrifice layers. The gelatin and oblate were used as the sacrificial layer and the supporting substrate. Silk fibroin was coated on glass substrates by a spin coater. The NaCl sacrificial layers were deposited on flat Si substrates by the vacuum vapor deposition system. Sputtered Au thin films were released by immersing the substrates in purified water. Self-standing Au thin films were fabricated by scooping up the released Au thin film on a perforated substrate. The highest quality of the self-standing Au thin film was achieved by using NaCl sacrificial layer. This work was supported by JSPS KAKENHI Grant-in-Aid for Scientific Research and Toukai Foundation for Technology.

  2. Properties of Erbium Doped Hydrogenated Amorphous Carbon Layers Fabricated by Sputtering and Plasma Assisted Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    V. Prajzler

    2008-01-01

    Full Text Available We report about properties of carbon layers doped with Er3+ ions fabricated by Plasma Assisted Chemical Vapor Deposition (PACVD and by sputtering on silicon or glass substrates. The structure of the samples was characterized by X-ray diffraction and their composition was determined by Rutherford Backscattering Spectroscopy and Elastic Recoil Detection Analysis. The Absorbance spectrum was taken in the spectral range from 400 nm to 600 nm. Photoluminescence spectra were obtained using two types of Ar laser (λex=514.5 nm, lex=488 nm and also using a semiconductor laser (λex=980 nm. Samples fabricated by magnetron sputtering exhibited typical emission at 1530 nm when pumped at 514.5 nm. 

  3. Sputtering and coloration process in LiF thin layers induced by MeV ion bombardment

    Science.gov (United States)

    Cremona, M.; Pereira, J. A. M.; Mauricio, M. H. P.; Carmo, L. C. Scavarda Do; Somma, F.

    Beams of 2.0 MeV nitrogen ions, produced by a Van de Graaff generator, were used in order to create point defects in polycrystalline LiF thin films. The radiation effects were examined by optical absorption, RBS, PDMS and XPS methods. The concentration of the produced F-centers exhibits a saturation behavior, but decreases for doses higher than ˜ 1 × 1016 cm-2. A fluorine sputtering yield Y ˜ 3 was determined by using RBS. Moreover, XPS and PDMS techniques detected surface Li enrichment as a result of the ion bombardment. All these results denote the relevance of the sputtering in the de-coloration process of LiF thin layers.

  4. Giant magnetoimpedance effect in sputtered single layered NiFe film and meander NiFe/Cu/NiFe film

    International Nuclear Information System (INIS)

    Chen, L.; Zhou, Y.; Lei, C.; Zhou, Z.M.; Ding, W.

    2010-01-01

    Giant magnetoimpedance (GMI) effect on NiFe thin film is very promising due to its application in developing the magnetic field sensors with highly sensitivity and low cost. In this paper, the single layered NiFe thin film and NiFe/Cu/NiFe thin film with a meander structure are prepared by the MEMS technology. The influences of sputtering parameters, film structure and conductor layer width on GMI effect in NiFe single layer and meander NiFe/Cu/NiFe film are investigated. Maximum of the GMI ratio in single layer and sandwich film is 5% and 64%, respectively. The results obtained are useful for developing the high-performance magnetic sensors based on NiFe thin film.

  5. Preferential orientation growth of ITO thin film on quartz substrate with ZnO buffer layer by magnetron sputtering technique

    Science.gov (United States)

    Du, Wenhan; Yang, Jingjing; Xiong, Chao; Zhao, Yu; Zhu, Xifang

    2017-07-01

    In order to improve the photoelectric transformation efficiency of thin-film solar cells, one plausible method was to improve the transparent conductive oxides (TCO) material property. In-doped tin oxide (ITO) was an important TCO material which was used as a front contact layer in thin-film solar cell. Using magnetron sputtering deposition technique, we prepared preferential orientation ITO thin films on quartz substrate. XRD and SEM measurements were used to characterize the crystalline structure and morphology of ITO thin films. The key step was adding a ZnO thin film buffer layer before ITO deposition. ZnO thin film buffer layer increases the nucleation center numbers and results in the (222) preferential orientation growth of ITO thin films.

  6. Microstructures using RF sputtered PSG film as a sacrificial layer in ...

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana; Volume 34; Issue 4. Microstructures using RF sputtered PSG film ... Bhatt1 Sudhir Chandra1 Chatar Singh2. Centre for Applied Research in Electronics (CARE), Indian Institute of Technology Delhi, New Delhi 110 016; Textile Technology, Indian Institute of Technology Delhi, New Delhi 110 016 ...

  7. Deuterium retention in the carbon co-deposition layers deposited by magnetron sputtering in D2/He atmosphere

    Science.gov (United States)

    Tang, X. H.; Shi, L. Q.; Qi, Q.; Zhang, B.; Zhang, W. Y.; Hu, J. S.; O'Connor, D. J.; King, B.

    2013-05-01

    Carbon was deposited on Si and W substrates using a D2/He plasma in a radio frequency magnetron sputtering system. The deposited layers were examined with ion beam analysis (IBA), Raman spectra analysis (RS) and scanning electron microscopy (SEM). The growth rate of the layers deposited at 2.5 Pa total pressure and 300 K decreased with increasing He fraction in the D2/He gas mixture. The deuterium concentration in the layers deposited on the Si substrate increased from 14% to 28% when the flow rate of the He gas relative to the D2 gas was varied from 0.125 to 0.5, but the deuterium concentration in the layers on a W substrate decreased from 24% to 14%. Deuterium or helium retention and the layer thickness all significantly decreased when the substrate temperature was increased from 423 K to 773 K. Raman analysis showed that the deposited layers were amorphous deuterated-carbon layers (named a-C: D layer) and the extent of bond disorder increased dramatically with the increasing helium content in the film. Blisters and bubbles occurred in the films for high helium content in the films, and surface cracking and exfoliation were also observed.

  8. The effect of buffer layer on the thermochromic properties of undoped radio frequency sputtered VO{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Panagopoulou, M., E-mail: marpanag@mail.ntua.gr [School of Applied Mathematical and Physical Sciences, National Technical University of Athens, GR 157 80, Zografou Campus, Athens (Greece); Gagaoudakis, E. [Physics Department, University of Crete, 71003 Heraklion, Crete (Greece); Institute of Electronic Structure & Laser (IESL), Foundation for Research and Technology — FORTH-Hellas, P.O. Box 1385, Heraklion 70013, Crete (Greece); Aperathitis, E.; Michail, I. [Institute of Electronic Structure & Laser (IESL), Foundation for Research and Technology — FORTH-Hellas, P.O. Box 1385, Heraklion 70013, Crete (Greece); Kiriakidis, G. [Physics Department, University of Crete, 71003 Heraklion, Crete (Greece); Institute of Electronic Structure & Laser (IESL), Foundation for Research and Technology — FORTH-Hellas, P.O. Box 1385, Heraklion 70013, Crete (Greece); Tsoukalas, D.; Raptis, Y.S. [School of Applied Mathematical and Physical Sciences, National Technical University of Athens, GR 157 80, Zografou Campus, Athens (Greece)

    2015-11-02

    Thermochromic (TC) coatings can find use in a wide range of applications. Vanadium dioxide (VO{sub 2}) specifically, can be potentially used as a smart window coating, as it presents a metal-to-semiconductor transition close to the room temperature (T{sub c} = 68 °C). This results in low transmission in the infrared (thermal) part of the spectrum, while preserving its transmittance in the visible. In the present work, vanadium dioxide (VO{sub 2}) thin films with a thickness of ~ 85 nm were prepared by radio frequency sputtering, to investigate the influence of the buffer layer and deposition properties employed, on their thermochromic behavior. The substrates used were uncoated glass and pre-coated glasses with SnO{sub 2} or ZnON as buffer layer. The lowest growth temperature applied was 300 °C, yielding TC-VO{sub 2}, without the necessity of any post-growth treatment. The structure of the VO{sub 2} films was studied by X-ray diffraction and temperature-dependent micro Raman techniques, and the transition temperatures were determined through transmittance measurements. - Highlights: • RF-sputtered thermochromic VO{sub 2}, was grown at 300 °C and 400 °C. • Buffer layers of SnO{sub 2} or ZnON are used over glass. • Low Tc, without post-treatment, for both buffer-layers and T-growth • Thermochromicity of glass/VO{sub 2}, at low T-growth, is improved by ZnON buffer layer.

  9. Zn Thin Film Deposition for Fe Layer Shielding Use the Sputtering Technique on Cylindrical Form

    International Nuclear Information System (INIS)

    Yunanto; Tjipto Sujitno, BA; Suprapto; Simbolon, Sahat

    2002-01-01

    Deposition of thin film on Fe substrate use sputtering technique on cylindrical form was carried out. The purpose of this research is to protect Fe due to the corrosion with Zn thin film. Sputtering method was proposed to protect a component of complex form. Substrate has functioned as anode, meanwhile target in cylindrical form as a cathode. Argon ion from anode bombard Zn with enough energy for releasing Zn. Zn atom would scatter and some of then was focused on the anode. For testing Zn atom on Fe by using XRF and corrosion rate with potentiostat. It was found that corrosion rate was decreased from 0.051 mpy to 0.031 mpy on 0.63 % of Fe substrate. (author)

  10. Nucleation of ultrathin silver layer by magnetron sputtering in Ar/N2 plasma

    Czech Academy of Sciences Publication Activity Database

    Bulíř, Jiří; Novotný, Michal; Lančok, Ján; Fekete, Ladislav; Drahokoupil, Jan; Musil, Jindřich

    2013-01-01

    Roč. 228, č. 1 (2013), S86-S90 ISSN 0257-8972 R&D Projects: GA ČR(CZ) GAP108/11/1298; GA ČR GP202/09/P324 Institutional support: RVO:68378271 Keywords : ultrathin silver * magnetron sputtering * spectral ellipsometry * in-situ monitoring Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.199, year: 2013

  11. Studies of temperature and flux dependences of sputtering yield of nickel from two-layered films of Ni-Ni/sub 3/C

    Energy Technology Data Exchange (ETDEWEB)

    Morita, K.; Ohno, H.; Hayashibara, M.; Itoh, N. (Nagoya Univ. (Japan). Dept. of Crystalline Materials Science)

    1984-03-01

    Rutherford backscattering measurements of ion-induced sputtering of nickel films that are backed by nickel-carbide films on the non-irradiated side have been carried out at various temperature using 5 keV Ar/sup +/ ions of various fluxes. It is found that at elevated temperatures the yields of atomic fluxes sputtered from the composite specimen depend strongly on ion flux. The sputtering of nickel atoms is suppressed substantially by segregated carbon layers for ion fluxes below a certain critical value. As the ion flux is increased the sputtering yield of carbon is found to decrease monotonically, while that of nickel increase abruptly above the critical flux to a maximum value 4 times the elemental yield and then decreases asymptotically to 1/4 of the elemental yield.

  12. Epitaxial growth of BiFeO3 films on TiN under layers by sputtering deposition

    Directory of Open Access Journals (Sweden)

    Yue Wang

    2017-05-01

    Full Text Available BiFeO3/TiN/MgO (001 films have been prepared by magneton sputtering, where TiN serves as a conductive under layer. X-ray diffraction profiles and cross-sectional transmission electron microscopy images reveal that not only (001-epitaxial BiFeO3 films are obtained, but also both tetragonal and rhombohedral phases co-exist in BiFeO3 films. Their crystallographic relationship is shown as following: tetragonal-BiFeO3 (001 [100]//TiN (001 [100]//MgO (001 [100] and rhombohedral-BiFeO3 (001 [100]//TiN (001 [100]//MgO (001 [100]. Besides, an oxidized TiN layer (∼ 20 nm has also been detected between BiFeO3 and TiN layers and its formation may originate from oxygen inter-diffusion from BiFeO3 layer. Despite of the existence of the oxidized TiN layer, it does not affect the epitaxial growth of BiFeO3 films. On the other hand, the coercivity electric field obtained in ferroelectric loop of BiFeO3 is greatly enhanced to 49 MV/cm due to the existence of oxidized TiN layer.

  13. Influence of ferroelectric layer on artificial multiferroic LSMO/BTO bilayers deposited by Dc and RF sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez, J. E.; Gomez, M. E.; Lopera, W. [Universidad del Valle, Department of Physics, A. A. 25360 Cali (Colombia)

    2016-11-01

    La{sub 2/3}Sr{sub 1/3}MnO{sub 3} (LSMO)/BaTiO{sub 3} (BTO) bilayers were deposited on (001) SrTiO{sub 3} substrates via Dc and RF sputtering at pure oxygen atmosphere at a substrate temperature of 830 degrees Celsius. We studied the structural, electrical and magnetic properties on LSMO/BTO bilayers, when LSMO thickness is fixed at nm and BTO thickness is varied from 20 to 100 nm. Reciprocal Space Maps in LSMO show a strained growth for all samples, while BTO layers are always relaxed. Magnetization and electrical measurements indicate the influence of the ferroelectric layer, due to saturation magnetization increases from 500 to 590 emu/cm{sup 3} and coercive field decreases from 178 to 82 Oe with BTO thickness. Mean Field mechanism is identified on all samples with critical exponent β between 0.42 and 0.54. Resistivity measurements show electron-electron and magnon-magnon scattering conduction mechanisms. The influence on magnetic and electrical properties of bilayers with BTO thickness is attributed to crystallographic strains at the interface and the corresponding relaxation with increasing BTO layer thickness. The thickness of the individual layers were obtained by X-ray reflectivity measurements in the bilayers, not shown. X-ray diffraction and Reciprocal Space Maps measurements show highly textured layers with preferential growth in the c-axis direction. (Author)

  14. Deuterium trapping in the carbon-silicon co-deposition layers prepared by RF sputtering in D2 atmosphere

    Science.gov (United States)

    Zhang, Hongliang; Zhang, Weiyuan; Su, Ranran; Tu, Hanjun; Shi, Liqun; Hu, Jiansheng

    2018-04-01

    Deuterated carbon-silicon layers co-deposited on graphite and silicon substrates by radio frequency magnetron sputtering in pure D2 plasma were produced to study deuterium trapping and characteristics of the C-Si layers. The C-Si co-deposited layers were examined by ion beam analysis (IBA), Raman spectroscopy (RS), infrared absorption (IR) spectroscopy, thermal desorption spectroscopy (TDS) and scanning electron microscopy (SEM). It was found that the growth rate of the C-Si co-deposition layer decreased with increasing temperature from 350 K to 800 K, the D concentration and C/Si ratios increased differently on graphite and silicon substrates. TDS shows that D desorption is mainly as D2, HD, HDO, CD4, and C2D4 and release peaks occurred at temperatures of less than 900 K. RS and IR analysis reveal that the structure of the C-Si layers became more disordered with increasing temperatures. Rounded areas of peeling with 1-2 μm diameters were observed on the surface.

  15. The Photocatalytic Activity and Compact Layer Characteristics of TiO2 Films Prepared Using Radio Frequency Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    H. C. Chang

    2014-01-01

    Full Text Available TiO2 compact layers are used in dye-sensitized solar cells (DSSCs to prevent charge recombination between the electrolyte and the transparent conductive substrate (indium tin oxide, ITO; fluorine-doped tin oxide, FTO. Thin TiO2 compact layers are deposited onto ITO/glass by means of radio frequency (rf magnetron sputtering, using deposition parameters that ensure greater photocatalytic activity and increased DSSC conversion efficiency. The photoinduced decomposition of methylene blue (MB and the photoinduced hydrophilicity of the TiO2 thin films are also investigated. The photocatalytic performance characteristics for the deposition of TiO2 films are improved by using the Grey-Taguchi method. The average transmittance in the visible region exceeds 85% for all samples. The XRD patterns of the TiO2 films, for sol-gel with spin coating of porous TiO2/TiO2 compact/ITO/glass, show a good crystalline structure. In contrast, without the TiO2 compact layer (only porous TiO2, the peak intensity of the anatase (101 plane in the XRD patterns for the TiO2 film has a lower value, which demonstrates inferior crystalline quality. With a TiO2 compact layer to prevent charge recombination, a higher short-circuit current density is obtained. The DSSC with the FTO/glass and Pt counter electrode demonstrates the energy conversion efficiency increased.

  16. Copper based superconductors by the combination of blocking and mediating layers

    International Nuclear Information System (INIS)

    Shimizu, K.; Nobumasa, H.; Kawai, T.

    1992-01-01

    Copper based high temperature superconductors are composed of Cu-O 2 sheets in combination with thin atomic mediating layers and thick blocking layers which mediate and intercept interactions between Cu-O 2 sheets, respectively. New possible superconductors can be designed by the stacking of the Cu-O 2 sheets along with the periodic insertion of the mediating layers and different kinds of blocking layers. (orig.)

  17. Electron beam induced coloration and luminescence in layered structure of WO3 thin films grown by pulsed dc magnetron sputtering

    International Nuclear Information System (INIS)

    Karuppasamy, A.; Subrahmanyam, A.

    2007-01-01

    Tungsten oxide thin films have been deposited by pulsed dc magnetron sputtering of tungsten in argon and oxygen atmosphere. The as-deposited WO 3 film is amorphous, highly transparent, and shows a layered structure along the edges. In addition, the optical properties of the as-deposited film show a steplike behavior of extinction coefficient. However, the electron beam irradiation (3.0 keV) of the as-deposited films results in crystallization, coloration (deep blue), and luminescence (intense red emission). The above changes in physical properties are attributed to the extraction of oxygen atoms from the sample and the structural modifications induced by electron bombardment. The present method of coloration and luminescence has a potential for fabricating high-density optical data storage device

  18. Study of ion beam sputtered Fe/Si interfaces as a function of Si layer thickness

    Science.gov (United States)

    Kumar, Anil; Brajpuriya, Ranjeet; Singh, Priti

    2018-01-01

    The exchange interaction in metal/semiconductor interfaces is far from being completely understood. Therefore, in this paper, we have investigated the nature of silicon on the Fe interface in the ion beam deposited Fe/Si/Fe trilayers keeping the thickness of the Fe layers fixed at 3 nm and varying the thickness of the silicon sandwich layer from 1.5 nm to 4 nm. Grazing incidence x-ray diffraction and atomic force microscopy techniques were used, respectively, to study the structural and morphological changes in the deposited films as a function of layer thickness. The structural studies show silicide formation at the interfaces during deposition and better crystalline structure of Fe layers at a lower spacer layer thickness. The magnetization behavior was investigated using magneto-optical Kerr effect, which clearly shows that coupling between the ferromagnetic layers is highly influenced by the semiconductor spacer layer thickness. A strong antiferromagnetic coupling was observed for a value of tSi = 2.5 nm but above this value an unexpected behavior of hysteresis loop (step like) with two coercivity values is recorded. For spacer layer thickness greater than 2.5 nm, an elemental amorphous Si layer starts to appear in the spacer layer in addition to the silicide layer at the interfaces. It is observed that in the trilayer structure, Fe layers consist of various stacks, viz., Si doped Fe layers, ferromagnetic silicide layer, and nonmagnetic silicide layer at the interfaces. The two phase hysteresis loop is explained on the basis of magnetization reversal of two ferromagnetic layers, independent of each other, with different coercivities. X-ray photo electron spectroscopy technique was also used to study interfaces characteristics as a function of tSi.

  19. Physical and chemical degradation behavior of sputtered aluminum doped zinc oxide layers for Cu(In,Ga)Se2 solar cells

    NARCIS (Netherlands)

    Theelen, M.; Boumans, T.; Stegeman, F.; Colberts, F.; Illiberi, A.; Berkum, J. van; Barreau, N.; Vroon, Z.; Zeman, M.

    2014-01-01

    Sputtered aluminum doped zinc oxide (ZnO:Al) layers on borosilicate glass were exposed to damp heat (85 C/85% relative humidity) for 2876 h to accelerate the physical and chemical degradation behavior. The ZnO:Al samples were characterized by electrical, compositional and optical measurements before

  20. Carbon thin films deposited by the magnetron sputtering technique using cobalt, copper and nickel as buffer-layers; Filmes finos de carbono depositados por meio da tecnica de magnetron sputtering usando cobalto, cobre e niquel como buffer-layers

    Energy Technology Data Exchange (ETDEWEB)

    Costa e Silva, Danilo Lopes

    2015-11-01

    In this work, carbon thin films were produced by the magnetron sputtering technique using single crystal substrates of alumina c-plane (0001) and Si (111) and Si (100) substrates, employing Co, Ni and Cu as intermediate films (buffer-layers). The depositions were conducted in three stages, first with cobalt buffer-layers where only after the production of a large number of samples, the depositions using cooper buffer-layers were carried out on Si substrates. Then, depositions were performed with nickel buffer layers using single-crystal alumina substrates. The crystallinity of the carbon films was evaluated by using the technique of Raman spectroscopy and, then, by X-ray diffraction (XRD). The morphological characterization of the films was performed by scanning electron microscopy (SEM and FEG-SEM) and high-resolution transmission electron microscopy (HRTEM). The XRD peaks related to the carbon films were observed only in the results of the samples with cobalt and nickel buffer-layers. The Raman spectroscopy showed that the carbon films with the best degree of crystallinity were the ones produced with Si (111) substrates, for the Cu buffers, and sapphire substrates for the Ni and Co buffers, where the latter resulted in a sample with the best crystallinity of all the ones produced in this work. It was observed that the cobalt has low recovering over the alumina substrates when compared to the nickel. Sorption tests of Ce ions by the carbon films were conducted in two samples and it was observed that the sorption did not occur probably because of the low crystallinity of the carbon films in both samples. (author)

  1. Sputter-deposited polycrystalline tantalum-doped SnO{sub 2} layers

    Energy Technology Data Exchange (ETDEWEB)

    Weidner, Mirko, E-mail: mweidner@surface.tu-darmstadt.de; Brötz, Joachim; Klein, Andreas

    2014-03-31

    In this study, tin oxide (SnO{sub 2}) thin films doped with 1 cation percent tantalum were deposited on amorphous fused silica substrates by RF-magnetron sputter deposition. Electrical and optical properties were subsequently measured and analyzed as a function of deposition temperature (300 to 700 °C) and oxygen ratio in the process gas (0 to 50%). In situ photoelectron spectroscopy was used to determine tantalum incorporation, sample stoichiometry, valence band electronic structure and Fermi level position. Samples were analyzed with respect to their optical and electrical characteristics by spectral transmittance and Hall measurement. Electrical resistivity reached values as low as 1.7 × 10{sup −3} Ω cm with a charge carrier density of 3.3 × 10{sup 20} cm{sup −3} and a mobility of 12 cm{sup 2} V{sup −1} s{sup −1}. Electrical transport properties were related to structural properties as determined by atomic force microscopy, scanning electron microscopy and X-ray diffraction. It was found that electrical properties are a strong function of substrate temperature, mainly due to a reduced charge carrier density for deposition temperatures below 700 °C. This is thought to be caused by an intrinsic compensation mechanism which has not yet been identified. - Highlights: • SnO{sub 2}:Ta films were deposited at varying temperatures and oxygen partial pressures. • In situ X-ray and ultraviolet photoelectron spectra of sputtered SnO{sub 2}:Ta are presented. • Electrical properties decrease rapidly for substrate temperatures lower than 700 °C. • Authors suggest deposition temperature dependent compensation mechanism. • Nature of compensation mechanism unclear, possibly point defect.

  2. A PCBM-Modified TiO2 Blocking Layer towards Efficient Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Gang Lu

    2017-01-01

    Full Text Available Organometal halide perovskite as a promising absorber in solar cells has caught tremendous attention in the past few years. Herein, a hydrophobic PCBM layer was introduced into planar heterojunction perovskite solar cells to form the TiO2/PCBM double blocking layer. The bilayer structure assures the formation of a dense, smooth, and pinhole-free blocking layer. And the PCBM layer can also be in favor of larger grain size perovskite film and further passivate the TiO2 blocking layer. Scanning electron microscope, atomic force microscope, and X-ray diffraction (XRD results suggest the formation of a uniform and compact CH3NH3PbI3−xClx perovskite layer on the PCBM-modified TiO2 blocking layer. The solar cell has reached a PCE up to 16.37%, which is greatly larger than the control device with a PCE of 10.81%.

  3. Structural and electrical properties of AlN layers grown on silicon by reactive RF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Bazlov, N., E-mail: n.bazlov@spbu.ru; Pilipenko, N., E-mail: nelly.pilipenko@gmail.com; Vyvenko, O.; Petrov, Yu.; Mikhailovskii, V.; Ubyivovk, E. [St. Petersburg State University, Ulyanovskaya 1, Petrodvorets, St.Petersburg (Russian Federation); Kotina, I. [St. Petersburg Nuclear Physics Institute, Gatchina, Leningradskii oblast, 188300 (Russian Federation); Zharinov, V. [INPAC—Institute for Nanoscale Physics and Chemistry, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium)

    2016-06-17

    AlN films of different thicknesses were deposited on n-Si (100) substrates by reactive radio frequency (rf) magnetron sputtering. Dependences of structure and electrical properties on thickness of deposited films were researched. The structures of the films were analyzed with scanning electron microscopy (SEM) and with transmitting electron microscopy (TEM). Electrical properties of the films were investigated on Au-AlN-(n-Si) structures by means of current-voltage (I-V), capacitance-voltage (C-V) and deep level transient spectroscopy (DLTS) techniques. Electron microscopy investigations had shown that structure and chemical composition of the films were thickness stratified. Near silicon surface layer was amorphous aluminum oxide one contained traps of positive charges with concentration of about 4 × 10{sup 18} cm{sup −3}. Upper layers were nanocrystalline ones consisted of both wurzite AlN and cubic AlON nanocrystals. They contained traps both positive and negative charges which were situated within 30 nm distance from silicon surface. Surface densities of these traps were about 10{sup 12} cm{sup −2}. Electron traps with activation energies of (0.2 ÷ 0.4) eV and densities of about 10{sup 10} cm{sup −2} were revealed on interface between aluminum oxide layer and silicon substrate. Their densities varied weakly with the film thickness.

  4. Application of Analytical Model of the Electric Potential Distribution for Calculation of Charged Particle Dynamics in a Near-Wall Layer and Sputtering of the Plasma Facing Surfaces

    Czech Academy of Sciences Publication Activity Database

    Borodkina, I.E.; Komm, Michael; Tsvetkov, I.V.

    2015-01-01

    Roč. 58, č. 4 (2015), s. 438-445 ISSN 1064-8887 Institutional support: RVO:61389021 Keywords : plasma-surface interaction * magnetic pre-layer * Debye layer * inclined magnetic field * sputtering Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.667, year: 2015 http://link.springer.com/article/10.1007%2Fs11182-015-0518-5

  5. Carbon thin films deposited by the magnetron sputtering technique using cobalt, copper and nickel as buffer-layers

    International Nuclear Information System (INIS)

    Costa e Silva, Danilo Lopes

    2015-01-01

    In this work, carbon thin films were produced by the magnetron sputtering technique using single crystal substrates of alumina c-plane (0001) and Si (111) and Si (100) substrates, employing Co, Ni and Cu as intermediate films (buffer-layers). The depositions were conducted in three stages, first with cobalt buffer-layers where only after the production of a large number of samples, the depositions using cooper buffer-layers were carried out on Si substrates. Then, depositions were performed with nickel buffer layers using single-crystal alumina substrates. The crystallinity of the carbon films was evaluated by using the technique of Raman spectroscopy and, then, by X-ray diffraction (XRD). The morphological characterization of the films was performed by scanning electron microscopy (SEM and FEG-SEM) and high-resolution transmission electron microscopy (HRTEM). The XRD peaks related to the carbon films were observed only in the results of the samples with cobalt and nickel buffer-layers. The Raman spectroscopy showed that the carbon films with the best degree of crystallinity were the ones produced with Si (111) substrates, for the Cu buffers, and sapphire substrates for the Ni and Co buffers, where the latter resulted in a sample with the best crystallinity of all the ones produced in this work. It was observed that the cobalt has low recovering over the alumina substrates when compared to the nickel. Sorption tests of Ce ions by the carbon films were conducted in two samples and it was observed that the sorption did not occur probably because of the low crystallinity of the carbon films in both samples. (author)

  6. Effects of GaN/AlGaN/Sputtered AlN nucleation layers on performance of GaN-based ultraviolet light-emitting diodes

    Science.gov (United States)

    Hu, Hongpo; Zhou, Shengjun; Liu, Xingtong; Gao, Yilin; Gui, Chengqun; Liu, Sheng

    2017-03-01

    We report on the demonstration of GaN-based ultraviolet light-emitting diodes (UV LEDs) emitting at 375 nm grown on patterned sapphire substrate (PSS) with in-situ low temperature GaN/AlGaN nucleation layers (NLs) and ex-situ sputtered AlN NL. The threading dislocation (TD) densities in GaN-based UV LEDs with GaN/AlGaN/sputtered AlN NLs were determined by high-resolution X-ray diffraction (XRD) and cross-sectional transmission electron microscopy (TEM), which revealed that the TD density in UV LED with AlGaN NL was the highest, whereas that in UV LED with sputtered AlN NL was the lowest. The light output power (LOP) of UV LED with AlGaN NL was 18.2% higher than that of UV LED with GaN NL owing to a decrease in the absorption of 375 nm UV light in the AlGaN NL with a larger bandgap. Using a sputtered AlN NL instead of the AlGaN NL, the LOP of UV LED was further enhanced by 11.3%, which is attributed to reduced TD density in InGaN/AlInGaN active region. In the sputtered AlN thickness range of 10-25 nm, the LOP of UV LED with 15-nm-thick sputtered AlN NL was the highest, revealing that optimum thickness of the sputtered AlN NL is around 15 nm.

  7. Sputtered tungsten-based ternary and quaternary layers for nanocrystalline diamond deposition.

    Science.gov (United States)

    Walock, Michael J; Rahil, Issam; Zou, Yujiao; Imhoff, Luc; Catledge, Shane A; Nouveau, Corinne; Stanishevsky, Andrei V

    2012-06-01

    Many of today's demanding applications require thin-film coatings with high hardness, toughness, and thermal stability. In many cases, coating thickness in the range 2-20 microm and low surface roughness are required. Diamond films meet many of the stated requirements, but their crystalline nature leads to a high surface roughness. Nanocrystalline diamond offers a smoother surface, but significant surface modification of the substrate is necessary for successful nanocrystalline diamond deposition and adhesion. A hybrid hard and tough material may be required for either the desired applications, or as a basis for nanocrystalline diamond film growth. One possibility is a composite system based on carbides or nitrides. Many binary carbides and nitrides offer one or more mentioned properties. By combining these binary compounds in a ternary or quaternary nanocrystalline system, we can tailor the material for a desired combination of properties. Here, we describe the results on the structural and mechanical properties of the coating systems composed of tungsten-chromium-carbide and/or nitride. These WC-Cr-(N) coatings are deposited using magnetron sputtering. The growth of adherent nanocrystalline diamond films by microwave plasma chemical vapor deposition has been demonstrated on these coatings. The WC-Cr-(N) and WC-Cr-(N)-NCD coatings are characterized with atomic force microscopy and SEM, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and nanoindentation.

  8. Effect of passivation layer grown by atomic layer deposition and sputtering processes on Si quantum dot superlattice to generate high photocurrent for high-efficiency solar cells

    Science.gov (United States)

    Maksudur Rahman, Mohammad; Higo, Akio; Sekhar, Halubai; Erman Syazwan, Mohd; Hoshi, Yusuke; Usami, Noritaka; Samukawa, Seiji

    2016-03-01

    The effect of passivation films on a Si quantum dot superlattice (QDSL) was investigated to generate high photocurrent in solar-cell applications. Three types of passivation films, sputter-grown amorphous silicon carbide (a-SiC), hydrogenated a-SiC (a-SiC:H), and atomic-layer-deposited aluminum oxide (ALD-Al2O3), were used to passivate the Si QDSLs containing a stack of four 4 nm Si nanodisks (NDs) and 2 nm silicon carbide (SiC) films fabricated by neutral beam etching (NBE). Because of the high surface-to-volume ratio typically present in quantum Si-NDs formed in the top-down NBE process, there is a tendency to form larger surface dangling bonds on untreated Si-ND surfaces as well as to have short distance (RMS) of 1.09 nm with respect to sputter-grown a-SiC (RMS: 1.75 nm) and a-SiC:H (RMS: 1.54 nm) films. Conductive atomic force microscopy (CAFM) revealed that ALD-Al2O3 passivation decreased the surface-leakage current as a result of proper passivation of side-wall surface defects in the QDSLs. The carrier transport characteristics were extracted from the QDSLs using the photovoltaic (PV) properties of p++/i/n+ solar cells, where the QDSLs consisted of different passivation layers acting as intermediate layers (i-layers) between the high-doping-density p++ Si (1 × 1020 cm-3) and n+ Si (1 × 1019 cm-3) substrates. High-doping-density p++ Si acted as a hole conductor instead of a photocarrier generator, hence, we could observe the PV properties of the i-layers. The highest short-circuit current density of 4.75 mA cm-2 was generated from the QDSL with the ALD-Al2O3-passivated surface, which is suitable for high-efficiency QD solar cells compared with a-SiC-passivated (0.04 mA cm-2) and a-SiC:H-passivated (0.37 mA cm-2) QDSL surfaces.

  9. Combinatorial Reactive Sputtering of In2S3 as an Alternative Contact Layer for Thin Film Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Siol, Sebastian; Dhakal, Tara P.; Gudavalli, Ganesh S.; Rajbhandari, Pravakar P.; DeHart, Clay; Baranowski, Lauryn L.; Zakutayev, Andriy

    2016-06-08

    High-throughput computational and experimental techniques have been used in the past to accelerate the discovery of new promising solar cell materials. An important part of the development of novel thin film solar cell technologies, that is still considered a bottleneck for both theory and experiment, is the search for alternative interfacial contact (buffer) layers. The research and development of contact materials is difficult due to the inherent complexity that arises from its interactions at the interface with the absorber. A promising alternative to the commonly used CdS buffer layer in thin film solar cells that contain absorbers with lower electron affinity can be found in ..beta..-In2S3. However, the synthesis conditions for the sputter deposition of this material are not well-established. Here, In2S3 is investigated as a solar cell contact material utilizing a high-throughput combinatorial screening of the temperature-flux parameter space, followed by a number of spatially resolved characterization techniques. It is demonstrated that, by tuning the sulfur partial pressure, phase pure ..beta..-In2S3 could be deposited using a broad range of substrate temperatures between 500 degrees C and ambient temperature. Combinatorial photovoltaic device libraries with Al/ZnO/In2S3/Cu2ZnSnS4/Mo/SiO2 structure were built at optimal processing conditions to investigate the feasibility of the sputtered In2S3 buffer layers and of an accelerated optimization of the device structure. The performance of the resulting In2S3/Cu2ZnSnS4 photovoltaic devices is on par with CdS/Cu2ZnSnS4 reference solar cells with similar values for short circuit currents and open circuit voltages, despite the overall quite low efficiency of the devices (-2%). Overall, these results demonstrate how a high-throughput experimental approach can be used to accelerate the development of contact materials and facilitate the optimization of thin film solar cell devices.

  10. Combinatorial Reactive Sputtering of In2S3 as an Alternative Contact Layer for Thin Film Solar Cells.

    Science.gov (United States)

    Siol, Sebastian; Dhakal, Tara P; Gudavalli, Ganesh S; Rajbhandari, Pravakar P; DeHart, Clay; Baranowski, Lauryn L; Zakutayev, Andriy

    2016-06-08

    High-throughput computational and experimental techniques have been used in the past to accelerate the discovery of new promising solar cell materials. An important part of the development of novel thin film solar cell technologies, that is still considered a bottleneck for both theory and experiment, is the search for alternative interfacial contact (buffer) layers. The research and development of contact materials is difficult due to the inherent complexity that arises from its interactions at the interface with the absorber. A promising alternative to the commonly used CdS buffer layer in thin film solar cells that contain absorbers with lower electron affinity can be found in β-In2S3. However, the synthesis conditions for the sputter deposition of this material are not well-established. Here, In2S3 is investigated as a solar cell contact material utilizing a high-throughput combinatorial screening of the temperature-flux parameter space, followed by a number of spatially resolved characterization techniques. It is demonstrated that, by tuning the sulfur partial pressure, phase pure β-In2S3 could be deposited using a broad range of substrate temperatures between 500 °C and ambient temperature. Combinatorial photovoltaic device libraries with Al/ZnO/In2S3/Cu2ZnSnS4/Mo/SiO2 structure were built at optimal processing conditions to investigate the feasibility of the sputtered In2S3 buffer layers and of an accelerated optimization of the device structure. The performance of the resulting In2S3/Cu2ZnSnS4 photovoltaic devices is on par with CdS/Cu2ZnSnS4 reference solar cells with similar values for short circuit currents and open circuit voltages, despite the overall quite low efficiency of the devices (∼2%). Overall, these results demonstrate how a high-throughput experimental approach can be used to accelerate the development of contact materials and facilitate the optimization of thin film solar cell devices.

  11. Evaluation of the electrical conductivity and corrosion resistance for layers deposited via sputtering on stainless steel

    Science.gov (United States)

    Blanco, J.; Salas, Y.; Jiménez, C.; Pineda, Y.; Bustamante, A.

    2017-12-01

    In some Engineering fields, we need that conductive materials have a mechanic performance and specific electrical for that they maintain conditions or corrosive attack if they are in the environment or if they are closed structure. The stainless steels have an inert film on their surface and it has the function to act in contrast to external agents who generates the corrosion, especially for stings, spoiling the film until to fail. We found a solution taking into account the electrical performance and the anticorrosive; into the process we put recovering of specific oxides on, stainless steel using the method of sputtering with Unbalanced Magnetron, (UBM) varying the oxygen in the reactive environment. The coating obtained had a thickness one micron approximately and we saw on serious structural uniformity [1]. The corrosion resistance was evaluated through the potentiodynamics polarization and electrochemical spectroscopy impedance in NACL according to the standard. The cathode protection is the most important method employed for the corrosion prevention of metallic structures in the soil or immersed on the water. The electrical resistivity was evaluated with the four points methods and it showed a behaviour of diode type in some substrates with a threshold potential in several volts. We noticed a simple resistance solution when it was analysed in the Nyquist graphics whit the Electrochemical Impedance Spectroscopy technique. With on equivalent circuit, for this reason we determinate a variation in the corrosion speed in almost two orders of magnitude when we analysed the potentiodynamics curve by Tafel approximation. The data obtained and analysed show that this type of surface modification maintains the conductivity condition at the interface, improving the resistance in relation whit the corrosion of these elements where the recovering allowed the ionic flow wished for overcoming threshold voltage, acting as an insulator in different cases.

  12. Prominent electric properties of BiFeO₃ shells sputtered on ZnO-nanorod cores with LaNiO₃ buffer layers.

    Science.gov (United States)

    Chiu, Kuan-Chang; Yang, Tung-Han; Wu, Jenn-Ming

    2013-06-07

    In this work, template-assisted methods were adopted to grow BiFeO3 (BFO)-nanorod arrays on substrates. Well-aligned ZnO-nanorod arrays (ZNAs) grown hydrothermally were chosen as positive templates. It was found that perovskite BFO could not be radio frequency (RF)-magnetron sputtered directly on a ZNA at elevated temperatures. Only amorphous BFO was obtained. However, polycrystalline BFO shells could be fabricated by RF-magnetron sputtering on ZNA templates by the introduction of LaNiO3 (LNO) buffer layers. The LNO buffer layer deposited on the ZNA by RF-magnetron sputtering was demonstrated to improve the adhesion and crystallization of the sequentially sputtered BFO shells. The electrical properties were evaluated by conductive atomic force microscopy and piezoresponse force microscopy. Bulk-limited Poole-Frenkel emission dominates the conduction of BFO shells at positive bias, while barrier-limited Schottky emission accounts for the conduction at negative bias due to the interface between the Pt/Ir-coated tip and the BFO. The piezoelectric coefficient (d33) was estimated to be ∼32.93 pm V(-1) and a polarization of 133 μC cm(-2) was derived. These values are higher than those reported previously for BFO films.

  13. Prominent electric properties of BiFeO3 shells sputtered on ZnO-nanorod cores with LaNiO3 buffer layers

    Science.gov (United States)

    Chiu, Kuan-Chang; Yang, Tung-Han; Wu, Jenn-Ming

    2013-06-01

    In this work, template-assisted methods were adopted to grow BiFeO3 (BFO)-nanorod arrays on substrates. Well-aligned ZnO-nanorod arrays (ZNAs) grown hydrothermally were chosen as positive templates. It was found that perovskite BFO could not be radio frequency (RF)-magnetron sputtered directly on a ZNA at elevated temperatures. Only amorphous BFO was obtained. However, polycrystalline BFO shells could be fabricated by RF-magnetron sputtering on ZNA templates by the introduction of LaNiO3 (LNO) buffer layers. The LNO buffer layer deposited on the ZNA by RF-magnetron sputtering was demonstrated to improve the adhesion and crystallization of the sequentially sputtered BFO shells. The electrical properties were evaluated by conductive atomic force microscopy and piezoresponse force microscopy. Bulk-limited Poole-Frenkel emission dominates the conduction of BFO shells at positive bias, while barrier-limited Schottky emission accounts for the conduction at negative bias due to the interface between the Pt/Ir-coated tip and the BFO. The piezoelectric coefficient (d33) was estimated to be ˜32.93 pm V-1 and a polarization of 133 μC cm-2 was derived. These values are higher than those reported previously for BFO films.

  14. Research Update: Reactively sputtered nanometer-thin ZrN film as a diffusion barrier between Al and boron layers for radiation detector applications

    Directory of Open Access Journals (Sweden)

    Negin Golshani

    2014-10-01

    Full Text Available In this paper, optimization of the process flow for PureB detectors is investigated. Diffusion barrier layers between a boron layer and the aluminum interconnect can be used to enhance the performance and visual appearance of radiation detectors. Few nanometers-thin Zirconium Nitride (ZrN layer deposited by reactive sputtering in a mixture of Ar/N2, is identified as a reliable diffusion barrier with better fabrication process compatibility than others. The barrier properties of this layer have been tested for different boron layers deposited at low and high temperatures with extensive optical microscopy analyses, electron beam induced current, SEM, and electrical measurements. This study demonstrated that spiking behavior of pure Al on Si can be prevented by the thin ZrN layer thus improving the performance of the radiation detectors fabricated using boron layer.

  15. Electrochemical Characterization of TiO 2 Blocking Layers for Dye-Sensitized Solar Cells

    KAUST Repository

    Kavan, Ladislav

    2014-07-31

    Thin compact layers of TiO2 are grown by thermal oxidation of Ti, by spray pyrolysis, by electrochemical deposition, and by atomic layer deposition. These layers are used in dye-sensitized solar cells to prevent recombination of electrons from the substrate (FTO or Ti) with the hole-conducting medium at this interface. The quality of blocking is evaluated electrochemically by methylviologen, ferro/ferricyanide, and spiro-OMeTAD as the model redox probes. Two types of pinholes in the blocking layers are classified, and their effective area is quantified. Frequency-independent Mott-Schottky plots are fitted from electrochemical impedance spectroscopy. Certain films of the thicknesses of several nanometers allow distinguishing the depletion layer formation both in the TiO2 film and in the FTO substrate underneath the titania film. The excellent blocking function of thermally oxidized Ti, electrodeposited film (60 nm), and atomic-layer-deposited films (>6 nm) is documented by the relative pinhole area of less than 1%. However, the blocking behavior of electrodeposited and atomic-layer-deposited films is strongly reduced upon calcination at 500 °C. The blocking function of spray-pyrolyzed films is less good but also less sensitive to calcination. The thermally oxidized Ti is well blocking and insensitive to calcination. © 2014 American Chemical Society.

  16. Sputter Deposited TiOx Thin-Films as Electron Transport Layers in Organic Solar Cells

    DEFF Research Database (Denmark)

    Mirsafaei, Mina; Bomholt Jensen, Pia; Lakhotiya, Harish

    solar cells that eliminates the need for light soaking and still allows for integration on flexible plastic substrates, which is beneficial for roll-to-roll mass production of flexible organic solar cells. 1. Steim, R.; Kogler, F. R.; Brabec, C. J., Interface materials for organic solar cells. Journal......The use of interfacial layers in organic solar cells has been investigated intensively over the past years, as it has a strong impact on both the power conversion efficiency and stability of the devices. Among the systems investigated are for example alkali salts, ionic liquids, neutral polymers...... transparency and favorable energy-level alignment with many commonly used electron-acceptor materials. There are several methods available for fabricating compact TiOx thin-films for use in organic solar cells, including sol-gel solution processing, spray pyrolysis and atomic-layer deposition; however...

  17. Spectroscopic ellipsometry on Si/SiO2/graphene tri-layer system exposed to downstream hydrogen plasma: Effects of hydrogenation and chemical sputtering

    International Nuclear Information System (INIS)

    Eren, Baran; Fu, Wangyang; Marot, Laurent; Calame, Michel; Steiner, Roland; Meyer, Ernst

    2015-01-01

    In this work, the optical response of graphene to hydrogen plasma treatment is investigated with spectroscopic ellipsometry measurements. Although the electronic transport properties and Raman spectrum of graphene change after plasma hydrogenation, ellipsometric parameters of the Si/SiO2/graphene tri-layer system do not change. This is attributed to plasma hydrogenated graphene still being electrically conductive, since the light absorption of conducting 2D materials does not depend on the electronic band structure. A change in the light transmission can only be observed when higher energy hydrogen ions (30 eV) are employed, which chemically sputter the graphene layer. An optical contrast is still apparent after sputtering due to the remaining traces of graphene and hydrocarbons on the surface. In brief, plasma treatment does not change the light transmission of graphene; and when it does, this is actually due to plasma damage rather than plasma hydrogenation

  18. A way to integrate multiple block layers for middle of line contact patterning

    Science.gov (United States)

    Kunnen, E.; Demuynck, S.; Brouri, M.; Boemmels, J.; Versluijs, J.; Ryckaert, J.

    2015-03-01

    It is clear today that further scaling towards smaller dimensions and pitches requires a multitude of additional process steps. Within this work we look for solutions to achieve a middle of line 193i based patterning scheme for N7 logic at a contacted poly pitch of 40-45 nm. At these pitches, trenches can still be printed by means of double patterning. However, they need to be blocked at certain positions because of a limited line end control below 90 nm pitch single print. Based on the 193i patterning abilities, the proposed SRAM (Static Random Access Memory) cell requires 5 blocking layers. Integrating 5 blocking layers is a new challenge since down to N10 one blocking layer was usually sufficient. The difficulty with multiple blocking layers is the removal of the masked parts, especially in cases of overlap. As a solution a novel patterning approach is proposed and tried out on relaxed dimensions (patent pending). The proposed solution is expected not to be sensitive to the number of blocking layers used, and tolerates their overlap. The stack is constructed to be compatible with N7 substrates such as SiGe or P:Si. Experimental results of the stack blocking performance on relaxed pitch will be presented and discussed.

  19. Fundamentals of surfactant sputtering

    International Nuclear Information System (INIS)

    Hofsaess, Hans; Zhang Kun

    2009-01-01

    We introduce a new sputter technique, utilizing the steady-state coverage of a substrate surface with up to 10 16 cm -2 of foreign atoms simultaneously during sputter erosion by combined ion irradiation and atom deposition. These atoms strongly modify the substrate sputter yield on atomic to macroscopic length scales and therefore act as surfactant atoms (a blend of 'surface active agent'). Depending on the surfactant-substrate combination, the novel technique allows enhanced surface smoothing, generation of novel surface patterns, shaping of surfaces and formation of ultra-thin films. Sputter yield attenuation is demonstrated for sputtering of Si and Fe substrates and different surfactant species using 5 keV Xe ions at different incidence angles and fluences up to 10 17 cm -2 . Analytical approaches and Monte Carlo simulations are used to predict the sputtering yield attenuation as function of surfactant coverage. For sputtering of Si with Au surfactants we observe high sputter yields despite a steady-state surfactant coverage, which can be explained by strong ion-induced interdiffusion of substrate and surfactant atoms and the formation of a buried Au x Si surfactant layer in dynamic equilibrium.

  20. Fouling layer characterization and pore-blocking mechanisms in an ...

    African Journals Online (AJOL)

    A pilot-scale UASB reactor coupled with an external ultrafiltration (UF) membrane was operated under three different hydraulic retention times (HRT: 4, 8 and 12 h) for municipal wastewater treatment in order to assess the composition and distribution of the fouling layer, as well as to identify the predominant fouling ...

  1. Optimization of Aircraft Seat Cushion Fire Blocking Layers.

    Science.gov (United States)

    1983-03-01

    function of cost and weight, and the costs of labor involved in assembling a ccmposite seat cushion. The same classes of high char yield polymers that are...SEAT LATER DESIGN REPORT NRBBNBsg$$$$$$NN$$R$$$$$ SEAT DESIGN NUMBER: 009 LAYER NAME CODE NO. S MANUFACTURER 5 COST FACTORS . LABOR ...72621, 9096.. 7SS43. 73757. 77147. DELTA COSTS 0. 8340. 2922. 1136. 4327. ACOSOS in Iho..aS Of dollars. COST SUIRNY REPORT Re ....... VONR3 MORFA

  2. Modelling of process formation of the nanocomposite TiN-Cu layers received by vacuum-arc evaporation of Ti and magnetron sputtering of Cu

    Science.gov (United States)

    B-D Tsyrenov, D.; Semenov, A. P.; Smirnyagina, N. N.

    2017-05-01

    Modeling a TiN-Cu layers deposition process on a fused silica substrate under given conditions is carried out in this work. Calculation formulas which allow to determine the films thickness and their uniformity, with a substrate holder being located at an angle of 45 degrees to the normals of mutually perpendicular planes of the evaporated titanium cathode and the magnetron sputtering copper cathode, are given. The results of this work will be used to analyze the distribution velocity of the substance condensation flow and the character of the formed composite layers depending on the geometry of the cathode-substrate system.

  3. Improvement of Short-Circuit Current Density in Dye-Sensitized Solar Cells Using Sputtered Nanocolumnar TiO2 Compact Layer

    Directory of Open Access Journals (Sweden)

    Lung-Chien Chen

    2010-01-01

    Full Text Available The effect of a nanocolumnar TiO2 compact layer in dye-sensitized solar cells (DSSCs was examined. Such a compact layer was sputtered on a glass substrate with an indium tin oxide (ITO film using TiO2 powder as the raw material, with a thickness of ~100 nm. The compact layer improved the short-circuit current density and the efficiency of conversion of solar energy to electricity by the DSSC by 53.37% and 59.34%, yielding values of 27.33 mA/cm2 and 9.21%, respectively. The performance was attributed to the effective electron pathways in the TiO2 compact layer, which reduced the back reaction by preventing direct contact between the redox electrolyte and the conductive substrate.

  4. Morphology and photoluminescence of ZnO nanorods grown on sputtered GaN films with intermediate ZnO seed layer

    Energy Technology Data Exchange (ETDEWEB)

    Nandi, R. [Department of Physics, Indian Institute of Technology Bombay, Mumbai, 400076 (India); Srinivasa, R.S. [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, 400076 (India); Major, S.S., E-mail: syed@iitb.ac.in [Department of Physics, Indian Institute of Technology Bombay, Mumbai, 400076 (India)

    2016-10-01

    ZnO nanorods (NRs) were grown by chemical bath deposition on sputtered GaN over Si with and without sputtered ZnO seed layers. The effect of ZnO seed layer thickness, precursor concentration and growth temperature on the morphology and photoluminescence (PL) of ZnO-NRs has been studied. Scanning electron microscopy studies at different stages of growth have shown that the thickness of ZnO seed layer is critically important for controlling the growth behavior, morphology and density of ZnO-NRs on GaN surface. ZnO-NRs on bare GaN/Si grow with a large diameter and small aspect ratio of ∼4, displaying the tendency of lateral growth. Introduction of a thin ZnO seed layer (10 nm) under optimized precursor concentration and temperature drastically increases the aspect ratio to ∼16, due to partial coverage of ZnO on GaN surface and a moderate density of nucleation with small critical size. ZnO seed layers of higher thickness (50 nm and 100 nm) result in reduced aspect ratio due to increase in nucleation density and limited availability of reacting species. Increase in precursor concentration results in pronounced lateral growth and the decrease in growth temperature also results in compact nanorods with reduced aspect ratios. Room temperature photoluminescence (PL) studies show that ZnO-NRs on GaN, grown with or without ZnO seed layer under optimized precursor concentration and temperature, display high near-band-edge luminescence and negligible defect emission, compared to the nanorods on a ZnO seed layer over Si, as well as those grown at higher precursor concentration and lower temperatures. The enhanced PL is attributed to the absence of crystalline defects at nanorod interfaces due to lateral coalescence, arising from the moderate density and slight misalignment of the nanorods. - Highlights: • ZnO nanorods grown on sputtered GaN film display strong tendency of lateral growth. • Nanorods grown on 10 nm ZnO/GaN display moderate density and high aspect ratios.

  5. The Influences of Thickness on the Optical and Electrical Properties of Dual-Ion-Beam Sputtering-Deposited Molybdenum-Doped Zinc Oxide Layer

    Directory of Open Access Journals (Sweden)

    Chin-Chiuan Kuo

    2011-01-01

    Full Text Available The thickness of transparent conductive oxide (TCO layer significantly affects not only the optical and electrical properties, but also its mechanical durability. To evaluate these influences on the molybdenum-doped zinc oxide layer deposited on a flexible polyethersulfone (PES substrate by using a dual-ion-beam sputtering system, films with various thicknesses were prepared at a same condition and their optical and electrical performances have been compared. The results show that all the deposited films present a crystalline wurtzite structure, but the preferred orientation changes from (002 to (100 with increasing the film thickness. Thicker layer contains a relative higher carrier concentration, but the consequently accumulated higher internal stress might crack the film and retard the carrier mobility. The competition of these two opposite trends for carrier concentration and carrier mobility results in that the electrical resistivity of molybdenum-doped zinc oxide first decreases with the thickness but suddenly rises when a critical thickness is reached.

  6. Enhanced JPEG2000 Quality Scalability through Block-Wise Layer Truncation

    Directory of Open Access Journals (Sweden)

    Auli-Llinas Francesc

    2010-01-01

    Full Text Available Quality scalability is an important feature of image and video coding systems. In JPEG2000, quality scalability is achieved through the use of quality layers that are formed in the encoder through rate-distortion optimization techniques. Quality layers provide optimal rate-distortion representations of the image when the codestream is transmitted and/or decoded at layer boundaries. Nonetheless, applications such as interactive image transmission, video streaming, or transcoding demand layer fragmentation. The common approach to truncate layers is to keep the initial prefix of the to-be-truncated layer, which may greatly penalize the quality of decoded images, especially when the layer allocation is inadequate. So far, only one method has been proposed in the literature providing enhanced quality scalability for compressed JPEG2000 imagery. However, that method provides quality scalability at the expense of high computational costs, which prevents its application to the aforementioned applications. This paper introduces a Block-Wise Layer Truncation (BWLT that, requiring negligible computational costs, enhances the quality scalability of compressed JPEG2000 images. The main insight behind BWLT is to dismantle and reassemble the to-be-fragmented layer by selecting the most relevant codestream segments of codeblocks within that layer. The selection process is conceived from a rate-distortion model that finely estimates rate-distortion contributions of codeblocks. Experimental results suggest that BWLT achieves near-optimal performance even when the codestream contains a single quality layer.

  7. Two-layer-atmospheric blocking in a medium with high nonlinearity and lateral dispersion

    Science.gov (United States)

    Osman, M. S.; Abdel-Gawad, H. I.; El Mahdy, M. A.

    2018-03-01

    Herein, the extended coupled Kadomtsev-Petviashvili equation (CKPE) with lateral dispersion is investigated for studying the atmospheric blocking in two layers. A variety of new types of polynomial solutions for the CKPE is obtained using the unified method. Furthermore, we use the Hamiltonian systems with two degrees of freedom to discuss the stability of the obtained solutions through the bifurcation diagrams.

  8. Ion blocking and channeling studies of heteroepitaxial GaN layers

    International Nuclear Information System (INIS)

    Flagmeyer, R.; Ehrlich, C.; Geist, V.; Otto, G.

    1978-01-01

    Ion channeling and blocking in backscattering measurements were used for the characterization of thin epitaxial GaN layers, which have varied lattice imperfections involved by different growth conditions. In particular, the following characteristics were examined: (1) the thickness and the uniformity of the layers, (2) the depth dependence of the crystalline imperfection, (3) the dislocation density, (4) the spread in the orientation distribution of tilted crystallites, and (5) some other types of imperfections, such as stacking faults, double positioning, twins and bending of the layer

  9. Efficiency of solution-processed multilayer polymer light-emitting diodes using charge blocking layers

    Science.gov (United States)

    Kasparek, Christian; Rörich, Irina; Blom, Paul W. M.; Wetzelaer, Gert-Jan A. H.

    2018-01-01

    By blending semiconducting polymers with the cross-linkable matrix ethoxylated-(4)-bisphenol-a-dimethacrylate (SR540), an insoluble layer is acquired after UV-illumination. Following this approach, a trilayer polymer light-emitting diode (PLED) consisting of a blend of poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine] (poly-TPD) and SR540 as an electron-blocking layer, Super Yellow-Poly(p-phenylene vinylene) (SY-PPV) blended with SR540 as an emissive layer, and poly(9,9-di-n-octylfluorenyl-2,7-diyl) as a hole-blocking layer is fabricated from solution. The trilayer PLED shows a 23% increase in efficiency at low voltage as compared to a single layer SY-PPV PLED. However, at higher voltage, the advantage in current efficiency gradually decreases. A combined experimental and modelling study shows that the increased efficiency is not only due to the elimination of exciton quenching at the electrodes but also due to suppressed nonradiative trap-assisted recombination due to carrier confinement. At high voltages, holes can overcome the hole-blocking barrier, which explains the efficiency roll-off.

  10. Improved charge trapping flash device with Al2O3/HfSiO stack as blocking layer

    International Nuclear Information System (INIS)

    Zheng Zhi-Wei; Huo Zong-Liang; Zhu Chen-Xin; Xu Zhong-Guang; Liu Jing; Liu Ming

    2011-01-01

    In this paper, we investigate an Al 2 O 3 /HfSiO stack as the blocking layer of a metal—oxide—nitride—oxide—silicon-type (MONOS) memory capacitor. Compared with a memory capacitor with a single HfSiO layer as the blocking layer or an Al 2 O 3 /HfO 2 stack as the blocking layer, the sample with the Al 2 O 3 /HfSiO stack as the blocking layer shows high program/erase (P/E) speed and good data retention characteristics. These improved performances can be explained by energy band engineering. The experimental results demonstrate that the memory device with an Al 2 O 3 /HfSiO stack as the blocking layer has great potential for further high-performance nonvolatile memory applications. (interdisciplinary physics and related areas of science and technology)

  11. Electrical insulation properties of RF-sputtered LiPON layers towards electrochemical stability of lithium batteries

    OpenAIRE

    Vieira, E. M. F.; Ribeiro, J. F.; Silva, Maria Manuela; Barradas, N. P.; Alves, E.; Alves, A.; Correia, M. R.; Gonçalves, L. M.

    2016-01-01

    Electrochemical stability, moderate ionic conductivity and low electronic conductivity make the lithium phosphorous oxynitride (LiPON) electrolyte suitable for micro and nanoscale lithium batteries. The electrical and electrochemical properties of thin-film electrolytes can seriously compromise full battery performance. Here, radio-frequency (RF)-sputtered LiPON thin films were fabricated in nitrogen plasma under different working pressure conditions. With a slight decrease in ...

  12. High-surface-quality nanocrystalline InN layers deposited on GaN templates by RF sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Valdueza-Felip, Sirona; Naranjo, Fernando B.; Gonzalez-Herraez, Miguel [Grupo de Ingenieria Fotonica, Departamento de Electronica, Escuela Politecnica Superior, Universidad de Alcala, Campus Universitario, 28871 Alcala de Henares, Madrid (Spain); Lahourcade, Lise; Monroy, Eva [Equipe mixte CEA-CNRS-UJF, Nanophysique et Semiconducteurs, INAC/SP2M/PSC, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Fernandez, Susana [Departamento de Energias Renovables, Energia Solar Fotovoltaica, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Avda. Complutense 22, 28040 Madrid (Spain)

    2011-01-15

    We report a detailed study of the effect of deposition parameters on optical, structural, and morphological properties of InN films grown by reactive radio-frequency (RF) sputtering on GaN-on-sapphire templates in a pure nitrogen atmosphere. Deposition parameters under study are substrate temperature, RF power, and sputtering pressure. Wurtzite crystallographic structure with c-axis preferred growth orientation is confirmed by X-ray diffraction measurements. For the optimized deposition conditions, namely at a substrate temperature of 450 C and RF power of 30 W, InN films present a root-mean-square surface roughness as low as {proportional_to}0.4 nm, comparable to the underlying substrate. The apparent optical bandgap is estimated at 720 nm (1.7 eV) in all cases. However, the InN absorption band tail is strongly influenced by the sputtering pressure due to a change in the species of the plasma. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. The effect of growth surface morphology on the crystal structure and magnetic property of L1{sub 0} order PtFe layers deposited by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ding Wanyu, E-mail: dwysd_2000@163.com [Graduate School of Saitama Institute of Technology, Fukaya, Saitama 369-0293 (Japan) and School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028 (China); Ishiguro, Satoshi; Ogatsu, Ryo [Graduate School of Saitama Institute of Technology, Fukaya, Saitama 369-0293 (Japan); Ju, Dongying, E-mail: dyju@sit.ac.jp [Graduate School of Saitama Institute of Technology, Fukaya, Saitama 369-0293 (Japan)

    2012-08-01

    The Fe/Pt/Fe/Pt layers (Pt/Fe multilayer) were deposited on general glass substrate at room temperature by magnetron sputtering technique. Varying the deposition and post-annealing treatment parameters, the PtFe alloy (PtFe) layer with different crystal structures and magnetic properties were obtained at the interface between Fe and Pt layer. The characterization by X-ray diffraction (XRD) showed that the as-deposited Pt/Fe multilayer only contained pure Fe and Pt with body-centered and face-centered cubic structures, respectively. As-deposited Pt layer displayed (2 0 0) preferred orientation, and the columnar grains structure could be observed by the scanning electron microscopy. The PtFe layers with L1{sub 0} face-centered cubic structure could be formed at the interface between Pt and Fe layers by post-annealing the multilayers at 500 Degree-Sign C. In case of Pt/Fe multilayer deposited on smooth substrate, the larger columnar grains in Pt layer resulted in L1{sub 0} PtFe layers without any preferred orientation. While in case of Pt/Fe multilayer deposited on the rough substrate, the thinner columnar grains in Pt layer could induce L1{sub 0} PtFe layers with (2 0 0) preferred orientation. In this case, the vibrating sample magnetometer results indicated that, the magnetic coercivity in plane and out-of-plane model could reach 3.72 and 2.32 kOe, respectively. Based on above results, the L1{sub 0} structure Pt/Fe multilayer with satisfied magnetic properties could be prepared at low temperature by our simple route.

  14. Improving Performance via Blocking Layers in Dye-Sensitized Solar Cells Based on Nanowire Photoanodes.

    Science.gov (United States)

    Li, Luping; Xu, Cheng; Zhao, Yang; Chen, Shikai; Ziegler, Kirk J

    2015-06-17

    Electron recombination in dye-sensitized solar cells (DSSCs) results in significant electron loss and performance degradation. However, the reduction of electron recombination via blocking layers in nanowire-based DSSCs has rarely been investigated. In this study, HfO2 or TiO2 blocking layers are deposited on nanowire surfaces via atomic layer deposition (ALD) to reduce electron recombination in nanowire-based DSSCs. The control cell consisting of ITO nanowires coated with a porous shell of TiO2 by TiCl4 treatment yields an efficiency of 2.82%. The efficiency increases dramatically to 5.38% upon the insertion of a 1.3 nm TiO2 compact layer between the nanowire surface and porous TiO2 shell. This efficiency enhancement implies that porous sol-gel coatings on nanowires (e.g., via TiCl4 treatment) result in significant electron recombination in nanowire-based DSSCs, while compact coatings formed by ALD are more advantageous because of their ability to act as a blocking layer. By comparing nanowire-based DSSCs with their nanoparticle-based counterparts, we find that the nanowire-based DSSCs suffer more severe electron recombination from ITO due to the much higher surface area exposed to the electrolyte. While the insertion of a high band gap compact layer of HfO2 between the interface of the conductive nanowire and TiO2 shell improves performance, a comparison of the cell performance between TiO2 and HfO2 compact layers indicates that charge collection is suppressed by the difference in energy states. Consequently, the use of high band gap materials at the interface of conductive nanowires and TiO2 is not recommended.

  15. Low temperature pulsed direct current magnetron sputtering technique for single phase β-In2S3 buffer layers for solar cell applications

    Science.gov (United States)

    Karthikeyan, Sreejith; Hill, Arthur E.; Pilkington, Richard D.

    2017-10-01

    This work explores the possibilities of using the pulsed direct current (dc) magnetron sputtering (PDCMS) process to deposit an alternative to the cadmium sulphide buffer layer in copper indium gallium diselenide - based solar cells. The main problems with the CdS layer are its toxic nature and its deposition using a chemical bath technique. These factors make it difficult to incorporate into in-line production and significant effort has been expended to find a suitable alternative buffer layer with in-line manufacturing capability. Towards this aim, the material properties of an In2S3 film, sputtered from a powder target, have been investigated. Films were deposited at different substrate temperatures ranging from ;no additional substrate heating; to 250 °C. The deposition of a single phase β-In2S3 without substrate heating/annealing has not previously been reported. The films deposited by the ion-enhanced PdcMS technique without any additional heating were found to be single phase. The grain size increased with increase in substrate temperature. However, this led to a decrease in the sulphur content; as a result the band gap decreased. For solar cell applications, the CdS buffer layer (optical band gap ∼2.4 eV) needs to be replaced with a material which has a band gap wider than 2.4 eV for improved performance and reduction of absorption loss in the blue wavelength region. Ideally the band gap should be between 2.6 and 3.0 eV. Our PdcMS room temperature deposited In2S3 had a measured band gap of 2.77 eV.

  16. Adaptive Multi-Layered Space-Time Block Coded Systems in Wireless Environments

    KAUST Repository

    Al-Ghadhban, Samir

    2014-12-23

    © 2014, Springer Science+Business Media New York. Multi-layered space-time block coded systems (MLSTBC) strike a balance between spatial multiplexing and transmit diversity. In this paper, we analyze the block error rate performance of MLSTBC. In addition, we propose an adaptive MLSTBC schemes that are capable of accommodating the channel signal-to-noise ratio variation of wireless systems by near instantaneously adapting the uplink transmission configuration. The main results demonstrate that significant effective throughput improvements can be achieved while maintaining a certain target bit error rate.

  17. Heat-resistant thin film photoelectric converter with diffusion blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Takada, Jun; Yamaguchi, Minori; Tawada, Yoshihisa.

    1990-06-26

    The photoelectric converter of this invention comprises a semiconductor, an electrode, and a diffusion-blocking layer provided between the semiconductor and at least one electrode. An object of this invention is to provide a thin film photoelectric converter which has good heat resistance, in order to avoid the reduction in quality owing to the diffusion of metal or metallic compound from the electrode to the semiconductor layer, on the condition that the ohmic loss in the backing electrode and the reflection loss of light at the backing electrode are not increased. The component of the diffusion-blocking layer is selected from among such materials as metal silicides, silicide-forming metals, and metals from Groups IVA and VA of the periodic table. A preferable thickness of the diffusion-blocking layer is 5 to 500 angstroms. The semiconductor can be of the p-i-n, p-n, or Schottky type, and can be 0.02 to 100 {mu}m thick. For a semiconductor which comes into contact with the diffusion-blocking layer, n-type is preferable because it offers great improvements in the characteristics of the photoelectric converter. The electrode on the light-incident side is transparent and made of a metallic compound such as In{sub 2}O{sub 3}, SnO{sub 2}, Cd{sub x}SnO{sub y} (x=0.5 to 2, y=2 to 4) or the like. The backing electrode material is selected to have a suitable conductivity and reflectivity; such materials include Ag, Au, Al or Cu. The invention also discloses a method of preparing the thick film photoelectric converter, and examples are provided to illustrate the preparation of various embodiments of the invention. 2 figs., 1 tab.

  18. Atomic layer deposition of high performance ultrathin TiO₂ blocking layers for dye-sensitized solar cells.

    Science.gov (United States)

    Kim, Do Han; Woodroof, Mariah; Lee, Kyoungmi; Parsons, Gregory N

    2013-06-01

    Dye-sensitized solar cells (DSSCs) often use a thin insulating or semiconducting layer (typically TiO₂) between the transparent conductive oxide and the mesoporous TiO₂ to block electron/hole recombination at the conducting oxide/electrolyte interface. The blocking layer (BL) is essential to maintain efficient charge generation under low light conditions, at which DSSCs perform well compared to common semiconductor-based photovoltaic devices. In this work, we show that atomic layer deposition (ALD) can produce ultrathin (ALD BLs are the thinnest optimized DSSC BLs reported to date. The BL retards the open-circuit voltage decay and extends the electron lifetime from ≈0.2 s to more than 10 s at 0.3 V, confirming that the ALD films significantly impede photogenerated charge recombination. By preparing BLs through other deposition techniques, we directly demonstrate that ALD results in better performance, even with thinner films, which is ascribed to the lower pinhole density of ALD materials. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Effect of the laser sputtering parameters on the orientation of a cerium oxide buffer layer on sapphire and the properties of a YBa2Cu3Ox superconducting film

    DEFF Research Database (Denmark)

    Mozhaev, P. B.; Ovsyannikov, G. A.; Skov, Johannes

    1999-01-01

    The effect of the laser sputtering parameters on the crystal properties of CeO2 buffer layers grown on a (1 (1) under bar 02) sapphire substrate and on the properties of superconducting YBa2Cu3Ox thin films are investigated. It is shown that (100) and (111) CeO2 growth is observed, depending on t...... on the sputtering conditions. A buffer layer with the desired unidirectional orientation can be obtained by varying the heater temperature, the pressure in the chamber, and the energy density of the laser beam at the target. (C) 1999 American Institute of Physics....

  20. Intermixing of InGaAs/GaAs quantum wells and quantum dots using sputter-deposited silicon oxynitride capping layers

    Energy Technology Data Exchange (ETDEWEB)

    McKerracher, Ian; Fu Lan; Hoe Tan, Hark; Jagadish, Chennupati [Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia)

    2012-12-01

    Various approaches can be used to selectively control the amount of intermixing in III-V quantum well and quantum dot structures. Impurity-free vacancy disordering is one technique that is favored for its simplicity, however this mechanism is sensitive to many experimental parameters. In this study, a series of silicon oxynitride capping layers have been used in the intermixing of InGaAs/GaAs quantum well and quantum dot structures. These thin films were deposited by sputter deposition in order to minimize the incorporation of hydrogen, which has been reported to influence impurity-free vacancy disordering. The degree of intermixing was probed by photoluminescence spectroscopy and this is discussed with respect to the properties of the SiO{sub x}N{sub y} films. This work was also designed to monitor any additional intermixing that might be attributed to the sputtering process. In addition, the high-temperature stress is known to affect the group-III vacancy concentration, which is central to the intermixing process. This stress was directly measured and the experimental values are compared with an elastic-deformation model.

  1. Effect of substrate composition on atomic layer deposition using self-assembled monolayers as blocking layers

    International Nuclear Information System (INIS)

    Zhang, Wenyu; Engstrom, James R.

    2016-01-01

    The authors have examined the effect of two molecules that form self-assembled monolayers (SAMs) on the subsequent growth of TaN x by atomic layer deposition (ALD) on two substrate surfaces, SiO 2 and Cu. The SAMs that the authors have investigated include two vapor phase deposited, fluorinated alkyl silanes: Cl 3 Si(CH 2 ) 2 (CF 2 ) 5 CF 3 (FOTS) and (C 2 H 5 O) 3 Si(CH 2 ) 2 (CF 2 ) 7 CF 3 (HDFTEOS). Both the SAMs themselves and the TaN x thin films, grown using Ta[N(CH 3 ) 2 ] 5 and NH 3 , were analyzed ex situ using contact angle, spectroscopic ellipsometry, x-ray photoelectron spectroscopy (XPS), and low energy ion-scattering spectroscopy (LEISS). First, the authors find that both SAMs on SiO 2 are nominally stable at T s  ∼ 300 °C, the substrate temperature used for ALD, while on Cu, the authors find that HDFTEOS thermally desorbs, while FOTS is retained on the surface. The latter result reflects the difference in the head groups of these two molecules. The authors find that both SAMs strongly attenuate the ALD growth of TaN x on SiO 2 , by about a factor of 10, while on Cu, the SAMs have no effect on ALD growth. Results from LEISS and XPS are decisive in determining the nature of the mechanism of growth of TaN x on all surfaces. Growth on SiO 2 is 2D and approximately layer-by-layer, while on the surfaces terminated by the SAMs, it nucleates at defect sites, is islanded, and is 3D. In the latter case, our results support growth of the TaN x thin film over the SAM, with a considerable delay in formation of a continuous thin film. Growth on Cu, with or without the SAMs, is also 3D and islanded, and there is also a delay in the formation of a continuous thin film as compared to growth on SiO 2 . These results highlight the power of coupling measurements from both LEISS and XPS in examinations of ultrathin films formed by ALD

  2. Double-Layer Compressive Sensing Based Efficient DOA Estimation in WSAN with Block Data Loss.

    Science.gov (United States)

    Sun, Peng; Wu, Liantao; Yu, Kai; Shao, Huajie; Wang, Zhi

    2017-07-22

    Accurate information acquisition is of vital importance for wireless sensor array network (WSAN) direction of arrival (DOA) estimation. However, due to the lossy nature of low-power wireless links, data loss, especially block data loss induced by adopting a large packet size, has a catastrophic effect on DOA estimation performance in WSAN. In this paper, we propose a double-layer compressive sensing (CS) framework to eliminate the hazards of block data loss, to achieve high accuracy and efficient DOA estimation. In addition to modeling the random packet loss during transmission as a passive CS process, an active CS procedure is introduced at each array sensor to further enhance the robustness of transmission. Furthermore, to avoid the error propagation from signal recovery to DOA estimation in conventional methods, we propose a direct DOA estimation technique under the double-layer CS framework. Leveraging a joint frequency and spatial domain sparse representation of the sensor array data, the fusion center (FC) can directly obtain the DOA estimation results according to the received data packets, skipping the phase of signal recovery. Extensive simulations demonstrate that the double-layer CS framework can eliminate the adverse effects induced by block data loss and yield a superior DOA estimation performance in WSAN.

  3. Investigations of RF magnetron sputtered CZTS absorber layer thin films prepared using sulfur induced binary targets without sulfurization

    Science.gov (United States)

    Balaji, G.; Balasundaraprabhu, R.; Prasanna, S.; Prabavathy, N.; McIlroy, D. N.; Kannan, M. D.

    2018-01-01

    Thin films of copper zinc tin sulfide (CZTS), a quaternary semiconductor, was deposited onto well-cleaned soda lime glass substrates using binary sulfur based sputtering targets - copper sulfide (CuS), zinc sulfide (ZnS), and tin sulfide (SnS) by RF Magnetron Sputtering at 300 °C. The stacking order of ZnS/CuS/SnS was used to deposit CZTS thin films. The composition of CZTS thin films were confirmed using X- Ray photoelectron spectroscopy (XPS) and the atomic ratio of the individual elements were quantitatively estimated. X-ray diffraction (XRD) studies were used to understand the CZTS phase formation and the presence of CZTS kesterite phase along direction was detected with the secondary phase of SnS and ZnS. XRD results were validated with Raman results were the presence of CZTS and SnS was corroborated. The optical properties of CZTS thin films were studied using UV-Vis-NIR spectrophotometer where the optical band gap was 1.46 eV and as well as other optical parameters such as interference and optical band gap were ascertained and the results are discussed.

  4. Interface transparency and proximity effect in Nb/Cu triple layers realized by sputtering and molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Tesauro, A; Aurigemma, A; Cirillo, C; Prischepa, S L; Salvato, M; Attanasio, C [Dipartimento di Fisica ' E R Caianiello' and INFM-Laboratorio Regionale Supermat, Universita degli Studi di Salerno, Baronissi, Sa, I-84081 (Italy)

    2005-01-01

    We have investigated, in the framework of the proximity effect theory, the interface transparency T between Nb and Cu in the case of high quality Nb/Cu trilayers fabricated by molecular beam epitaxy (MBE) and sputtering deposition techniques. The obtained T values do not seem to be strongly influenced by the fabrication methods but more by the intrinsic properties of the two metals; a slightly higher value for T has even been deduced for the MBE prepared samples. The proximity effect in these samples has also been studied in the presence of an external magnetic field. In the parallel configuration a significant shift towards lower values of the 2D-3D crossover temperature has been observed for MBE samples, in good agreement with very recent theoretical predictions. In the perpendicular case a positive curvature of the temperature dependence of the upper critical field has been detected, which was less pronounced for sputtered samples. Both the effects have been observed only for trilayers with low Nb thickness (<600 A) which confirms the crucial influence of the interface transparency on the values of the upper critical field in such samples.

  5. Development of ZnO:Al-based transparent contacts deposited at low-temperature by RF-sputtering on InN layers

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, S. [Departamento de Energias Renovables, Energia Solar Fotovoltaica, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Avda. Complutense 22, 28040 Madrid (Spain); Naranjo, F.B.; Valdueza-Felip, S. [Grupo de Ingenieria Fotonica, Departamento de Electronica, Escuela Politecnica Superior, Universidad de Alcala Campus Universitario, 28871 Alcala de Henares, Madrid (Spain); Abril, O. de [ISOM and Departamento de Fisica Aplicada, Escuela Tecnica Superior de Ingenieros de Telecomunicacion, Universidad Politenica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2012-03-15

    Nitride semiconductors (Al,Ga,In)N attain material properties that make them suitable for photovoltaic and optoelectronics devices to be used in hard environments. These properties include an energy gap continuously tuneable within the energy range of the solar spectrum, a high radiation resistance and thermal stability. The developing of efficient devices requires contacts with low resistivity and high transmittance in visible region. ZnO:Al (AZO) emerges as a feasible candidate for transparent contact to nitride semiconductors, taking advantage of its low resistivity, high transparency in visible wavelengths and a very low lattice mismatch with respect to nitride semiconductors. This work presents a study of the applications of AZO films deposited at low-temperature by RF magnetron sputtering as transparent contact for InN layers. The optimization of AZO conditions deposition lead to the obtaining of contacts which shows an ohmic behaviour for the as-deposited layer, regardless the thickness of the ZnO:Al contact layer. Specific contact resistances of 1.6 {omega}.cm{sup 2} were achieved for the contact with 90 nm thick ZnO:Al layer without any post-deposition treatment (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Templating of cylindrical and spherical block copolymer microdomains by layered silicates

    Science.gov (United States)

    Silva, Adriana S.; Mitchell, Cynthia A.; Fu Tse, Mun; Wang, Hsien-C.; Krishnamoorti, Ramanan

    2001-10-01

    The influence of a highly anisotropic layered silicate (organically modified montmorillonite) in directing the mesoscopic self-assembly of a block copolymer blend is studied as a model for the development and tailoring of templated inorganic-organic hybrid materials. The potential for nanometer thick layers to induce large-scale mesoscopic ordering of cylindrical and spherical microdomains in asymmetric block copolymers is studied using a combination of rheology, electron microscopy, and small angle neutron scattering. Spherical microdomains arranged on a bcc lattice are templated by the anisotropic layered silicate and the kinetics of their growth are dramatically accelerated by the presence of even 0.1 wt.% (0.04 vol.%) of the filler. However, for cylindrical microdomain ordering, the kinetics are essentially unaffected by the addition of layered silicates and the development of three-dimensional mesoscopic order is possibly even disrupted. These results suggest that for the development of three-dimensional well-ordered nanostructures, the surface defining the pattern has to be significantly larger than the leading dimension of the structure being templated.

  7. Block Copolymer-Tuned Fullerene Electron Transport Layer Enhances the Efficiency of Perovskite Photovoltaics.

    Science.gov (United States)

    Lin, Hsi-Kuei; Su, Yu-Wei; Chen, Hsiu-Cheng; Huang, Yi-Jiun; Wei, Kung-Hwa

    2016-09-21

    In this study, we enhanced the power conversion efficiency (PCE) of perovskite solar cells by employing an electron transfer layer (ETL) comprising [6,6]phenyl-C61-butyric acid methyl ester (PC61BM) and, to optimize its morphology, a small amount of the block copolymer polystyrene-b-poly(ethylene oxide) (PS-b-PEO), positioned on the perovskite active layer. When incorporating 0.375 wt % PS-b-PEO into PC61BM, the PCE of the perovskite photovoltaic device increased from 9.4% to 13.4%, a relative increase of 43%, because of a large enhancement in the fill factor of the device. To decipher the intricate morphology of the ETL, we used synchrotron grazing-incidence small-angle X-ray scattering for determining the PC61BM cluster size, atomic force microscopy and scanning electron microscopy for probing the surface, and transmission electron microscopy for observing the aggregation of PC61BM in the ETL. We found that the interaction between PS-b-PEO and PC61BM resulted in smaller PC61BM clusters that further aggregated into dendritic structures in some domains, a result of the similar polarities of the PS block and PC61BM; this behavior could be used to tune the morphology of the ETL. The optimal PS-b-PEO-mediated PC61BM cluster size in the ETL was 17 nm, a large reduction from 59 nm for the pristine PC61BM layer. This approach of incorporating a small amount of nanostructured block copolymer into a fullerene allowed us to effectively tune the morphology of the ETL on the perovskite active layer and resulted in enhanced fill factors of the devices and thus their device efficiency.

  8. Surface characterization of Zr/Ti/Nb tri-layered films deposited by magnetron sputtering on Si(111) and stainless steel substrates

    Energy Technology Data Exchange (ETDEWEB)

    Tallarico, Denise A.; Gobbi, Angelo L.; Filho, Pedro I. Paulin; Galtayries, Anouk; Nascente, Pedro A. P. [Federal University of Sao Carlos, Department of Materials Engineering, Via Washington Luis km 235, CEP 13565-905, Sao Carlos, SP (Brazil); Brazilian Synchrotron Light Laboratory, Microfabrication Laboratory, Rua Giuseppe Maximo Scolfaro 10.000, CEP 13083-100, Campinas, SP (Brazil); Federal University of Sao Carlos, Department of Materials Engineering, Via Washington Luis km 235, CEP 13565-905, Sao Carlos, SP (Brazil); Ecole Nationale Superieure de Chimie de Paris (Chimie ParisTech), Laboratoire de Physico-Chimie des Surfaces, UMR CNRS 7045, F-75231 Paris cedex 05 (France); Federal University of Sao Carlos, Department of Materials Engineering, Via Washington Luis km 235, CEP 13565-905, Sao Carlos, SP (Brazil)

    2012-09-15

    Among metallic materials, commercially pure titanium and titanium alloys are very often used as biomaterials for implants. Among these alloys, titanium-aluminum-vanadium alloy Ti-6 A-4 V is one of the most commonly used due to its excellent biocompatibility and ability to allow bone-implant integration. A new class of Ti alloys employs Zr for solid-solution hardening and Nb as {beta}-phase stabilizer. Metals such as Ti, Nb, and Zr-known as valve metals-usually have their surfaces covered by a thin oxide film that forms spontaneously in air. This oxide film constitutes a barrier between the metal and the medium. The Ti-Nb-Zr alloys have mechanical and corrosion resistance characteristics which make them suitable for use as implants. Tri-layered films of Ti-Nb-Zr were deposited on both Si(111) and stainless steel (SS) substrates using dc magnetron sputtering equipment, under an argon atmosphere according to the following methodology: a 100 nm thick layer of Nb was deposited on the substrate, followed by a 200 nm thick layer of Ti, and finally a 50 nm thick layer of Zr, on top of the multilayer stack. The morphology and chemical composition of the films were analyzed by atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). AFM images showed that the Zr/Ti/Nb tri-layer films presented nanostructured grains and low roughness. The ToF-SIMS depth profiles confirmed the formation of a three-layered film on Si(111) with well-defined and sharp interfaces between the layers, while the deposition on the stainless steel substrate caused slight intermixing at the different alloy/Nb, Nb/Ti and Ti/Zr interfaces, reflecting the greater roughness of the raw substrate. The XPS results for the Zr/Ti/Nb layers deposited on Si(111) and SS confirmed that the outermost layer consisted of Zr only, with a predominance of ZrO{sub 2}, as the metal layer is passivated in air. An oxidation treatment of 1000 Degree

  9. Sputtering measurements using a quartz crystal microbalance as a catcher

    Science.gov (United States)

    Berger, Bernhard M.; Szabo, Paul S.; Stadlmayr, Reinhard; Aumayr, Friedrich

    2017-09-01

    A quartz crystal microbalance (QCM) catcher setup for sputter yield measurements is described. In this setup a QCM is placed next to the sputter target and acts as a catcher for sputtered material. The sputter yield evaluation relies on assumptions about the angular distribution of sputtered particles and reflected primary projectiles taken from simulations as well as on the knowledge of the sticking coefficient. To test this new setup a second QCM with a Au layer was used as a sputter target. The measured ratio between target and catcher signal is well reproduced in the simulations demonstrating the feasibility of reconstructing the sputtering yield from the catcher signal.

  10. Insertion of NiO electron blocking layer in fabrication of GaN-organic heterostructures

    Science.gov (United States)

    Li, Junmei; Guo, Wei; Jiang, Jie'an; Gao, Pingqi; Bo, Baoxue; Ye, Jichun

    2018-03-01

    We report the fabrication of a NiO thin film on top of an n-type GaN epitaxial layer. The electron-blocking capability of NiO in a hybrid organic/inorganic heterostructure consisting of n-GaN/NiO/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is discussed. Surface morphology, crystallography orientation, bandgap, and fermi level information of NiO films were investigated in detail. A rectifying property consistent with the proposed band diagram was observed in the current-voltage measurement. Theoretical analysis also demonstrated the effective electron blocking due to band alignment and a more balanced carrier distribution inside the GaN region with NiO inserted into the n-GaN/PEDOT:PSS heterostructure. This work provides a promising approach to the fabrication of high-efficiency hybrid optoelectronic devices.

  11. Natural Rubber Modification For Upper Layer Of Rubberized Asphalt Paving Block AS Shock Absorber

    OpenAIRE

    Nasruddin, Nasruddin

    2017-01-01

    The research of rubber compounding modification for upper layer of rubberized asphalt paving block as shock absorber using natural rubber, styrene butadiene rubber (SBR) as synthetic rubber, fly ash as filler and also vegetable oil as plasticizer has been conducted. The research design was varying the filler Si-69, fly ash and palm oil. The five formulas A, B, C, D, and E designed by varying the amount of Si-69 (48.5; 50.75; 53.00; 55.25; and 57.50) phr; coal fly ash (4.75, 7.00, 9.25, 11.50 ...

  12. ZnS/Al2S3 Layer as a Blocking Layer in Quantum Dot Sensitized Solar Cells

    Science.gov (United States)

    Vafapoor, Borzoo; Fathi, Davood; Eskandari, Mehdi

    2018-03-01

    In this research, the effect of treatment of the CdS/CdSe sensitized ZnO photoanode by ZnS, Al2S3, and ZnS/Al2S3 nanoparticles as a barrier layer on the performance of quantum dot sensitized solar cell is investigated. Current density-voltage ( J- V) characteristics show that cell efficiency is enhanced from 3.62% to 4.82% with treatment of a CdS/CdSe/ZnS sensitized ZnO photoanode by Al2S3 nanoparticles. In addition, short- circuit current density ( J sc) is increased from 11.5 mA/cm2 to 14.8 mA/cm2. The results extracted from electrochemical impedance spectroscopy indicate that charge transfer resistance ( R ct) in photoanode/electrolyte interfaces decreases with deposition of Al2S3 nanoparticles on CdS/CdSe/ZnS sensitized ZnO photoanodes, while the chemical capacitance of photoanode ( C μ ) and electron lifetime ( t n) increase. Also, results revealed that cell performance is considerably decreased with the treatment of the AL2S3 blocking layer incorporated between ZnO nanorods and CdS/CdSe QDs.

  13. Boundary layers of aqueous surfactant and block copolymer solutions against hydrophobic and hydrophilic solid surfaces

    International Nuclear Information System (INIS)

    Steitz, Roland; Schemmel, Sebastian; Shi Hongwei; Findenegg, Gerhard H

    2005-01-01

    The boundary layer of aqueous surfactants and amphiphilic triblock copolymers against flat solid surfaces of different degrees of hydrophobicity was investigated by neutron reflectometry (NR), grazing incidence small angle neutron scattering (GISANS) and atomic force microscopy (AFM). Solid substrates of different hydrophobicities were prepared by appropriate surface treatment or by coating silicon wafers with polymer films of different chemical natures. For substrates coated with thin films (20-30 nm) of deuterated poly(styrene) (water contact angle θ w ∼ 90), neutron reflectivity measurements on the polymer/water interface revealed a water depleted liquid boundary layer of 2-3 nm thickness and a density about 90% of the bulk water density. No pronounced depletion layer was found at the interface of water against a less hydrophobic polyelectrolyte coating (θ w ∼ 63). It is believed that the observed depletion layer at the hydrophobic polymer/water interface is a precursor of the nanobubbles which have been observed by AFM at this interface. Decoration of the polymer coatings by adsorbed layers of nonionic C m E n surfactants improves their wettability by the aqueous phase at surfactant concentrations well below the critical micellar concentration (CMC) of the surfactant. Here, GISANS experiments conducted on the system SiO 2 /C 8 E 4 /D 2 O reveal that there is no preferred lateral organization of the C 8 E 4 adsorption layers. For amphiphilic triblock copolymers (PEO-PPO-PEO) it is found that under equilibrium conditions they form solvent-swollen brushes both at the air/water and the solid/water interface. In the latter case, the brushes transform to uniform, dense layers after extensive rinsing with water and subsequent solvent evaporation. The primary adsorption layers maintain properties of the precursor brushes. In particular, their thickness scales with the number of ethylene oxide units (EO) of the block copolymer. In the case of dip-coating without

  14. Surface and optical properties of indium tin oxide layer deposition by RF magnetron sputtering in argon atmosphere

    Science.gov (United States)

    Yudar, H. Hakan; Korkmaz, Şadan; Özen, Soner; Şenay, Volkan; Pat, Suat

    2016-08-01

    This study focused on the characterization and properties of transparent and conductive indium tin oxide (ITO) thin films deposited in argon atmosphere. ITO thin films were coated onto glass substrates by radio frequency (RF) magnetron sputtering technique at 75 and 100 W RF powers. Structural characteristics of producing films were investigated through X-ray diffraction analysis. UV-Vis spectrophotometer and interferometer were used to determine transmittance, absorbance and reflectance values of samples. The surface morphology of the films was characterized by atomic force microscope. The calculated band gaps were 3.8 and 4.1 eV for the films at 75 and 100 W, respectively. The effect of RF power on crystallinity of prepared films was explored using mentioned analysis methods. The high RF power caused higher poly crystallinity in the produced samples. The thickness and refractive index values for all samples increased respect to an increment of RF power and were calculated as 20, 50 nm and 1.71, 1.86 for samples at 75 and 100 W, respectively. Finally, the estimated grain sizes for all prepared films decreased with increasing of 2 θ degrees, and the number of crystallite per unit volume was calculated. It was found that nearly all properties including sheet resistance and resistivity depend on the RF power.

  15. Effects of V2O3 buffer layers on sputtered VO2 smart windows: Improved thermochromic properties, tunable width of hysteresis loops and enhanced durability

    Science.gov (United States)

    Long, Shiwei; Cao, Xun; Sun, Guangyao; Li, Ning; Chang, Tianci; Shao, Zewei; Jin, Ping

    2018-05-01

    Vanadium dioxide (VO2) is one of the most well-known thermochromic materials, which exhibits a notable optical change from transparent to reflecting in the infrared region upon a metal-insulator phase transition. For practical applications, VO2 thin films should be in high crystalline quality to obtain a strong solar modulation ability (ΔTsol). Meanwhile, narrow hysteresis loops and robust ambient durability are also indispensable for sensitivity and long-lived utilization, respectively. In this work, a series of high-quality V2O3/VO2 bilayer structures were grown on quartz glass substrates by reactive magnetron sputtering. Basically, the bottom V2O3 acts as the buffer layer to improve the crystallinity of the top VO2, while the VO2 serves as the thermochromic layer to guarantee the solar modulation ability for energy-saving. We observed an obvious increase in ΔTsol of 76% (from 7.5% to 13.2%) for VO2 films after introducing V2O3 buffer layers. Simultaneously, a remarkable reduction by 79% (from 21.9 °C to 4.7 °C) in width of hysteresis loop was obtained when embedding 60 nm V2O3 buffer for 60 nm VO2. In addition, VO2 with non-stoichiometry of V2O3±x buffer demonstrates a broadening hysteresis loops width, which is derived from the lattice distortion caused by lattice imperfection. Finally, durability of VO2 has been significantly improved due to positive effects of V2O3 buffer layer. Our results lead to a comprehensive enhancement in crystallinity of VO2 and shed new light on the promotion of thermochromic property by homologous oxides for VO2.

  16. Characterization of ALD Processed Gallium Doped TiO2 Hole Blocking Layer in an Inverted Organic Solar Cell

    Science.gov (United States)

    Lee, Eun Ju; Ryu, Sang Ouk

    2017-02-01

    To improve power conversion efficiency (PCE) of inverted structure organic solar cells a buffer layer, a hole blocking layer (HBL) was introduced between cathode and active photovoltaic layer. Gallium (Ga) doped TiO2 as a HBL was fabricated by means of atomic layer deposition. X-ray photoelectron spectroscopy showed the highest Ga-Ti complex binding characteristics was achieved at 5% doping concentration. Gallium doped TiO2 layer exhibited over 94% of optical transmittance at the process temperature of 200°C. The resulting PCE of inverted structure organic solar cell having 5% doping in the hole block layer was 2.7%. The PCE was improved 35% compared to the cell without gallium doping.

  17. Optical and electrical characteristics of GaN vertical light emitting diode with current block layer

    International Nuclear Information System (INIS)

    Guo Enqing; Liu Zhiqiang; Wang Liancheng; Yi Xiaoyan; Wang Guohong

    2011-01-01

    A GaN vertical light emitting diode (LED) with a current block layer (CBL) was investigated. Vertical LEDs without a CBL, with a non-ohmic contact CBL and with a silicon dioxide CBL were fabricated. Optical and electrical tests were carried out. The results show that the light output power of vertical LEDs with a non-ohmic contact CBL and with a silicon dioxide CBL are 40.6% and 60.7% higher than that of vertical LEDs without a CBL at 350 mA, respectively. The efficiencies of vertical LEDs without a CBL, with a non-ohmic contact CBL and with a silicon dioxide CBL drop to 72%, 78% and 85.5% of their maximum efficiency at 350 mA, respectively. Moreover, vertical LEDs with a non-ohmic contact CBL have relatively superior anti-electrostatic ability. (semiconductor devices)

  18. Charge trap flash memory using ferroelectric materials as a blocking layer

    Science.gov (United States)

    Seo, Yujeong; An, Ho-Myoung; Yeong Song, Min; Geun Kim, Tae

    2012-04-01

    In this paper, we propose a charge-trap flash memory device using a ferroelectric material, Sr0.7Bi2.3Nb2O9 (SBN), with spontaneous polarization as a blocking layer. This device consists of metal/SBN/nitride/oxide/silicon and has an advantage in the carrier injection into the nitride from the silicon due to polarization charges formed in the ferroelectric material. Compared to conventional metal/oxide/nitride/oxide/silicon memory devices, the proposed devices showed a larger memory window (7 V), faster program/erase (P/E) speeds (100/500 μs), and higher endurance (105 P/E cycles) with comparable retention properties.

  19. Comparative study of CAVET with dielectric and p-GaN gate and Mg ion-implanted current blocking layer

    Science.gov (United States)

    Mandal, Saptarshi; Agarwal, Anchal; Ahmadi, Elaheh; Mahadeva Bhat, K.; Laurent, Matthew A.; Keller, Stacia; Chowdhury, Srabanti

    2017-08-01

    In this work, a study of two different types of current aperture vertical electron transistor (CAVET) with ion-implanted blocking layer are presented. The device fabrication and performance limitation of a CAVET with a dielectric gate is discussed, and the breakdown limiting structure is evaluated using on-wafer test structures. The gate dielectric limited the device breakdown to 50V, while the blocking layer was able to withstand over 400V. To improve the device performance, an alternative CAVET structure with a p-GaN gate instead of dielectric is designed and realized. The pGaN gated CAVET structure increased the breakdown voltage to over 400V. Measurement of test structures on the wafer showed the breakdown was limited by the blocking layer instead of the gate p-n junction.

  20. A Study on Field Emission Characteristics of Planar Graphene Layers Obtained from a Highly Oriented Pyrolyzed Graphite Block.

    KAUST Repository

    Lee, Seok Woo

    2009-07-12

    This paper describes an experimental study on field emission characteristics of individual graphene layers for vacuum nanoelectronics. Graphene layers were prepared by mechanical exfoliation from a highly oriented pyrolyzed graphite block and placed on an insulating substrate, with the resulting field emission behavior investigated using a nanomanipulator operating inside a scanning electron microscope. A pair of tungsten tips controlled by the nanomanipulator enabled electric connection with the graphene layers without postfabrication. The maximum emitted current from the graphene layers was 170 nA and the turn-on voltage was 12.1 V.

  1. Multifunctional alumina/titania hybrid blocking layer modified nanocrystalline titania films as efficient photoanodes in dye sensitized solar cells

    Science.gov (United States)

    Wang, Changlei; Yu, Zhenhua; Bu, Chenghao; Liu, Pei; Bai, Sihang; Liu, Chang; Kondamareddy, Kiran Kumar; Sun, Weiwei; Zhan, Kan; Zhang, Kun; Guo, Shishang; Zhao, Xingzhong

    2015-05-01

    A facile way of fabricating efficient blocking layer on mesoporous TiO2 film of dye-sensitized solar cells (DSSCs) is demonstrated here for the first time. Al2O3 and TiO2 are combined together to form a blocking layer. A simple spin coating technique is employed which is a versatile and low-cost method over the atomic layer deposition (ALD) technique. Multifunctional alumina/titania (Al2O3/TiO2) hybrid overlayer is prepared on traditional TiO2 nanocrystalline thin film surface, through sequential deposition of AlCl3·6H2O and TiCl4 precursor solutions followed by sintering at 500 °C for 30 min. Al2O3 effectively plays its role in retarding interfacial recombination of electrons and improving open circuit potential (Voc), while the tiny TiO2 clusters synthesized from TiCl4 treatment act as electron transporting channels to facilitate electron diffusion which leads to enhanced photocurrent (Jsc). Compared to the device without blocking layer, the DSSCs assembled with Al2O3/TiO2 hybrid blocking layer showed improvement in Jsc (from 13.09 mA/cm2 to 16.90 mA/cm2) as well as in Voc (from 0.72 V to 0.73 V) resulting a much better conversion efficiency of 8.60%.

  2. Direct formation of a current collector layer on a partially reduced graphite oxide film using sputter-assisted metal deposition to fabricate high-power micro-supercapacitor electrodes

    Science.gov (United States)

    Byun, Segi; Yu, Jin

    2016-03-01

    When a reduced graphite oxide (RGO) freestanding film is fabricated on a supercapacitor cell via compression onto a current collector, there are gaps between the film and the current collector, even if the cell is carefully assembled. These gaps can induce increases in the electrical series resistance (ESR) of the cell, resulting in degradation of the cell's electrochemical performance. Here, to effectively reduce the ESR of the supercapacitor, metal sputtering deposition is introduced. This enables the direct formation of the current collector layer on a partially reduced GO (pRGO) film, the model system. Using metal sputtering, a nickel (Ni) layer with a thickness formed on the pRGO film. The pRGO film sustains its film form with high packing density (∼1.31 g cm-3). Furthermore, the Ni-sputtered pRGO film with optimized Ni thickness exhibits remarkable enhancement of its electrochemical performance. This includes a superior rate capability and semi-permanent cycle life compared with the untreated pRGO film. This is due to the significant decrease in the ESR of the film.

  3. Enhancing Carrier Injection Using Graded Superlattice Electron Blocking Layer for UVB Light-Emitting Diodes

    KAUST Repository

    Janjua, Bilal

    2014-12-01

    We have studied enhanced carrier injection by having an electron blocking layer (EBL) based on a graded superlattice (SL) design. Here, we examine, using a selfconsistent 6 × 6 k.p method, the energy band alignment diagrams under equilibrium and forward bias conditions while also considering carrier distribution and recombination rates (Shockley-Read-Hall, Auger, and radiative recombination rates). The graded SL is based on AlxGa1-xN (larger bandgap) Al0:5Ga0:5N (smaller bandgap) SL, where x is changed from 0.8 to 0.56 in steps of 0.06. Graded SL was found to be effective in reducing electron leakage and enhancing hole injection into the active region. Due to our band engineering scheme for EBL, four orders-of-magnitude enhancement were observed in the direct recombination rate, as compared with the conventional bulk EBL consisting of Al0:8Ga0:2N. An increase in the spatial overlap of carrier wavefunction was obtained due to polarization-induced band bending in the active region. An efficient single quantum-well ultraviolet-B light-emitting diode was designed, which emits at 280 nm. This is the effective wavelength for water disinfection application, among others.

  4. Growth of monolithic full-color GaN-based LED with intermediate carrier blocking layers

    International Nuclear Information System (INIS)

    El-Ghoroury, Hussein S.; Yeh, Milton; Chen, J. C.; Li, X.; Chuang, Chih-Li

    2016-01-01

    Specially designed intermediate carrier blocking layers (ICBLs) in multi-active regions of III-nitride LEDs were shown to be effective in controlling the carrier injection distribution across the active regions. In principle, the majority of carriers, both holes and electrons, can be guided into targeted quantum wells and recombine to generate light of specific wavelengths at controlled current-densities. Accordingly we proposed and demonstrated a novel monolithic InGaN-based LED to achieve three primary colors of light from one device at selected current densities. This LED structure, which has three different sets of quantum wells separated with ICBLs for three primary red-green-blue (RGB) colors, was grown by metal-organic chemical vapor deposition (MOCVD). Results show that this LED can emit light ranging from 460 to 650 nm to cover the entire visible spectrum. The emission wavelength starts at 650 nm and then decreases to 460 nm or lower as the injection current increases. In addition to three primary colors, many other colors can be obtained by color mixing techniques. To the best of our knowledge, this is the first demonstration of monolithic full-color LED grown by a simple growth technique without using re-growth process.

  5. On electrode pinning and charge blocking layers in organic solar cells

    Science.gov (United States)

    Magen, Osnat; Tessler, Nir

    2017-05-01

    We use device modelling for studying the losses introduced by metallic electrodes in organic solar cells' device structure. We first discuss the inclusion of pinning at the integer charge transfer state in device models, with and without using the image charge potential. In the presence of disorder, the space charge introduced due to the image potential enhances the pinning by more than 0.2 eV. The explicit introduction of the image potential creates band-gap narrowing at the contact, thus affecting both dark leakage current and photo conversion efficiency. We find that there are two regimes in which the contacts may limit the performance. For low (moderate) barriers, the contacts introduce minority carrier recombination at the contacts that adds to the bulk recombination channels. Only for high barriers, the contacts directly limit the open circuit voltage and impose a value that is equal to the contact's energy difference. Examining the device structures with blocking layers, we find that these are mainly useful for the low to moderate contacts' barriers and that for the high barrier case, the enhancement of open circuit voltage may be accompanied by the introduction of serial resistance or S shape.

  6. Increase of the blocking temperature of Fe–Ag granular multilayers with increasing number of the layers

    Energy Technology Data Exchange (ETDEWEB)

    Balogh, Judit [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Kaptás, Dénes, E-mail: kaptas.denes@wigner.mta.hu [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Kiss, László F. [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Dézsi, István [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Nakanishi, Akio [Department of Physics, Shiga University of Medical Science, Shiga 520-2192 (Japan); Devlin, Eamonn; Vasilakaki, Marianna; Margaris, George; Trohidou, Kalliopi N. [Institute of Nanoscience and Nanotechnology, NCSR “Demokritos”, Aghia Paraskevi, 15310 Athens (Greece)

    2016-03-01

    Multilayers of 0.4 nm Fe and 5 nm Ag with repetition number, n=1, 2, 5, 10 and 20 were prepared by vacuum evaporation onto Si wafer. The blocking temperature was determined by measuring the field cooled and zero field cooled magnetization curves with a SQUID magnetometer and it was found to increase by almost an order of magnitude from around 20 K for the single Fe layer sample up to around 160 K for n=20. Significant increase of the average size of the superparamagnetic Fe grains by increasing the number of the Fe layers was excluded by conversion electron Mössbauer spectroscopy measurements of the paramagnetic state. The role of the dipole–dipole interactions and their interplay with the out-of-plain magnetic anisotropy in the variation of the blocking temperature has been investigated by Monte-Carlo simulations. - Highlights: • Multilayers of [0.4 nm Fe/5 nm Ag]{sub n} (n=1,2,5,10, and 20) were grown over Si. • Large increase of the superparamagnetic blocking temperature up to n=10 is observed. • The average Fe grain size does not change in the subsequent layers. • Perpendicular anisotropy enhances the dipolar coupling and the blocking temperature.

  7. Novel magnetic controlled plasma sputtering method

    International Nuclear Information System (INIS)

    Axelevich, A.; Rabinovich, E.; Golan, G.

    1996-01-01

    A novel method to improve thin film vacuum sputtering is presented. This method is capable of controlling the sputtering plasma via an external set of magnets, in a similar fashion to the tetrode sputtering method. The main advantage of the Magnetic Controlled Plasma Sputtering (MCPS) is its ability to independently control all deposition parameters without any interference or cross-talk. Deposition rate, using the MCPS, is found to be almost twice the rate of triode and tetrode sputtering techniques. Experimental results using the MCPS to deposit Ni layers are described. It was demonstrated that using the MCPS method the ion beam intensity at the target is a result of the interaction of a homogeneous external magnetic field and the controlling magnetic fields. The MCPS method was therefore found to be beneficial for the production of pure stoichiometric thin solid films with high reproducibility. This method could be used for the production of compound thin films as well. (authors)

  8. Achievement of normally-off AlGaN/GaN high-electron mobility transistor with p-NiO{sub x} capping layer by sputtering and post-annealing

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shyh-Jer [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, Taiwan (China); Chou, Cheng-Wei, E-mail: j2222222229@gmail.com [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, Taiwan (China); Su, Yan-Kuin, E-mail: yksu@mail.ncku.edu.tw [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, Taiwan (China); Lin, Jyun-Hao; Yu, Hsin-Chieh; Chen, De-Long [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, Taiwan (China); Ruan, Jian-Long [National Chung-Shan Institute of Science and Technology, Taoyuan, Taiwan (China)

    2017-04-15

    Highlights: • A technique to fabricate normally off GaN-based high-electron mobility transistor (HEMT) by sputtering and post-annealing p-NiO{sub x} capping layer. • The V{sub th} shifts from −3 V in the conventional transistor to 0.33 V, and on/off current ratio became 10{sup 7}. • The reverse gate leakage current is 10{sup −9} A/mm, and the off-state drain-leakage current is 10{sup −8} A/mm. • The V{sub th} hysteresis is extremely small at about 33 mV. - Abstract: In this paper, we present a technique to fabricate normally off GaN-based high-electron mobility transistor (HEMT) by sputtering and post-annealing p-NiO{sub x} capping layer. The p-NiO{sub x} layer is produced by sputtering at room temperature and post-annealing at 500 °C for 30 min in pure O{sub 2} environment to achieve high hole concentration. The V{sub th} shifts from −3 V in the conventional transistor to 0.33 V, and on/off current ratio became 10{sup 7}. The forward and reverse gate breakdown increase from 3.5 V and −78 V to 10 V and −198 V, respectively. The reverse gate leakage current is 10{sup −9} A/mm, and the off-state drain-leakage current is 10{sup −8} A/mm. The V{sub th} hysteresis is extremely small at about 33 mV. We also investigate the mechanism that increases hole concentration of p-NiO{sub x} after annealing in oxygen environment resulted from the change of Ni{sup 2+} to Ni{sup 3+} and the surge of (111)-orientation.

  9. Role of the electron blocking layer in the graded-index separate confinement heterostructure nitride laser diodes

    Science.gov (United States)

    Bojarska, Agata; Goss, Jakub; Stanczyk, Szymon; Makarowa, Irina; Schiavon, Dario; Czernecki, Robert; Suski, Tadeusz; Perlin, Piotr

    2018-04-01

    In this work, we investigate the role of the electron blocking layer (EBL) in laser diodes based on a graded index separate confinement heterostructure. We compare two sets of devices with very different EBL aluminum composition (3% and 12%) and design (graded and superlattice). The results of electro-optical characterization of these laser diodes reveal surprisingly modest role of electron blocking layer composition in determination of the threshold current and the differential efficiency values. However, EBL structure influences the operating voltage, which is decreased for devices with lower EBL and superlattice EBL. We observe also the differences in the thermal stability of devices - characteristic temperature is lower for lasers with 3% Al in EBL.

  10. HOLE-BLOCKING LAYERS FOR SILICON/ORGANIC HETEROJUNCTIONS: A NEW CLASS OF HIGH-EFFICIENCY LOW-COST PV

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, James [Princeton Univ., NJ (United States)

    2017-12-04

    This project is the first investigation of the use of thin titanium dioxide layers on silicon as a hole-blocking / electron-transparent selective contact to silicon. The work was motivated by the goal of a high-efficiency low-cost silicon-based solar cells that could be processed entirely at low temperature (300 Degree Celsius) or less, without requiring plasma-processing.

  11. Enhancing Color Purity and Stable Efficiency of White Organic Light Diodes by Using Hole-Blocking Layer

    Directory of Open Access Journals (Sweden)

    Chien-Jung Huang

    2014-01-01

    Full Text Available The organic light-emitting diodes with triple hole-blocking layer (THBL formation sandwich structure which generate white emission were fabricated. The 5,6,11,12-tetraphenylnapthacene (Rubrene, (4,4′-N,N′-dicarbazolebiphenyl (CBP, and 4,4′-bis(2,2′diphenylvinil-1,1′-biphenyl (DPVBi were used as emitting materials in the device. The function of CBP layer is not only an emitting layer but also a hole-blocking layer (HBL, and the Rubrene was doped into the CBP. The optimal configuration structure was indium tin oxide (ITO/Molybdenum trioxide (MoO3 (5 nm/[4,4-bis[N-(1-naphthyl-N-phenylamino]biphenyl (NPB (35 nm/CBP (HBL1 (5 nm/DPVBi (I (10 nm/CBP (HBL2 : Rubrene (4 : 1 (3 nm/DPVBi (II (30 nm/CBP (HBL3 (2 nm/4,7-diphenyl-1,10-phenanthroline (BPhen (10 nm/Lithium fluoride (LiF/aluminum (Al. The result showed that the device with Rubrene doped in CBP (HBL2 exhibited a stable white emission with the color coordinates of (0.322, 0.368, and the coordinate with the slight shift of ±Δx,y = (0.001, 0.011 for applied voltage of 8–12 V was observed.

  12. Development of dual-layer GSO depth-of-interaction block detector using angled optical fiber

    Energy Technology Data Exchange (ETDEWEB)

    Okumura, Satoshi, E-mail: okumura.satoshi@c.mbox.nagoya-u.ac.jp [Nagoya University Graduate School of Medicine (Japan); Yamamoto, Seiichi [Nagoya University Graduate School of Medicine (Japan); Watabe, Hiroshi [Cyclotron and Radioisotope Center (CYRIC), Tohoku University (Japan); Kato, Natsuki; Hamamura, Huka [Nagoya University Graduate School of Medicine (Japan)

    2015-05-01

    A PET system for small animals requires a small detector ring to obtain high-spatial resolution images. However, when we use a relatively large size of photodetector such as a position-sensitive photomultiplier tube (PSPMT), the detector ring is arranged in a hexagonal- or octagonal-shape, and the PET system has large gaps between the block detectors. The large gaps produce image distortion, and the reconstruction algorithm is difficult. To solve these problems, we proposed to arrange two scintillator blocks on one PSPMT using two angled optical fiber-based image guides. We could set two scintillator blocks angled at 22.5° on a PSPMT so that these scintillator blocks are arranged in a nearly circular (hexadecagonal) shape with eight developed block detectors. We used Gd{sub 2}SiO{sub 5} (GSO) scintillators with Ce concentrations of 1.5 mol% (decay time: 39 ns) and 0.4 mol% (decay time: 63 ns). Sizes of these GSO cells were 1.6×2.4×7.0 mm{sup 3} and 1.6×2.4×8.0 mm{sup 3} for 1.5 mol% Ce and 0.4 mol% Ce, respectively. These two types of GSO were arranged in an 11×15 matrix and optically coupled in the depth direction to form a depth-of-interaction (DOI) detector. Two GSO blocks and two optical fiber-based image guides were optically coupled to a 2-in. PSPMT (Hamamatsu Photonics H8500: 8×8 anodes). We measured the performances of the block detector with Cs-137 gamma photons (662-keV). We could resolve almost all pixels clearly in a two-dimensional position histogram. The average peak-to-valley ratios (P/Vs) of the two-dimensional position histogram along profiles were 2.6 and 4.8 in horizontal and vertical directions, respectively. The energy resolution was 28.4% full-width at half-maximum (FWHM). The pulse shape spectra showed good separation with a P/V of 5.2. The developed block detector performed well and shows promise for the development of high-sensitivity and high-spatial resolution PET systems.

  13. Development of dual-layer GSO depth-of-interaction block detector using angled optical fiber

    Science.gov (United States)

    Okumura, Satoshi; Yamamoto, Seiichi; Watabe, Hiroshi; Kato, Natsuki; Hamamura, Huka

    2015-05-01

    A PET system for small animals requires a small detector ring to obtain high-spatial resolution images. However, when we use a relatively large size of photodetector such as a position-sensitive photomultiplier tube (PSPMT), the detector ring is arranged in a hexagonal- or octagonal-shape, and the PET system has large gaps between the block detectors. The large gaps produce image distortion, and the reconstruction algorithm is difficult. To solve these problems, we proposed to arrange two scintillator blocks on one PSPMT using two angled optical fiber-based image guides. We could set two scintillator blocks angled at 22.5° on a PSPMT so that these scintillator blocks are arranged in a nearly circular (hexadecagonal) shape with eight developed block detectors. We used Gd2SiO5 (GSO) scintillators with Ce concentrations of 1.5 mol% (decay time: 39 ns) and 0.4 mol% (decay time: 63 ns). Sizes of these GSO cells were 1.6×2.4×7.0 mm3 and 1.6×2.4×8.0 mm3 for 1.5 mol% Ce and 0.4 mol% Ce, respectively. These two types of GSO were arranged in an 11×15 matrix and optically coupled in the depth direction to form a depth-of-interaction (DOI) detector. Two GSO blocks and two optical fiber-based image guides were optically coupled to a 2-in. PSPMT (Hamamatsu Photonics H8500: 8×8 anodes). We measured the performances of the block detector with Cs-137 gamma photons (662-keV). We could resolve almost all pixels clearly in a two-dimensional position histogram. The average peak-to-valley ratios (P/Vs) of the two-dimensional position histogram along profiles were 2.6 and 4.8 in horizontal and vertical directions, respectively. The energy resolution was 28.4% full-width at half-maximum (FWHM). The pulse shape spectra showed good separation with a P/V of 5.2. The developed block detector performed well and shows promise for the development of high-sensitivity and high-spatial resolution PET systems.

  14. Large Stokes shift downshifting Eu(III) films as efficiency enhancing UV blocking layers for dye sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, M.; Ahmed, H.; Doran, J.; Norton, B. [Dublin Energy Laboratory, Dublin Institute of Technology (Ireland); Bosch-Jimenez, P.; Della Pirriera, M.; Torralba-Calleja, E.; Gutierrez Tauste, D.; Aubouy, L. [Leitat Technological Center, Terrassa (Spain); Daren, S.; Solomon-Tsvetkov, F. [Daren Laboratories, Ness-Ziona (Israel); Galindo, S.; Voz, C.; Puigdollers, J. [Universitat Politecnica Catalunya, Barcelona (Spain)

    2015-01-01

    Large Stokes shift downshifting organolanthanide complex, Eu(tta){sub 3}phen, is examined for inclusion in polymeric layers to replace the UV blocking layer in dye sensitized solar cell (DSSC) technology. The UV blocking layer increases stability but power conversion efficiency decreases as incident UV photons are not converted into photocurrent. Eu(tta){sub 3}phen doped polymeric film are prepared and attached to DSSC devices following optimized thickness and concentration from a ray-trace numerical model for the specific DSSC. External quantum efficiency is significantly increased in the UV spectral region compared to DSSCs utilizing a passive, non-luminescent, UV-BL. High Eu(tta){sub 3}phen film transparency in the visible range minimizes DSSC EQE losses at visible wavelengths. Short-circuit current (I{sub sc}) enhancement due to downshifting is demonstrated (∝1%) in small-scale DSSC prototypes, where the specific geometry limits the photon collection efficiency and overall enhancement. Model predictions indicate that 2%-3% Isc enhancement is realizable in flexible single DSSC compared to, non-luminescent, UV-BL. Added to this, in outdoor conditions taking into account diffuse light, the increment in I{sub sc} can increase 50% more. Although photostability of the blended LSS-DS polymer films is not sufficient to be useful for medium-long term outdoor PV applications, the results demonstrate that significant efficiency enhancement can be realized. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Modeling and simulation of experimentally fabricated QDSSC using ZnS as light absorbing and blocking layer

    Science.gov (United States)

    Mehrabian, Masood; Dalir, Sina

    2017-07-01

    Abstract—Two main factors which limit the power conversion efficiency of solar cells are light absorption and recombination processes. In photovoltaic (PV) devices, low energy photons cannot be absorbed and excite electrons from valance band to conduction band, hence do not contribute to the current. On the other hand, high energy photons cannot be efficiently used due to a poor match to the energy gap. Existence of charge recombination in PV devices causes the low conversion performance, which is indicated by the low open-circuit voltage ( V OC ). Using a blocking layer in system could effectively reduce the recombination of charge carriers. In this study, we simulated a solar cell with ITO/ZnO/P3HT&PCBM/Ag structure. To prevent the charge recombination, a ZnS QD layer was used which acts as a light absorbing and a recombination blocking layer in the ITO/ZnO film/ZnS QD/P3HT&PCBM/Ag structure. The simulated J- V characteristics of solar cells showed a close match with the experimental results. Simulate data showed an increase of conversion efficiency in ZnS QDSSC from 1.71 to 3.10%, which is relatively 81.28% increase.

  16. Improving the photovoltaic parameters in Quantum dot sensitized solar cells through employment of chemically deposited compact titania blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Rajendra Prasad, M.B., E-mail: rajendraprasadmb75@gmail.com [Advanced Physics Laboratory, Department of Physics, SavitibaiPhule Pune University, Pune, 411007 (India); National Defence Academy, Khadakwasla, Pune, 411023 (India); Kadam, Vishal [Advanced Physics Laboratory, Department of Physics, SavitibaiPhule Pune University, Pune, 411007 (India); Joo, Oh-Shim [Korea Institute of Science and Technology, PO Box No. 131, Chongryang, Seoul, 130-650 (Korea, Republic of); Pathan, Habib M. [Advanced Physics Laboratory, Department of Physics, SavitibaiPhule Pune University, Pune, 411007 (India)

    2017-06-15

    Incorporation of compact blocking layer at the Transparent Conducting Oxide (TCO)/Electrolyte interface is an effective method to improve the device performance in QDSSC through mitigation of electron recombinations at this interface. This paper reports the most facile and cost effective method of depositing a rutile titania Compact Layer (CL) over Fluorine doped Tin Oxide (FTO) substrate and its application in titania based CdS QD sensitized solar cells. The deposited compact layers are characterized to study their structural, optical, morphological and electrochemical properties using X-Ray Diffractometry, UV–Visible spectroscopy, Scanning electron microscopy, Cyclic Voltammetry and Contact Angle measurements. Sandwich solar cells are fabricated using these CL based electrodes and characterized using Electrochemical Impedance Spectroscopy, Open Circuit Voltage Decay and J-V characteristics. The CL incorporated CdS QDSSC showed more than 100% increase in the photoconversion efficiency (1.68%) as compared to its bare FTO counterpart (0.73%) proving the efficacy of employed strategy. - Highlights: • Deposited titania compact layer by a facile room temperature chemical bath method. • Employed this to mitigate back electron transfer at TCO/Electrolyte interface. • Compact layer incorporation has improved the solar cell performance by 130%.

  17. Increased luminance of MEH-PPV and PFO based PLEDs by using salmon DNA as an electron blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Madhwal, Devinder, E-mail: devindermadhwal@gmail.co [Material Science Laboratory, Department of Electronic Science, University of Delhi South campus, Benito Juarez Road, New Delhi-110021 (India); Rait, S.S.; Verma, A.; Kumar, Amit; Bhatnagar, P.K.; Mathur, P.C. [Material Science Laboratory, Department of Electronic Science, University of Delhi South campus, Benito Juarez Road, New Delhi-110021 (India); Onoda, M. [Department of Electrical Engineering and Computer Science, University of Hyogo, Himeji (Japan)

    2010-02-15

    The effect of salmon DNA-CTMA as an electron blocking layer (EBL) has been examined on the performance of MEH-PPV and PFO-based light emitting diodes. Though the turn-on voltage increases with incorporation of EBL, a significant increase in luminance and luminous efficiency for both the devices is observed. The EBL improves the device performance by blocking electrons at the EBL-polymer interface, thereby increasing the recombination probability of electrons and holes. The luminance of the MEH-PPV based Bio-LED increases to 100 cd/m{sup 2} from 30 cd/m{sup 2} while a corresponding increase for the PFO based LED is to 160 cd/m{sup 2} from 80 cd/m{sup 2} with and without EBL, respectively.

  18. Very thin thermally stable TiO2 blocking layers with enhanced electron transfer for solar cells

    Czech Academy of Sciences Publication Activity Database

    Kment, Š.; Krýsová, Hana; Hubička, Zdeněk; Kmentová, H.; Kavan, Ladislav; Zbořil, R.

    2017-01-01

    Roč. 9, DEC 2017 (2017), s. 122-129 ISSN 2352-9407 R&D Projects: GA MŠk(CZ) LM2015073; GA ČR GA13-07724S Grant - others:GA MŠk(CZ) LO1305 Institutional support: RVO:61388955 ; RVO:68378271 Keywords : Cyclic voltammetry * Impedance spectroscopy * Photochemistry * Solar cell * TiO blocking layer 2 Subject RIV: CG - Electrochemistry; BM - Solid Matter Physics ; Magnetism (FZU-D) OBOR OECD: Electrochemistry (dry cell s, batteries, fuel cell s, corrosion metals, electrolysis); Condensed matter physics (including formerly solid state physics, supercond.) (FZU-D)

  19. Very thin thermally stable TiO2 blocking layers with enhanced electron transfer for solar cells

    Czech Academy of Sciences Publication Activity Database

    Kment, Š.; Krýsová, Hana; Hubička, Zdeněk; Kmentová, H.; Kavan, Ladislav; Zbořil, R.

    2017-01-01

    Roč. 9, DEC 2017 (2017), s. 122-129 ISSN 2352-9407 R&D Projects: GA MŠk(CZ) LM2015073; GA ČR GA13-07724S Grant - others:GA MŠk(CZ) LO1305 Institutional support: RVO:61388955 ; RVO:68378271 Keywords : Cyclic voltammetry * Impedance spectroscopy * Photochemistry * Solar cell * TiO blocking layer 2 Subject RIV: CG - Electrochemistry; BM - Solid Matter Physics ; Magnetism (FZU-D) OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis); Condensed matter physics (including formerly solid state physics, supercond.) (FZU-D)

  20. Artificial twin-layer configurations of Zn(O,S) films by radio frequency sputtering in all dry processed eco-friendly Cu(In,Ga)Se2 solar cells

    Science.gov (United States)

    Liu, Wei; Fan, Yu; Li, Xiaodong; Lin, Shuping; Liu, Yang; Shi, Sihan; Wang, He; Zhou, Zhiqiang; Zhang, Yi; Sun, Yun

    2018-03-01

    Cu(In,Ga)Se2 thin film solar cells are of great interest for research and industrial applications with their high conversion efficiencies, long-term stability and significant lifetimes. Such a solar cell of a p-n junction consists of p-type Cu(In,Ga)Se2 films as a light absorber and n-type CdS as a buffer layer, which often emerges with intrinsic ZnO. Aimed at eco-friendly fabrication protocols, a large number of strategies have been investigated to fabricate a Cd-free n-type buffer layer such as Zn(O,S) in Cu(In,Ga)Se2 solar cells. Also, if the Zn(O,S) films are prepared by coevaporation or sputtering, it will offer high compatibility with the preferred mass production. Here, we propose and optimize a dry method for Zn(O,S) deposition in a radio frequency sputtering. In particular, the strategy for the twin-layer configurations of Zn(O,S) films not only greatly improve their electrical conductance and suppress charge carrier recombination, but also avoid degradation of the Zn(O,S)/Cu(In,Ga)Se2 interfaces. Indeed, the high quality of such twin Zn(O,S) layers have been reflected in the similar conversion efficiencies of the complete solar cells as well as the large short-circuit current density, which exceeds the CdS reference device. In addition, Zn(O,S) twin layers have reduced the production time and materials by replacing the CdS/i-ZnO layers, which removes two fabrication steps in the multilayered thin film solar cells. Furthermore, the device physics for such improvements have been fully unveiled with both experimental current–voltage and capacitance–voltage spectroscopies and device simulations via wxAMPS program. Finally, the proposed twin-layer Zn(O,S)/Cu(In,Ga)Se2 interfaces account for the broadening of the depletion region of photogenerated charge carriers, which greatly suppress the carrier recombination at the space charge region, and eventually lead to the more efficient collection of charge carriers at both electrodes.

  1. Cement stabilized red earth as building block and structural pavement layer

    Directory of Open Access Journals (Sweden)

    G.V. RAMA SUBBARAO

    2014-12-01

    Full Text Available Red Earth is most commonly used as material in the building and road construction. Many a times, the red earth found in various quarries is found not suitable for construction. Cement of 4 and 8% of dry mass of red earth was added to improve its suitability as building block and structural pavement material. To know the influence of waste plastic fiber on cement stabilized red earth, 1% fiber was also added to the mixture. It is shown that the compressive strength of cement stabilized red earth blocks was improved with seven days of curing. The addition of cement to red earth enhanced soaked CBR value. The soaked CBR value of fiber reinforced cement stabilized red earth was about 1.3 to 1.5 times that of unreinforced cement stabilized red earth.

  2. Tailoring of polarization in electron blocking layer for electron confinement and hole injection in ultraviolet light-emitting diodes

    International Nuclear Information System (INIS)

    Lu, Yu-Hsuan; Pilkuhn, Manfred H.; Fu, Yi-Keng; Chu, Mu-Tao; Huang, Shyh-Jer; Su, Yan-Kuin; Wang, Kang L.

    2014-01-01

    The influence of the AlGaN electron blocking layer (EBL) with graded aluminum composition on electron confinement and hole injection in AlGaN-based ultraviolet light-emitting diodes (LEDs) are investigated. The light output power of LED with graded AlGaN EBL was markedly improved, comparing to LED with conventional EBL. In experimental results, a high increment of 86.7% can be obtained in light output power. Simulation analysis shows that via proper modification of the barrier profile from the last barrier of the active region to EBL, not only the elimination of electron overflow to p-type layer can be achieved but also the hole injection into the active region can be enhanced, compared to a conventional LED structure. The dominant factor to the performance improvement is shown to be the modulation of polarization field by the graded Al composition in EBL

  3. Tailoring of polarization in electron blocking layer for electron confinement and hole injection in ultraviolet light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yu-Hsuan; Pilkuhn, Manfred H. [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Fu, Yi-Keng; Chu, Mu-Tao [Electronics and Optoelectronics Research Laboratories, Industrial Technology Research Institute, Hsinchu 31040, Taiwan (China); Huang, Shyh-Jer, E-mail: yksu@mail.ncku.edu.tw, E-mail: totaljer48@gmail.com [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Electrical Engineering, University of California at Los Angeles, Los Angeles, California 90095 (United States); Su, Yan-Kuin, E-mail: yksu@mail.ncku.edu.tw, E-mail: totaljer48@gmail.com [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Electronic Engineering, Kun-Shan University, Tainan 71003, Taiwan (China); Wang, Kang L. [Department of Electrical Engineering, University of California at Los Angeles, Los Angeles, California 90095 (United States)

    2014-03-21

    The influence of the AlGaN electron blocking layer (EBL) with graded aluminum composition on electron confinement and hole injection in AlGaN-based ultraviolet light-emitting diodes (LEDs) are investigated. The light output power of LED with graded AlGaN EBL was markedly improved, comparing to LED with conventional EBL. In experimental results, a high increment of 86.7% can be obtained in light output power. Simulation analysis shows that via proper modification of the barrier profile from the last barrier of the active region to EBL, not only the elimination of electron overflow to p-type layer can be achieved but also the hole injection into the active region can be enhanced, compared to a conventional LED structure. The dominant factor to the performance improvement is shown to be the modulation of polarization field by the graded Al composition in EBL.

  4. Solar system sputtering

    Science.gov (United States)

    Tombrello, T. A.

    1982-01-01

    The sites and materials involved in solar system sputtering of planetary surfaces are reviewed, together with existing models for the processes of sputtering. Attention is given to the interaction of the solar wind with planetary atmospheres in terms of the role played by the solar wind in affecting the He-4 budget in the Venus atmosphere, and the erosion and differentiation of the Mars atmosphere by solar wind sputtering. The study is extended to the production of isotopic fractionation and anomalies in interplanetary grains by irradiation, and to erosion effects on planetary satellites with frozen volatile surfaces, such as with Io, Europa, and Ganymede. Further measurements are recommended of the molecular form of the ejected material, the yields and energy spectra of the sputtered products, the iosotopic fractionation sputtering causes, and the possibility of electronic sputtering enhancement with materials such as silicates.

  5. Improvement of a block co-polymer (PS-b-PDMS) template etch profile using amorphous carbon layer

    Science.gov (United States)

    Oh, JiSoo; Oh, Jong Sik; Sung, DaIn; Yim, SoonMin; Song, SeungWon; Yeom, GeunYoung

    2017-03-01

    Block copolymers (BCPs) are consisted of at least two types of monomers which have covalent bonding. One of the widely investigated BCPs is polystyrene-block-polydimethylsiloxane (PS-b-PDMS), which is used as an alternative patterning method for various deep nanoscale devices due to its high Flory-Huggins interaction parameter (χ), such as optical devices and transistors, replacing conventional photolithography. As an alternate or supplementary nextgeneration lithography technology to extreme ultraviolet lithography (EUVL), BCP lithography utilizing the DSA of BCP has been actively studied. However, the nanoscale BCP mask material is easily damaged by the plasma and has a very low etch selectivity over bottom semiconductor materials, because it is composed of polymeric materials even though it contains Si in PDMS. In this study, an amorphous carbon layer (ACL) was inserted as a hardmask material between BCP and materials to be patterned, and, by using O2 plasmas, the characteristics of dry etching of ACL for high aspect ratio (HAR) using a 10 nm PDMS pattern were investigated. The results showed that, by using a PS-b-PDMS pattern with an aspect ratio of 0.3 0.9:1, a HAR PDMS/ACL double layer mask with an aspect ratio of 10:1 could be fabricated. In addition, by the optimization of the plasma etch process, ACL masks with excellent sidewall roughness (SWR,1.35 nm) and sidewall angle (SWA, 87.9˚) could be fabricated.

  6. Reactive sputter deposition

    CERN Document Server

    Mahieu, Stijn

    2008-01-01

    In this valuable work, all aspects of the reactive magnetron sputtering process, from the discharge up to the resulting thin film growth, are described in detail, allowing the reader to understand the complete process. Hence, this book gives necessary information for those who want to start with reactive magnetron sputtering, understand and investigate the technique, control their sputtering process and tune their existing process, obtaining the desired thin films.

  7. Estimates of Sputter Yields of Solar-Wind Heavy Ions of Lunar Regolith Materials

    Science.gov (United States)

    Barghouty, Abdulmasser F.; Adams, James H., Jr.

    2008-01-01

    At energies of approximately 1 keV/amu, solar-wind protons and heavy ions interact with the lunar surface materials via a number of microscopic interactions that include sputtering. Solar-wind induced sputtering is a main mechanism by which the composition of the topmost layers of the lunar surface can change, dynamically and preferentially. This work concentrates on sputtering induced by solar-wind heavy ions. Sputtering associated with slow (speeds the electrons speed in its first Bohr orbit) and highly charged ions are known to include both kinetic and potential sputtering. Potential sputtering enjoys some unique characteristics that makes it of special interest to lunar science and exploration. Unlike the yield from kinetic sputtering where simulation and approximation schemes exist, the yield from potential sputtering is not as easy to estimate. This work will present a preliminary numerical scheme designed to estimate potential sputtering yields from reactions relevant to this aspect of solar-wind lunar-surface coupling.

  8. Nickel hydroxide ultrathin nanosheets as building blocks for electrochemically active layers

    Czech Academy of Sciences Publication Activity Database

    Schneiderová, Barbora; Demel, Jan; Pleštil, Josef; Janda, Pavel; Bohuslav, Jan; Ihiawakrim, D.; Ersen, O.; Rogez, G.; Lang, Kamil

    2013-01-01

    Roč. 1, č. 37 (2013), s. 11429-11437 ISSN 2050-7488 R&D Projects: GA ČR GAP207/10/1447; GA ČR GP13-09462P Institutional support: RVO:61388980 ; RVO:61389013 ; RVO:61388955 Keywords : layered hydroxide * delamination * nanosheet * batteries Subject RIV: CA - Inorganic Chemistry; CD - Macromolecular Chemistry (UMCH-V); CF - Physical ; Theoretical Chemistry (UFCH-W)

  9. A tribo-mechanical analysis of PVA-based building-blocks for implementation in a 2-layered skin model.

    Science.gov (United States)

    Morales Hurtado, M; de Vries, E G; Zeng, X; van der Heide, E

    2016-09-01

    Poly(vinyl) alcohol hydrogel (PVA) is a well-known polymer widely used in the medical field due to its biocompatibility properties and easy manufacturing. In this work, the tribo-mechanical properties of PVA-based blocks are studied to evaluate their suitability as a part of a structure simulating the length scale dependence of human skin. Thus, blocks of pure PVA and PVA mixed with Cellulose (PVA-Cel) were synthesised via freezing/thawing cycles and their mechanical properties were determined by Dynamic Mechanical Analysis (DMA) and creep tests. The dynamic tests addressed to elastic moduli between 38 and 50kPa for the PVA and PVA-Cel, respectively. The fitting of the creep compliance tests in the SLS model confirmed the viscoelastic behaviour of the samples with retardation times of 23 and 16 seconds for the PVA and PVA-Cel, respectively. Micro indentation tests were also achieved and the results indicated elastic moduli in the same range of the dynamic tests. Specifically, values between 45-55 and 56-81kPa were obtained for the PVA and PVA-Cel samples, respectively. The tribological results indicated values of 0.55 at low forces for the PVA decreasing to 0.13 at higher forces. The PVA-Cel blocks showed lower friction even at low forces with values between 0.2 and 0.07. The implementation of these building blocks in the design of a 2-layered skin model (2LSM) is also presented in this work. The 2LSM was stamped with four different textures and their surface properties were evaluated. The hydration of the 2LSM was also evaluated with a corneometer and the results indicated a gradient of hydration comparable to the human skin. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Metal-oxide-semiconductor AlGaN/GaN heterostructure field-effect transistors using TiN/AlO stack gate layer deposited by reactive sputtering

    International Nuclear Information System (INIS)

    Li, Liuan; Wang, Qingpeng; Nakamura, Ryosuke; Jiang, Ying; Ao, Jin-Ping; Xu, Yonggang

    2015-01-01

    In this paper, the influence of deposition conditions and post annealing upon the device performance of sputtering-deposited TiN/AlO/AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors is reported. The metal-oxide-semiconductor structure on GaN with AlO deposited in a medium O 2 /Ar ratio possessed the smallest interfacial state density and reverse leakage current. Metal-oxide-semiconductor heterostructure field-effect transistors with a small hysteresis and a low leakage current were obtained by depositing AlO with a medium O 2 /Ar ratio and post-annealing at 600 °C for 1 min. After annealing, the maximum transconductance shows some decrease, resulting in a decrease of saturation drain current. (paper)

  11. Layer-by-Layer Formation of Block-Copolymer-Derived TiO2 for Solid-State Dye-Sensitized Solar Cells

    KAUST Repository

    Guldin, Stefan

    2011-12-15

    Morphology control on the 10 nm length scale in mesoporous TiO 2 films is crucial for the manufacture of high-performance dye-sensitized solar cells. While the combination of block-copolymer self-assembly with sol-gel chemistry yields good results for very thin films, the shrinkage during the film manufacture typically prevents the build-up of sufficiently thick layers to enable optimum solar cell operation. Here, a study on the temporal evolution of block-copolymer-directed mesoporous TiO 2 films during annealing and calcination is presented. The in-situ investigation of the shrinkage process enables the establishment of a simple and fast protocol for the fabrication of thicker films. When used as photoanodes in solid-state dye-sensitized solar cells, the mesoporous networks exhibit significantly enhanced transport and collection rates compared to the state-of-the-art nanoparticle-based devices. As a consequence of the increased film thickness, power conversion efficiencies above 4% are reached. Fabrication of sufficiently thick mesoporous TiO 2 photoelectrodes with morphology control on the 10 nm length scale is essential for solid-state dye-sensitized solar cells (ss-DSC). This study of the temporal evolution of block-copolymer-directed mesoporous TiO 2 films during annealing and calcination enables the build-up of sufficiently thick films for high-performance ssDSC devices. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Concurrent formation of blocking-oxide and charge-trap layers by selective oxidation and phase separation of a SiGeO layer

    International Nuclear Information System (INIS)

    Han, Dongwoo; Jang, Seunghun; Kim, Hyunseung; Han, Moonsup

    2011-01-01

    Ge nanocrystals have recently been studied to improve next-generation nonvolatile memories (NVMs) by substituting Si or ZnO nanocrystals because of their higher dielectric constants, smaller band gap energies, and stronger size effects in the nanometer range. We propose a new method to fabricate a metal-electrode/oxide/insulator/oxide/semiconductor (MOIOS) structure. We deposited a SiGeO compound on an early-made-tunnel-oxide surface and attempted an appropriate post-thermal oxidation to produce simultaneously a blocking-oxide layer (BOL) and a charge-trap layer (CTL). We point out the crucial points for good memory behavior in the MOIOS structure investigated in this work. Based on the high-quality Ge nanocrystals observed in the CTL with a high-resolution transmission microscope (HRTEM) and the prominent behavior of the memory window opening in the capacitance-voltage (C-V) characteristics, we propose a fabrication process that fulfills those crucial points. Furthermore, the process forms concurrently both a high-quality BOL and a high-quality CTL easily in a single step. We expect the method to lead to cost savings and to improve product efficiency in the fabrication of next-generation NVM structures.

  13. Sputtering of water ice

    DEFF Research Database (Denmark)

    Baragiola, R.A.; Vidal, R.A.; Svendsen, W.

    2003-01-01

    We present results of a range of experiments of sputtering of water ice together with a guide to the literature. We studied how sputtering depends on the projectile energy and fluence, ice growth temperature, irradiation temperature and external electric fields. We observed luminescence from...

  14. Contributions of solar-wind induced potential sputtering to the lunar surface erosion rate and it's exosphere

    Science.gov (United States)

    Alnussirat, S. T.; Barghouty, A. F.; Edmunson, J. E.; Sabra, M. S.; Rickman, D. L.

    2018-04-01

    Sputtering of lunar regolith by solar-wind protons and heavy ions with kinetic energies of about 1 keV/amu is an important erosive process that affects the lunar surface and exosphere. It plays an important role in changing the chemical composition and thickness of the surface layer, and in introducing material into the exosphere. Kinetic sputtering is well modeled and understood, but understanding of mechanisms of potential sputtering has lagged behind. In this study we differentiate the contributions of potential sputtering from the standard (kinetic) sputtering in changing the chemical composition and erosion rate of the lunar surface. Also we study the contribution of potential sputtering in developing the lunar exosphere. Our results show that potential sputtering enhances the total characteristic sputtering erosion rate by about 44%, and reduces sputtering time scales by the same amount. Potential sputtering also introduces more material into the lunar exosphere.

  15. 4P-NPD ultra thin-films as efficient exciton blocking layers in DBP/C70 based organic solar cells

    DEFF Research Database (Denmark)

    Patil, Bhushan Ramesh; Liu, Yiming; Qamar, Talha

    2017-01-01

    Exciton blocking effects from ultra thin layers of N,N'-di-1-naphthalenyl-N,N'-diphenyl [1,1':4',1'':4'',1'''-quaterphenyl]-4,4'''-diamine (4P-NPD) was investigated in small molecule based inverted Organic Solar Cells (OSCs) using Tetraphenyldibenzoperiflanthene (DBP) as the electron donor material...... and fullerene (C70) as the electron acceptor material. The short-circuit current density (Jsc) and PCE of the optimized OSCs with 0.7 nm thick 4P-NPD were approx. 16 % and 24 % higher, respectively, compared to reference devices without exciton blocking layers. Drift diffusion based device modeling...... was conducted to model the full Current density – Voltage (JV) characteristics and EQE spectrum of the OSCs, and photoluminescence measurements was conducted to investigate the exciton blocking effects with increasing thicknesses of the 4P-NPD layer. Importantly, coupled optical and electrical modeling studies...

  16. In-situ synthesis of TiO2rutile/anatase heterostructure by DC magnetron sputtering at room temperature and thickness effect of outermost rutile layer on photocatalysis.

    Science.gov (United States)

    Hui, Wang; Guodong, Shi; Xiaoshu, Zhang; Wei, Zhang; Lin, Huang; Ying, Yu

    2017-10-01

    TiO 2 rutile/anatase heterostructure thin films with varying rutile thickness have been in-situ synthesized via DC magnetron sputtering with Ar gas at room temperature. The crystal texture, surface morphology, energy gap and optical properties of the films have been investigated by X-ray diffraction meter, grazing incidence X-ray diffraction meter, Raman spectroscopy, scanning electron microscopy, and UV-visible spectrophotometer, which indicates that the rutile/anatase heterostructure films are successfully fabricated. The further degradation experiments display that the photocatalytic activity can be dramatically affected by the thickness of the outmost rutile layer and the 100nm thickness exhibits the best performance in all of the TiO 2 thin films. With the increase of the outmost rutile layer, the optical band gap of TiO 2 film displays a systematic decrease slightly. However, the change in photocatalytic activity does not coincide with that in the band gap. The photoresponse and electrochemical properties of the thin films have been characterized to understand the mechanism of the varied photocatalytic activity. Copyright © 2017. Published by Elsevier B.V.

  17. 4P-NPD ultra-thin films as efficient exciton blocking layers in DBP/C70 based organic solar cells

    Science.gov (United States)

    Patil, Bhushan R.; Liu, Yiming; Qamar, Talha; Rubahn, Horst-Günter; Madsen, Morten

    2017-09-01

    Exciton blocking effects from ultra-thin layers of N,N‧-di-1-naphthalenyl-N,N‧-diphenyl [1,1‧:4‧,1″:4″,1‴-quaterphenyl]-4,4‴-diamine (4P-NPD) were investigated in small molecule-based inverted organic solar cells (OSCs) using tetraphenyldibenzoperiflanthene as the electron donor material and fullerene (C70) as the electron acceptor material. The short-circuit current density (J SC) and power conversion efficiency (PCE) of the optimized OSCs with 0.7 nm thick 4P-NPD were approximately 16% and 24% higher, respectively, compared to reference devices without exciton blocking layers (EBLs). Drift diffusion-based device modeling was conducted to model the full current density-voltage (JV) characteristics and external quantum efficiency spectrum of the OSCs, and photoluminescence measurements were conducted to investigate the exciton blocking effects with increasing thicknesses of the 4P-NPD layer. Importantly, coupled optical and electrical modeling studies of the device behaviors and exciton generation rates and densities in the active layer for different 4P-NPD layer thicknesses were conducted, in order to gain a complete understanding of the observed increase in PCE for 4P-NPD layer thicknesses up to 1 nm, and the observed decrease in PCE for layer thicknesses beyond 1 nm. This work demonstrates a route for guiding the integration of EBLs in OSC devices.

  18. Mechanism of hole injection enhancement in light-emitting diodes by inserting multiple hole-reservoir layers in electron blocking layer

    International Nuclear Information System (INIS)

    Zhao, Yukun; Wang, Shuai; Feng, Lungang; Li, Yufeng; Ding, Wen; Yun, Feng; Su, Xilin; Guo, Maofeng; Zhang, Ye

    2016-01-01

    In this study, gallium nitride (GaN) based light-emitting diodes (LEDs) with single and multiple hole-reservoir layers (HRLs) inserted in the electron-blocking layer (EBL) have been investigated numerically and experimentally. According to simulation results, a better electron confinement and a higher hole injection level can be achieved by the multiple HRLs inserted in the EBL region. To further reveal the underlying mechanism of hole injection enhancement experimentally, the active regions were intentionally designed to emit photons with three different wavelengths of 440 nm, 460 nm, and 480 nm, respectively. Based on the experimental results of photoluminescence (PL) and time-resolved PL (TRPL) measurements conducted at 298 K, the remarkable enhancement (148%) of PL intensities and significant increase in the decay times of the quantum wells close to p-GaN can be obtained. Therefore, the mechanism is proposed that carriers are able to reserve in the EBL region with multiple HRLs for a much longer time. Meanwhile, carriers could diffuse into the active region by tunnelling and/or thermo-electronic effect and then recombine efficiently, leading to the better carrier reservoir effect and higher hole injection in LEDs. As a result, by inserting multiple HRLs in the EBL region instead of single HRL, the experimental external quantum efficiency is enhanced by 19.8%, while the serious droop ratio is markedly suppressed from 37.0% to 27.6% at the high current injection of 100 A/cm 2 .

  19. Mechanism of hole injection enhancement in light-emitting diodes by inserting multiple hole-reservoir layers in electron blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yukun; Wang, Shuai; Feng, Lungang; Li, Yufeng; Ding, Wen [Key Laboratory of Physical Electronics and Devices of Ministry of Education and Shaanxi Provincial Key Laboratory of Photonics and Information Technology, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Solid-State Lighting Engineering Research Center, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Yun, Feng, E-mail: fyun2010@mail.xjtu.edu.cn [Key Laboratory of Physical Electronics and Devices of Ministry of Education and Shaanxi Provincial Key Laboratory of Photonics and Information Technology, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Solid-State Lighting Engineering Research Center, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Shaanxi Supernova Lighting Technology Co. Ltd, Xi' an, Shaanxi 710075 (China); Su, Xilin [Shaanxi Supernova Lighting Technology Co. Ltd, Xi' an, Shaanxi 710075 (China); Guo, Maofeng [Solid-State Lighting Engineering Research Center, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Shaanxi Supernova Lighting Technology Co. Ltd, Xi' an, Shaanxi 710075 (China); Zhang, Ye [Solid-State Lighting Engineering Research Center, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)

    2016-03-14

    In this study, gallium nitride (GaN) based light-emitting diodes (LEDs) with single and multiple hole-reservoir layers (HRLs) inserted in the electron-blocking layer (EBL) have been investigated numerically and experimentally. According to simulation results, a better electron confinement and a higher hole injection level can be achieved by the multiple HRLs inserted in the EBL region. To further reveal the underlying mechanism of hole injection enhancement experimentally, the active regions were intentionally designed to emit photons with three different wavelengths of 440 nm, 460 nm, and 480 nm, respectively. Based on the experimental results of photoluminescence (PL) and time-resolved PL (TRPL) measurements conducted at 298 K, the remarkable enhancement (148%) of PL intensities and significant increase in the decay times of the quantum wells close to p-GaN can be obtained. Therefore, the mechanism is proposed that carriers are able to reserve in the EBL region with multiple HRLs for a much longer time. Meanwhile, carriers could diffuse into the active region by tunnelling and/or thermo-electronic effect and then recombine efficiently, leading to the better carrier reservoir effect and higher hole injection in LEDs. As a result, by inserting multiple HRLs in the EBL region instead of single HRL, the experimental external quantum efficiency is enhanced by 19.8%, while the serious droop ratio is markedly suppressed from 37.0% to 27.6% at the high current injection of 100 A/cm{sup 2}.

  20. Enhanced photocatalytic activity of hydrogenated and vanadium doped TiO2 nanotube arrays grown by anodization of sputtered Ti layers

    Science.gov (United States)

    Motola, Martin; Satrapinskyy, Leonid; Čaplovicová, Mária; Roch, Tomáš; Gregor, Maroš; Grančič, Branislav; Greguš, Ján; Čaplovič, Ľubomír; Plesch, Gustav

    2018-03-01

    TiO2 nanotube (TiNT) arrays were grown on silicon substrate via electrochemical anodization of titanium films sputtered by magnetron. To improve the photocatalytic activity of arrays annealed in air (o-TiNT), doping of o-TiNT with vanadium was performed (o-V/TiNT). These non-doped and doped TiNT arrays were also hydrogenated in H2/Ar atmosphere to r-TiNT and r-V/TiNT samples, respectively. Investigation of composition and morphology by X-ray diffraction (XRD), electron microscopy (SEM and TEM) and X-ray photoelectron spectroscopy (XPS) showed the presence of well-ordered arrays of anatase nanotubes with average diameter and length of 100 nm and 1.3 μm, respectively. In both oxidized and reduced V-doped samples, vanadium is partly dissolved in the structure of anatase and partly deposited in form of oxide on the nanotube surface. Vanadium-doped and reduced samples exhibited higher rates in the photodegradation of organic dyes (compared to non-modified o-TiNT sample) and this is caused by limitation of electron-hole recombination rates and by shift of the energy gap into visible region. The photocatalytic activity was measured under UV, sunlight and visible irradiation, and the corresponding efficiency increased in the order (o-TiNT) < (r-TiNT) < (o-V/TiNT) < (r-V/TiNT). Under visible light, only r-TiNT and r-V/TiNT showed significant photocatalytic activity.

  1. THE EFFECT OF PRESSURE, BIAS VOLTAGE AND ANNEALING TEMPERATURE ON N₂ AND N₂+SiH₄ DOPED WC/C DC MAGNETRON SPUTTERED LAYERS

    Directory of Open Access Journals (Sweden)

    Peter Hornak

    2017-12-01

    Full Text Available Tungsten carbide (WC/C layers are often researched due to their outstanding mechanical and tribological properties. Here, optimized indented hardness (HIT, indentation modulus (EIT and coefficient of friction (COF values were measured to study the effect of pressure and bias voltage on WC/C layers, deposited on Si by DC magnetron spluttering. Maximal values of HIT=37.2±4.8 GPa, EIT=447±28 GPa and COF=0.64±0.09 were obtained. Additionally, the effect of temperature on optimized layers deposited with and without N₂ and N₂+SiH₄ annealed at 200 °C, 500 °C and 800 °C, were also investigated. The values of HIT, EIT and COF and, observed morphology and structural composition of these contaminated and non-contaminated WC/C layers were evaluated. It was found that layer degradation occurred at different rates depending on the temperature and gas mixture used during the annealing and deposition process, respectively.

  2. Sputtering properties of tungsten 'fuzzy' surfaces

    International Nuclear Information System (INIS)

    Nishijima, D.; Baldwin, M.J.; Doerner, R.P.; Yu, J.H.

    2011-01-01

    Sputtering yields of He-induced W 'fuzzy' surfaces bombarded by Ar have been measured in the linear divertor plasma simulator PISCES-B. It is found that the sputtering yield of a fuzzy surface, Y fuzzy , decreases with increasing fuzzy layer thickness, L, and saturates at ∼10% of that of a smooth surface, Y smooth , at L > 1 μm. The reduction in the sputtering yield is suspected to be due mainly to the porous structure of fuzz, since the ratio, Y fuzzy /Y smooth follows (1 - p fuzz ), where p fuzz is the fuzz porosity. Further, Y fuzzy /Y smooth is observed to increase with incident ion energy, E i . This may be explained by an energy dependent change in the angular distribution of sputtered W atoms, since at lower E i , the angular distribution is observed to become more butterfly-shaped. That is, a larger fraction of sputtered W atoms can line-of-sight deposit/stick onto neighboring fuzz nanostructures for lower E i butterfly distributions, resulting in lower ratio of Y fuzzy /Y smooth .

  3. Enhancing carrier injection in the active region of a 280nm emission wavelength LED using graded hole and electron blocking layers

    KAUST Repository

    Janjua, Bilal

    2014-02-27

    A theoretical investigation of AlGaN UV-LED with band engineering of hole and electron blocking layers (HBL and EBL, respectively) was conducted with an aim to improve injection efficiency and reduce efficiency droop in the UV LEDs. The analysis is based on energy band diagrams, carrier distribution and recombination rates (Shockley-Reed-Hall, Auger, and radiative recombination rates) in the quantum well, under equilibrium and forward bias conditions. Electron blocking layer is based on AlaGa1-aN / Al b → cGa1-b → 1-cN / AldGa 1-dN, where a < d < b < c. A graded layer sandwiched between large bandgap AlGaN materials was found to be effective in simultaneously blocking electrons and providing polarization field enhanced carrier injection. The graded interlayer reduces polarization induced band bending and mitigates the related drawback of impediment of holes injection. Similarly on the n-side, the Alx → yGa1-x → 1-yN / AlzGa 1-zN (x < z < y) barrier acts as a hole blocking layer. The reduced carrier leakage and enhanced carrier density in the active region results in significant improvement in radiative recombination rate compared to a structure with the conventional rectangular EBL layers. The improvement in device performance comes from meticulously designing the hole and electron blocking layers to increase carrier injection efficiency. The quantum well based UV-LED was designed to emit at 280nm, which is an effective wavelength for water disinfection application.

  4. Advanced capabilities and applications of a sputter-RBS system

    International Nuclear Information System (INIS)

    Brijs, B.; Deleu, J.; Beyer, G.; Vandervorst, W.

    1999-01-01

    In previous experiments, sputter-RBS 1 has proven to be an ideal tool to study the interaction of low energy ions. This contribution employs the same methodology to identify surface contamination induced during sputtering and to the determine absolute sputter yields. In the first experiment ERDA analysis was used to study the evolution of Hydrogen contamination during sputter-RBS experiments. Since the determination of Hydrogen concentration in very thin near surface layers is frequently limited by the presence of a strong surface peak of Hydrogen originating from adsorbed contamination of the residual vacuum, removal of this contamination would increase the sensitivity for Hydrogen detection in the near sub surface drastically. Therefore low energy (12 keV) Argon sputtering was used to remove the Hydrogen surface peak. However enhanced Hydrogen adsorption was observed related to the Ar dose. This experiment shows that severe vacuum conditions and the use of high current densities/sputter yields are a prerequisite for an efficient detection of Hydrogen in the near surface layers. In the second experiment, an attempt was made to determine the sputter yield of Cu during low energy (12 keV) Oxygen bombardment. In order to determine the accumulated dose of the low energy ion beam, a separate Faraday cup in combination with a remote controlled current have been added to the existing sputter-RBS set-up. Alternating sputtering and RBS analysis seem to be an adequate tool for the determination of the absolute sputter yield of Cu and this as well in the as under steady state conditions

  5. Inorganic-Organic Nanohybrid Materials of Layered Zinc Hydroxide Nitrate with Intercalated Salicylate: Preparation, Characterization and UV-Blocking Properties

    Science.gov (United States)

    Liu, Jiexiang; Zhang, Yongqing; Zhang, Xiaoguang

    2016-02-01

    Intercalation of salicylate (Sal) into layered zinc hydroxide nitrate (ZHN) nanohybrid materials was successfully synthesized by the coprecipitation method. The effect of pH, crystallization method, temperature and time of hydrothermal treatment on preparation was investigated in detail and compared. The products were confirmed by X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR), thermogravimetry and differential thermal analysis (TG-DTA), and scanning electron microscope (SEM). The results revealed that ZHN-Sal with pure phase and good crystallinity was obtained at pH = 6.0-6.5, 60∘C and 3h of temperature and time of hydrothermal treatment. The TG-DTA data indicated that the intercalated Sal had a high stability compared to the isolated. And the phases and compositions of the sample calcined at increasing temperatures were also identified by XRPD and FTIR techniques. Furthermore, ZHN-Sal exhibited an improved UV-blocking ability, showing it can be used as a potential alternative matrix for the UV blocker.

  6. The reliability analysis of GaN-based light-emitting diodes with different current-blocking layers

    International Nuclear Information System (INIS)

    Chiou, Y Z; Chiang, T H; Kuo, D S; Chang, S J; Ko, T K; Hon, S J

    2011-01-01

    This study employed Ar plasma treatment to selectively damage the p-GaN surface under the p-pad electrode as a current-blocking layer (CBL) on nitride-based light-emitting diodes (LEDs). Increasing the resistivity of the p-GaN region under the p-pad electrode can reduce the current flowing vertically downward from the p-pad electrode. At an injection current of 20 mA, the light output power of LEDs with Ar plasma treatment was 13% larger than that of conventional LEDs. At an injection current of 100 mA, the temperature of the p-pad metal on LEDs with Ar plasma treatment is 13 °C lower than that of the LEDs with a SiO 2 CBL. However, the electrostatic discharge endurance of LEDs with Ar plasma treatment is the worst due to the surface damage of p-GaN under the p-pad electrode

  7. A novel strategy for high-stability lithium sulfur batteries by in situ formation of polysulfide adsorptive-blocking layer

    Science.gov (United States)

    Jin, Liming; Li, Gaoran; Liu, Binhong; Li, Zhoupeng; Zheng, Junsheng; Zheng, Jim P.

    2017-07-01

    Lithium sulfur (Lisbnd S) batteries are one of the most promising energy storage devices owing to their high energy and power density. However, the shuttle effect as a key barrier hinders its practical application by resulting in low coulombic efficiency and poor cycling performance. Herein, a novel design of in situ formed polysulfide adsorptive-blocking layer (PAL) on the cathode surface was developed to tame the polysulfide shuttling and promote the cycling stability for Lisbnd S batteries. The PAL is consisted of La2S3, which is capable to chemically adsorb polysulfide via the strong interaction of Lasbnd S bond and Ssbnd S bond, and build an effective barrier against sulfur escaping. Moreover, the La2S3 is capable to suppress the crystallization of Li2S and promote the ion transfer, which contributes to the reduced internal resistance of batteries. Furthermore, the by-product LiNO3 simultaneously forms a stable anode solid and electrolyte interface to further inhibit the polysulfide shuttle. By this simple and convenient method, the resultant Lisbnd S batteries achieved exceptional cycling stability with an ultralow decay rate of 0.055% since the 10th cycle.

  8. Enhancement of Endurance in HfO2-Based CBRAM Device by Introduction of a TaN Diffusion Blocking Layer

    KAUST Repository

    Chand, Umesh

    2017-08-05

    We propose a new method to improve resistive switching properties in HfO2 based CBRAM crossbar structure device by introducing a TaN thin diffusion blocking layer between the Cu top electrode and HfO2 switching layer. The Cu/TaN/HfO2/TiN device structure exhibits high resistance ratio of OFF/ON states without any degradation in switching during endurance test. The improvement in the endurance properties of the Cu/TaN/HfO2/TiN CBRAM device is thus attributed to the relatively low amount of Cu migration into HfO2 switching layer.

  9. Effect of organic-buffer-layer on electrical property and environmental reliability of Ga-doped ZnO films prepared by RF plasma assisted DC magnetron sputtering on plastic substrate

    International Nuclear Information System (INIS)

    Hinoki, Toshio; Kyuhara, Chika; Agura, Hideaki; Yazawa, Kenji; Kinoshita, Kentaro; Ohmi, Koutoku; Kishida, Satoru

    2010-01-01

    Ga-doped ZnO (GZO) transparent conductive films have been prepared by RF plasma assisted DC magnetron sputtering under a reductive atmosphere on organic-buffer-layer (OBL) coated polyethylene telephthalate (PET) substrates without intentionally heating substrates. Electrical and optical properties, crystallinity, and environmental reliability of the GZO films have been investigated. The distributional characteristic of resistivity is observed in the GZO film deposited on the OBL-coated PET substrates. The high resistivity at facing the erosion area in the source target is reduced by providing the RF plasma and H 2 gas near the substrate, resulting in a uniform distribution of the sheet resistance. It has been also found that the increase of resistivity by an accelerated aging test performed under a storage condition at 60 o C and at a relative humidity of 95% is suppressed by employing the OBL. The OBL suppresses the formation of cracks, which are induced by the aging test. These facts are thought to contribute to a high environmental reliability of GZO films on PET substrates. Values of resistivity, Hall mobility and carrier concentration are obtained: 5.0-20 x 10 -3 Ω cm, 4.0 cm 2 /Vs, and 3.8 x 10 20 cm -3 , respectively. An average transmittance of the GZO film including OBL and PET substrate is 78% in a visible region. The OBL enables to realize the practical use of GZO films on PET sheets.

  10. Synergistic sputtering properties of binary alloys

    International Nuclear Information System (INIS)

    Krauss, A.R.; DeWald, A.B.; Gruen, D.M.; Lam, N.Q.

    1984-01-01

    We have found that dilute concentrations of lithium in copper produce surfaces which are nearly pure lithium when heated and subject to irradiation. In order to better understand the experimental results, we have modeled the Cu-Li system using a modified version of the TRIM computer code and an alloy segregation program developed by N.Q. Lam. The TRIM code calculates the sputtering yield and depth of origin of the sputtered atoms for materials in which the composition varies from one atomic layer to the next and the segregation program uses these sputtering yields to trace the evolution of the concentration profile. The initial result of sputtering is to preferentially deplete the surface species. Continued irradiation, however, creates a subsurface region of high displacement damage. In the Cu-Li alloy, lithium moves very rapidly through this region, resulting in subsurface lithium enrichment. The enriched region broadens and eventually reaches the surface. The exact effect on the lithium concentration in the first two atomic layers depends on the temperature, damage profile, and particle flux. Results of the calculation are presented, along with a discussion of their implications for fusion reactor materials

  11. Reactive dual magnetron sputtering for large area application

    International Nuclear Information System (INIS)

    Struempfel, J.

    2002-01-01

    Production lines for large area coating demand high productivity of reactive magnetron sputtering processes. Increased dynamic deposition rates for oxides and nitrides were already obtained by using of highly powered magnetrons in combination with advanced sputter techniques. However, besides high deposition rates the uniformity of such coatings has to be carefully considered. First the basics of reactive sputtering processes and dual magnetron sputtering are summarized. Different methods for process stabilization and control are commonly used for reactive sputtering. The Plasma Emission Monitor (PE M) offers the prerequisite for fast acting process control derived from the in-situ intensity measurements of a spectral line of the sputtered target material. Combined by multiple Plasma Emission Monitor control loops segmented gas manifolds are able to provide excellent thin film uniformity at high deposition rates. The Dual Magnetron allows a broad range of processing by different power supply modes. Medium frequency, DC and pulsed DC power supplies can be used for high quality layers. Whereas the large area coating of highly isolating layers like TiO 2 or SiO 2 is dominated by MF sputtering best results for coating with transparent conductive oxides are obtained by dual DC powering of the dual magnetron arrangement. (Author)

  12. Grafting of Gold Nanoparticles on Glass Using Sputtered Gold Interlayers

    OpenAIRE

    Kvítek, Ondřej; Hendrych, Robin; Kolská, Zdeňka; Švorčík, Václav

    2014-01-01

    Three-step preparation of nanostructured Au layer on glass substrate is described. The procedure starts with sputtered gold interlayer, followed by grafting with dithiols and final coverage with gold nanoparticles (AuNPs). Successful binding of dithiols on the sputtered Au film was confirmed by X-ray photoelectron spectroscopy measurement. AuNPs bound to the surface were observed using atomic force microscopy. Both single nanoparticles and their aggregates were observed. UV-Vis spectra show b...

  13. Influence of Nb-doped TiO2 blocking layers as a cascading band structure for enhanced photovoltaic properties

    Science.gov (United States)

    Koo, Bon-Ryul; Oh, Dong-Hyeun; Ahn, Hyo-Jin

    2018-03-01

    Nb-doped TiO2 (Nb-TiO2) blocking layers (BLs) were developed using horizontal ultrasonic spray pyrolysis deposition (HUSPD). In order to improve the photovoltaic properties of the dye-sensitized solar cells (DSSCs), we optimized the Nb doping level of the Nb-TiO2 BLs by controlling the Nb/Ti molar ratio (0, 5, 6, and 7) of the precursor solution for HUSPD. Compared to bare TiO2 BLs, the Nb-TiO2 BLs formed a cascading band structure using the positive shift of the conduction band minimum of the Nb-TiO2 positioned between fluorine-doped tin oxide (FTO) and TiO2. This results in the increase of the potential current and the suppression of the electron recombination. Hence, it led to the improvement of the electrical conductivity, due to the increased electron concentration by the Nb doping into TiO2. Therefore, the DSSC fabricated with the Nb-TiO2 BLs at a Nb/Ti molar ratio of 6 showed superior photoconversion efficiency (∼7.50 ± 0.20%) as a result of the improved short-circuit current density. This is higher than those with the other Nb-TiO2 BLs and without BL. This improvement of the photovoltaic properties for the DSSCs can be attributed to the synergistic effects of uniform and compact BL relative to the prevention of the backward electron transport at the FTO/electrolyte interface, efficient electron transport at interfaces relative to a cascading band structure of FTO/Nb-TiO2/TiO2 multilayers and the facilitated electron transport at the BLs relative to the increased electrical conductivity of the optimized Nb-TiO2 BLs.

  14. The influence of anatase-rutile mixed phase and ZnO blocking layer on dye-sensitized solar cells based on TiO2nanofiberphotoanodes

    Science.gov (United States)

    Ding, Jianning; Li, Yan; Hu, Hongwei; Bai, Li; Zhang, Shuai; Yuan, Ningyi

    2013-01-01

    High performance is expected in dye-sensitized solar cells (DSSCs) that utilize one-dimensional (1-D) TiO2 nanostructures owing to the effective electron transport. However, due to the low dye adsorption, mainly because of their smooth surfaces, 1-D TiO2 DSSCs show relatively lower efficiencies than nanoparticle-based ones. Herein, we demonstrate a very simple approach using thick TiO2 electrospun nanofiber films as photoanodes to obtain high conversion efficiency. To improve the performance of the DSCCs, anatase-rutile mixed-phase TiO2 nanofibers are achieved by increasing sintering temperature above 500°C, and very thin ZnO films are deposited by atomic layer deposition (ALD) method as blocking layers. With approximately 40-μm-thick mixed-phase (approximately 15.6 wt.% rutile) TiO2 nanofiber as photoanode and 15-nm-thick compact ZnO film as a blocking layer in DSSC, the photoelectric conversion efficiency and short-circuit current are measured as 8.01% and 17.3 mA cm-2, respectively. Intensity-modulated photocurrent spectroscopy and intensity-modulated photovoltage spectroscopy measurements reveal that extremely large electron diffusion length is the key point to support the usage of thick TiO2 nanofibers as photoanodes with very thin ZnO blocking layers to obtain high photocurrents and high conversion efficiencies.

  15. Argon Cluster Sputtering Source for ToF-SIMS Depth Profiling of Insulating Materials: High Sputter Rate and Accurate Interfacial Information

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhaoying; Liu, Bingwen; Zhao, Evan; Jin, Ke; Du, Yingge; Neeway, James J.; Ryan, Joseph V.; Hu, Dehong; Zhang, Hongliang; Hong, Mina; Le Guernic, Solenne; Thevuthasan, Suntharampillai; Wang, Fuyi; Zhu, Zihua

    2015-08-01

    For the first time, the use of an argon cluster ion sputtering source has been demonstrated to perform superiorly relative to traditional oxygen and cesium ion sputtering sources for ToF-SIMS depth profiling of insulating materials. The superior performance has been attributed to effective alleviation of surface charging. A simulated nuclear waste glass, SON68, and layered hole-perovskite oxide thin films were selected as model systems due to their fundamental and practical significance. Our study shows that if the size of analysis areas is same, the highest sputter rate of argon cluster sputtering can be 2-3 times faster than the highest sputter rates of oxygen or cesium sputtering. More importantly, high quality data and high sputter rates can be achieved simultaneously for argon cluster sputtering while this is not the case for cesium and oxygen sputtering. Therefore, for deep depth profiling of insulating samples, the measurement efficiency of argon cluster sputtering can be about 6-15 times better than traditional cesium and oxygen sputtering. Moreover, for a SrTiO3/SrCrO3 bi-layer thin film on a SrTiO3 substrate, the true 18O/16O isotopic distribution at the interface is better revealed when using the argon cluster sputtering source. Therefore, the implementation of an argon cluster sputtering source can significantly improve the measurement efficiency of insulating materials, and thus can expand the application of ToF-SIMS to the study of glass corrosion, perovskite oxide thin films, and many other potential systems.

  16. Ion beam sputter implantation method

    International Nuclear Information System (INIS)

    King, W.J.

    1978-01-01

    By means of ion beam atomizing or sputtering an integrally composed coating, the composition of which continuously changes from 100% of the substrate to 100% of the coating, can be surfaced on a substrate (e.g. molten quartz on plastic lenses). In order to do this in the facility there is directed a primary beam of accelerated noble gas ions on a target from the group of the following materials: SiO 2 , Al 2 O 3 , Corning Glass 7070, Corning Glass 7740 or borosilicate glass. The particles leaving the target are directed on the substrate by means of an acceleration potential of up to 10 KV. There may, however, be coated also metal layers (Ni, Co) on a mylar film resulting in a semireflecting metal film. (RW) [de

  17. Transport theory of sputtering I: Depth of origin of sputtered atoms

    International Nuclear Information System (INIS)

    Zhang, Z.L.

    1999-01-01

    Sputter theory employing a sum of two power cross sections has been implemented. Compared with the well known Lindhard power cross section (V∝r -1/m ), a sum of two such cross sections can give a much better approximation to the Born-Mayer scattering in the low energy region (m ∼ 0.1). By using both one and two power cross sections, we have solved the linear transport equations describing the sputtering problem asymptotically. As usual, electronic stopping is ignored in the analysis. It has further been proved that Falcone's theory of the atom ejection process contradicts transport theory. The Andersen-Sigmund relation for partial sputtering yield ratios between two elements in an arbitrary multicomponent target has been derived by both methods. The energy deposited in the target surface layers has been computed for a few typical ion-target combinations. The numerical curves show that both theories generate almost the same results (error <10%) for m=3D0.2. It is also shown that, if the sputtering yield equals the corresponding one in Sigmund's theory, the depth of origin of sputtered atoms must be shorter than in Sigmund's theory for 0.25 m ≥ 3D 0. The former even may be only about one half of the latter as long as m=3D0. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  18. Residual stress in magnetron sputtered TiN

    NARCIS (Netherlands)

    Zoestbergen, E; de Hosson, J.T.M.; Brebbia, CA; Kenny, JM

    1999-01-01

    In this study magnetron sputtered TiN layers are investigated with X-ray diffraction. The measurements show that there is a texture present and in these layers a non-linear d-sin(2)psi behavior for the (200) planes was found. The latter cannot be explained by the well-known causes that may generate

  19. Proton sputtering. Final report

    International Nuclear Information System (INIS)

    Finfgeld, C.R.

    1975-01-01

    This research provides sputtering yields as a function of energy for H + and D + on several representative pure metallic elements, in the absence of surface contaminants. The experimental technique and apparatus are described. Data are given for Au, Co, Ta, W, and Mo

  20. Data Retention Characterization of Gate-Injected Gold-Nanoparticle Non-Volatile Memory with Low-Damage CF4-Plasma-Treated Blocking Oxide Layer

    Directory of Open Access Journals (Sweden)

    Yu-Hua Liu

    2017-11-01

    Full Text Available Gold-nanoparticle (Au-NP non-volatile memories (NVMs with low-damage CF4 plasma treatment on the blocking oxide (BO layer have been investigated to present the gate injection of the holes. These holes, injected from the Al gate with the positive gate bias, were explained by the bandgap engineering of the gradually-fluorinated BO layer and the effective work function modulation of the Al gate. The Si–F complex in the BO layer was analyzed by X-ray photoelectron spectroscopy (XPS, while the depth of fluorine incorporation was verified using a secondary ion mass spectrometer (SIMS. In addition, the valence band modification of the fluorinated BO layer was examined by ultraviolet photoelectron spectroscopy (UPS to support the bandgap engineering. The reactive power of the CF4 plasma treatment on the BO layer was modified to increase the electric field of the BO layer and raise the effective work function of the Al gate, leading to the hole-injection from the gate. The injected holes are trapped at the interface between the gold-nanoparticles (Au-NPs and the tunneling oxide (TO layer, resulting in superior data retention properties such as an extremely low charge loss of 5.7% at 104 s and a nearly negligible increase in charge loss at 85 °C of the CF4-plasma-treated Au-NP NVMs, which can be applied in highly reliable consumer electronics.

  1. Data Retention Characterization of Gate-Injected Gold-Nanoparticle Non-Volatile Memory with Low-Damage CF₄-Plasma-Treated Blocking Oxide Layer.

    Science.gov (United States)

    Liu, Yu-Hua; Kao, Chyuan-Haur; Cheng, Tsung-Chin; Wu, Chih-I; Wang, Jer-Chyi

    2017-11-10

    Gold-nanoparticle (Au-NP) non-volatile memories (NVMs) with low-damage CF₄ plasma treatment on the blocking oxide (BO) layer have been investigated to present the gate injection of the holes. These holes, injected from the Al gate with the positive gate bias, were explained by the bandgap engineering of the gradually-fluorinated BO layer and the effective work function modulation of the Al gate. The Si-F complex in the BO layer was analyzed by X-ray photoelectron spectroscopy (XPS), while the depth of fluorine incorporation was verified using a secondary ion mass spectrometer (SIMS). In addition, the valence band modification of the fluorinated BO layer was examined by ultraviolet photoelectron spectroscopy (UPS) to support the bandgap engineering. The reactive power of the CF₄ plasma treatment on the BO layer was modified to increase the electric field of the BO layer and raise the effective work function of the Al gate, leading to the hole-injection from the gate. The injected holes are trapped at the interface between the gold-nanoparticles (Au-NPs) and the tunneling oxide (TO) layer, resulting in superior data retention properties such as an extremely low charge loss of 5.7% at 10⁴ s and a nearly negligible increase in charge loss at 85 °C of the CF₄-plasma-treated Au-NP NVMs, which can be applied in highly reliable consumer electronics.

  2. Fluence-dependent sputtering yield of micro-architectured materials

    Energy Technology Data Exchange (ETDEWEB)

    Matthes, Christopher S.R.; Ghoniem, Nasr M., E-mail: ghoniem@ucla.edu; Li, Gary Z.; Matlock, Taylor S.; Goebel, Dan M.; Dodson, Chris A.; Wirz, Richard E.

    2017-06-15

    Highlights: • Sputtering yield is shown to be transient and heavily dependent on surface architecture. • Fabricated nano- and Microstructures cause geometric re-trapping of sputtered material, which leads to a self-healing mechanism. • Initially, the sputtering yield of micro-architectured Mo is approximately 1/2 the value as that of a planar surface. • The study demonstrates that the sputtering yield is a dynamic property, dependent on the surface structure of a material. • A developed phenomenological model mathematically describes the transient behavior of the sputtering yield as a function of plasma fluence. - Abstract: We present an experimental examination of the relationship between the surface morphology of Mo and its instantaneous sputtering rate as function of low-energy plasma ion fluence. We quantify the dynamic evolution of nano/micro features of surfaces with built-in architecture, and the corresponding variation in the sputtering yield. Ballistic deposition of sputtered atoms as a result of geometric re-trapping is observed, and re-growth of surface layers is confirmed. This provides a self-healing mechanism of micro-architectured surfaces during plasma exposure. A variety of material characterization techniques are used to show that the sputtering yield is not a fundamental property, but that it is quantitatively related to the initial surface architecture and to its subsequent evolution. The sputtering yield of textured molybdenum samples exposed to 300 eV Ar plasma is roughly 1/2 of the corresponding value for flat samples, and increases with ion fluence. Mo samples exhibited a sputtering yield initially as low as 0.22 ± 5%, converging to 0.4 ± 5% at high fluence. The sputtering yield exhibits a transient behavior as function of the integrated ion fluence, reaching a steady-state value that is independent of initial surface conditions. A phenomenological model is proposed to explain the observed transient sputtering phenomenon, and to

  3. Broadband pH-Sensing Organic Transistors with Polymeric Sensing Layers Featuring Liquid Crystal Microdomains Encapsulated by Di-Block Copolymer Chains.

    Science.gov (United States)

    Seo, Jooyeok; Song, Myeonghun; Jeong, Jaehoon; Nam, Sungho; Heo, Inseok; Park, Soo-Young; Kang, Inn-Kyu; Lee, Joon-Hyung; Kim, Hwajeong; Kim, Youngkyoo

    2016-09-14

    We report broadband pH-sensing organic field-effect transistors (OFETs) with the polymer-dispersed liquid crystal (PDLC) sensing layers. The PDLC layers are prepared by spin-coating using ethanol solutions containing 4-cyano-4'-pentyl-biphenyl (5CB) and a diblock copolymer (PAA-b-PCBOA) that consists of LC-philic block [poly(4-cyano-biphenyl-4-oxyundecyl acrylate) (PCBOA)] and acrylic acid block [poly(acrylic acid) (PAA)]. The spin-coated sensing layers feature of 5CB microdomains (OFETs (PDLC-i-OFETs) can detect precisely and reproducibly a wide range of pH with only small amounts (10-40 μL) of analyte solutions in both static and dynamic perfusion modes. The positive drain current change is measured for acidic solutions (pH 7) result in the negative change of drain current. The drain current trend in the present PDLC-i-OFET devices is explained by the shrinking-expanding mechanism of the PAA chains in the diblock copolymer layers.

  4. Enhanced charge collection with ultrathin AlOx electron blocking layer for hole-transporting material-free perovskite solar cell.

    Science.gov (United States)

    Wei, Huiyun; Shi, Jiangjian; Xu, Xin; Xiao, Junyan; Luo, Jianheng; Dong, Juan; Lv, Songtao; Zhu, Lifeng; Wu, Huijue; Li, Dongmei; Luo, Yanhong; Meng, Qingbo; Chen, Qiang

    2015-02-21

    An ultrathin AlOx layer has been deposited onto a CH3NH3PbI3 film using atomic layer deposition technology, to construct a metal-insulator-semiconductor (MIS) back contact for the hole-transporting material-free perovskite solar cell. By optimization of the ALD deposition cycles, the average power conversion efficiency (PCE) of the cell has been enhanced from 8.61% to 10.07% with a highest PCE of 11.10%. It is revealed that the improvement in cell performance with this MIS back contact is mainly attributed to the enhancement in charge collection resulting from the electron blocking effect of the AlOx layer.

  5. Cross-Layer Framework for Multiuser Real Time H.264/AVC Video Encoding and Transmission over Block Fading MIMO Channels Using Outage Probability

    Directory of Open Access Journals (Sweden)

    Slavche Pejoski

    2014-01-01

    Full Text Available We present a framework for cross-layer optimized real time multiuser encoding of video using a single layer H.264/AVC and transmission over MIMO wireless channels. In the proposed cross-layer adaptation, the channel of every user is characterized by the probability density function of its channel mutual information and the performance of the H.264/AVC encoder is modeled by a rate distortion model that takes into account the channel errors. These models are used during the resource allocation of the available slots in a TDMA MIMO communication system with capacity achieving channel codes. This framework allows for adaptation to the statistics of the wireless channel and to the available resources in the system and utilization of the multiuser diversity of the transmitted video sequences. We show the effectiveness of the proposed framework for video transmission over Rayleigh MIMO block fading channels, when channel distribution information is available at the transmitter.

  6. Tutorial: Reactive high power impulse magnetron sputtering (R-HiPIMS)

    Science.gov (United States)

    Anders, André

    2017-05-01

    High Power Impulse Magnetron Sputtering (HiPIMS) is a coating technology that combines magnetron sputtering with pulsed power concepts. By applying power in pulses of high amplitude and a relatively low duty cycle, large fractions of sputtered atoms and near-target gases are ionized. In contrast to conventional magnetron sputtering, HiPIMS is characterized by self-sputtering or repeated gas recycling for high and low sputter yield materials, respectively, and both for most intermediate materials. The dense plasma in front of the target has the dual function of sustaining the discharge and providing plasma-assistance to film growth, affecting the microstructure of growing films. Many technologically interesting thin films are compound films, which are composed of one or more metals and a reactive gas, most often oxygen or nitrogen. When reactive gas is added, non-trivial consequences arise for the system because the target may become "poisoned," i.e., a compound layer forms on the target surface affecting the sputtering yield and the yield of secondary electron emission and thereby all other parameters. It is emphasized that the target state depends not only on the reactive gas' partial pressure (balanced via gas flow and pumping) but also on the ion flux to the target, which can be controlled by pulse parameters. This is a critical technological opportunity for reactive HiPIMS (R-HiPIMS). The scope of this tutorial is focused on plasma processes and mechanisms of operation and only briefly touches upon film properties. It introduces R-HiPIMS in a systematic, step-by-step approach by covering sputtering, magnetron sputtering, reactive magnetron sputtering, pulsed reactive magnetron sputtering, HiPIMS, and finally R-HiPIMS. The tutorial is concluded by considering variations of R-HiPIMS known as modulated pulsed power magnetron sputtering and deep-oscillation magnetron sputtering and combinations of R-HiPIMS with superimposed dc magnetron sputtering.

  7. Mechanical and structural properties of sputtered Ni/Ti multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Senthil Kumar, M.; Boeni, P.; Tixier, S.; Clemens, D.; Horisberger, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Ni/Ti bilayers have been prepared by dc-magnetron sputtering in order to study their mechanical and structural properties. A remarkable reduction of stress is observed when the Ni layers are sputtered reactively in argon with a high partial pressure of air. The high angle x-ray diffraction studies show a tendency towards amorphisation of the Ni layers with increasing air flow. The low angle measurements indicate a substantial reduction of interdiffusion resulting in smoother interfaces with increasing air content. (author) 2 figs., 2 refs.

  8. Morphology, microstructure, and hardness of titanium (Ti-6Al-4V) blocks deposited by wire-feed additive layer manufacturing (ALM)

    International Nuclear Information System (INIS)

    Brandl, Erhard; Schoberth, Achim; Leyens, Christoph

    2012-01-01

    Highlights: ► The microstructure and hardness of deposited Ti-6Al-4V blocks are investigated. ► Hardness is influenced by post heat treatment rather than by process parameters. ► Microstructure within the prior β-grains varies to some extent from grain to grain. ► A 600 °C/4 h treatment significantly increased the average hardness. - Abstract: Additive layer manufacturing offers a potential for time and cost savings, especially for aerospace components made from costly titanium alloys. In this paper, the morphology, microstructure, chemical composition, and hardness of additive manufactured Ti-6Al-4V blocks are investigated and discussed. Blocks (7 beads wide, 7 layers high) were deposited using Ti-6Al-4V wire and a Nd:YAG laser. Two different sets of parameters are used and three different post heat treatment conditions (as-built, 600 °C/4 h, 1200 °C/2 h) are investigated. The experiments reveal elementary properties of additive manufactured Ti-6Al-4V material in correlation to process parameters and heat treatments, which are discussed comprehensively.

  9. Energy dependence of sputtering yields of Be, Be-C and Be-W films by Be{sup +}-ions

    Energy Technology Data Exchange (ETDEWEB)

    Korshunov, S.N.; Guseva, M.I.; Gureev, V.M.; Neumoin, V.E.; Stoljarova, V.G. [Russian Research Center Kurchatov Inst., Moscow (Russian Federation)

    1998-01-01

    The energy dependence measurements of Be, Be-C and Be-W deposited layer sputtering yields by Be{sup +}-ions were performed. The ion energy was varied in the range (0.3-5.0) keV. The temperature in the process of irradiation was sustained at the level of 670 K. The mixed layers were prepared by simultaneous sputtering of pair targets, Be and C, Be and W, and Be-targets with Ar{sup +}- and Be{sup +}-ions and codeposition of the sputtered atoms on silicon collectors The codeposited layer thickness was changed in the range of (500-1000) nm. The content of oxigen in the Be, Be-C, Be-W deposited layers did not exceed 20 at.%. The mixed layer sputtering yields were compared with the experimental and calculated data, obtained for the self-sputtering yields of beryllium and carbon. It was found that the sputtering yields of the Be-C and Be deposited layers by Be{sup +}-ions in the energy range (0.3-5.0) keV are within the range between the corresponding self-sputtering yields for Be and C. The sputtering yields for the mixture Be-W are close to the corresponding self-sputtering yields of beryllium. (author)

  10. Influence of the surface topography, morphology and structure on magnetic properties of ion beam sputtered iron layers, Fe/Cr/Fe- and Fe/MgO/Fe multilayers; Untersuchung der Morphologie und magnetische Eigenschaften von ionenstrahl-gesputterten Eisen-Einzelschichten, Fe/Cr/Fe- und Fe/MgO/Fe-Schichtsystemen

    Energy Technology Data Exchange (ETDEWEB)

    Steeb, Alexandra

    2007-04-05

    In this PhD Thesis, the influence of the surface topography, morphology and structure on magnetic properties of ion beam sputtered iron layers on GaAs is examined. To analyze the structure of the produced iron films, low energy electron diffraction and scanning tunneling microscopy is employed. The utilized methods to investigate the magnetic properties are Kerr- and SQUID-magnetometry and ferromagnetic resonance. It is demonstrated that on untreated as well as on presputtered and heated GaAs substrates the sputtered iron films grow epitaxially. The least surface roughness of 1 A exhibit iron films grown on untreated GaAs, while iron films on heated GaAs have the highest roughness of 30 A. The largest crystal anisotropy constant is found for the presputtered GaAs/Fe-System. For this preparation method, two monolayers of iron are determined to be magnetically dead layers. At a film thickness of 100 A, 83% of the value for saturation magnetization of bulk iron are achieved. The small observed FMR-linewidths confirm the good bulk properties of the ion beam sputtered iron. Furthermore, an antiferromagnetic interlayer exchange coupling in sputtered Fe/Cr/Fe-films was achieved. For a thickness of 12 to 17 A of the chrome interlayer, a coupling strength up to 0.2 mJ/m{sup 2} is found. To account for the small coupling strength, a strong intermixing at the interface is assumed. Finally, epitaxial Fe/MgO/Fe/FeMn multilayers are deposited on GaAs. After the structuring, it is possible to detect tunneling processes in the tunneling contacts with current-voltage measurements. The tunnel magneto resistance values of 2% are small, which can be explained by the absence of sharp, well-defined interfaces between the Fe/FeMn and the Fe/MgO interfaces. These results demonstrate, that analog to MBE the ion beam sputtering method realizes good magnetic bulk properties. However, interface sensitive phenomena are weakened because of a strong intermixing at the interfaces. (orig.)

  11. A tribo-mechanical analysis of PVA-based building-blocks for implementation in a 2-layered skin model

    NARCIS (Netherlands)

    Morales Hurtado, Marina; de Vries, Erik G.; Zeng, Xiangqiong; van der Heide, Emile

    2016-01-01

    Poly(vinyl) alcohol hydrogel (PVA) is a well-known polymer widely used in the medical field due to its biocompatibility properties and easy manufacturing. In this work, the tribo-mechanical properties of PVA-based blocks are studied to evaluate their suitability as a part of a structure simulating

  12. Simple model of surface roughness for binary collision sputtering simulations

    International Nuclear Information System (INIS)

    Lindsey, Sloan J.; Hobler, Gerhard; Maciążek, Dawid; Postawa, Zbigniew

    2017-01-01

    Highlights: • A simple model of surface roughness is proposed. • Its key feature is a linearly varying target density at the surface. • The model can be used in 1D/2D/3D Monte Carlo binary collision simulations. • The model fits well experimental glancing incidence sputtering yield data. - Abstract: It has been shown that surface roughness can strongly influence the sputtering yield – especially at glancing incidence angles where the inclusion of surface roughness leads to an increase in sputtering yields. In this work, we propose a simple one-parameter model (the “density gradient model”) which imitates surface roughness effects. In the model, the target’s atomic density is assumed to vary linearly between the actual material density and zero. The layer width is the sole model parameter. The model has been implemented in the binary collision simulator IMSIL and has been evaluated against various geometric surface models for 5 keV Ga ions impinging an amorphous Si target. To aid the construction of a realistic rough surface topography, we have performed MD simulations of sequential 5 keV Ga impacts on an initially crystalline Si target. We show that our new model effectively reproduces the sputtering yield, with only minor variations in the energy and angular distributions of sputtered particles. The success of the density gradient model is attributed to a reduction of the reflection coefficient – leading to increased sputtering yields, similar in effect to surface roughness.

  13. Molecular dynamic simulations of the sputtering of multilayer organic systems

    CERN Document Server

    Postawa, Z; Piaskowy, J; Krantzman, K; Winograd, N; Garrison, B J

    2003-01-01

    Sputtering of organic overlayers has been modeled using molecular dynamics computer simulations. The investigated systems are composed of benzene molecules condensed into one, two and three layers on an Ag left brace 1 1 1 right brace surface. The formed organic overlayers were bombarded with 4 keV Ar projectiles at normal incidence. The development of the collision cascade in the organic overlayer was investigated. The sputtering yield, mass, internal and kinetic energy distributions of ejected particles have been analyzed as a function of the thickness of the organic layer. The results show that all emission characteristics are sensitive to the variation of layer thickness. Although most of the ejected intact benzene molecules originate from the topmost layer, the emission of particles located initially in second and third layers is significant. The analysis indicates that the metallic substrate plays a dominant role in the ejection of intact organic molecules.

  14. Laser spectroscopy of sputtered atoms

    International Nuclear Information System (INIS)

    Gruen, D.M.; Pellin, M.J.; Young, C.E.; Calaway, W.F.

    1985-01-01

    The use of laser radiation to study the sputtering process is of relatively recent origin. Much has been learned from this work about the basic physics of the sputtering process itself through measurements of velocity and excited state distributions of sputtered atoms and the effects of adsorbates on substrate sputtering yields. Furthermore, the identification, characterization, and sensitive detection of sputtered atoms by laser spectroscopy has led to the development of in situ diagnostics for impurity fluxes in the plasma edge regions of tokamaks and of ultrasensitive methods (ppB Fe in Si) for surface analysis with ultralow (picocoulomb) ion fluences. The techniques involved in this work, laser fluorescence and multiphoton resonance ionization spectroscopy, will be described and illustrations given of results achieved up to now. 55 refs., 5 figs., 1 tab

  15. RF Reactive Magnetron Sputter Deposition of Silicon Sub-Oxides

    NARCIS (Netherlands)

    Hattum, E.D. van

    2007-01-01

    RF reactive magnetron plasma sputter deposition of silicon sub oxide E.D. van Hattum Department of Physics and Astronomy, Faculty of Sciences, Utrecht University The work described in the thesis has been inspired and stimulated by the use of SiOx layers in the direct inductive printing technology,

  16. Modular design of AFM probe with sputtered silicon tip

    DEFF Research Database (Denmark)

    Rasmussen, Peter; Thaysen, Jacob; Bouwstra, Siebe

    2001-01-01

    of the thin films constituting the cantilever. The AFM probe has an integrated tip made of a thick sputtered silicon layer, which is deposited after the probe has been defined and just before the cantilevers are released. The tips are so-called rocket tips made by reactive ion etching. We present probes...

  17. Development of the sputter coater for hotcell

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Yong Bum; Kwon, H. M.; Chun, Y. B.; Yang, Y. S.; Joo, J. S.; Jang, N. M

    2007-05-15

    In last december, the Wavelength Dispersive Spectroscopy (WDS) was installed on the shielded SEM of PIEF, KAERI. Before the first major WDS analysis service at the end of 2007, one among the prior technologies, the hot-cell sputter coater was remodelled from a commercial product and set up inside the glove box. This report describes effects of a coating layer on quantitative analysis, the remodelling of a coater suited to hot-cell, and the performance test of the remodelled coater. Also, written in 1998 was revised and appended to the report.

  18. Building blocks for the development of an interface for high-throughput thin layer chromatography/ambient mass spectrometric analysis: a green methodology.

    Science.gov (United States)

    Cheng, Sy-Chyi; Huang, Min-Zong; Wu, Li-Chieh; Chou, Chih-Chiang; Cheng, Chu-Nian; Jhang, Siou-Sian; Shiea, Jentaie

    2012-07-17

    Interfacing thin layer chromatography (TLC) with ambient mass spectrometry (AMS) has been an important area of analytical chemistry because of its capability to rapidly separate and characterize the chemical compounds. In this study, we have developed a high-throughput TLC-AMS system using building blocks to deal, deliver, and collect the TLC plate through an electrospray-assisted laser desorption ionization (ELDI) source. This is the first demonstration of the use of building blocks to construct and test the TLC-MS interfacing system. With the advantages of being readily available, cheap, reusable, and extremely easy to modify without consuming any material or reagent, the use of building blocks to develop the TLC-AMS interface is undoubtedly a green methodology. The TLC plate delivery system consists of a storage box, plate dealing component, conveyer, light sensor, and plate collecting box. During a TLC-AMS analysis, the TLC plate was sent to the conveyer from a stack of TLC plates placed in the storage box. As the TLC plate passed through the ELDI source, the chemical compounds separated on the plate would be desorbed by laser desorption and subsequently postionized by electrospray ionization. The samples, including a mixture of synthetic dyes and extracts of pharmaceutical drugs, were analyzed to demonstrate the capability of this TLC-ELDI/MS system for high-throughput analysis.

  19. Closed field magnetron sputtering: new generation sputtering process for optical coatings

    Science.gov (United States)

    Gibson, D. R.; Brinkley, I.; Waddell, E. M.; Walls, J. M.

    2008-09-01

    "Closed field" magnetron (CFM) sputtering offers a flexible and high throughput deposition process for optical coatings and thin films. CFM sputtering uses two or more different metal targets to deposit multilayers comprising a wide range of dielectrics, metals and conductive oxides. Moreover, CFM provides a room temperature deposition process with high ion current density, low bias voltage and reactive oxidation in the entire volume around the rotating substrate drum carrier, thereby producing films over a large surface area at high deposition rate with excellent and reproducible optical properties. Machines based on the Closed Field are scaleable to meet a range of batch and in-line size requirements. Typically, thin film thickness control to <+/-1% is accomplished simply using time, although optical monitoring can be used for more demanding applications. Fine layer thickness control and deposition of graded index layers is also assisted with a specially designed rotating shutter mechanism. This paper presents data on optical properties for CFM deposited optical coatings, including anti-reflection, thermal control filters, graded coatings, narrowband filters as well as conductive transparent oxides such as indium tin oxide and carbide films. Benefits of the CFM sputter process are described.

  20. Improvements in ANIS and inverted sputter sources

    NARCIS (Netherlands)

    Zwol, N.A. van; Vermeer, A.; Strasters, B.A.

    1984-01-01

    In this article two sputter sources, i.e. an ANIS and an inverted sputter source are described. The ANIS has been changed into a SNICS-like configuration and measurements of the output current for different sputter target geometries are presented. In the inverted sputter source an immersion lens was

  1. Sputtering of a silicon surface: Preferential sputtering of surface impurities

    Czech Academy of Sciences Publication Activity Database

    Nietiadi, M.L.; Rosandi, Y.; Lorinčík, Jan; Urbassek, H.M.

    -, č. 303 (2013), s. 205-208 ISSN 0168-583X Institutional support: RVO:67985882 Keywords : Sputtering * Molecular dynamics * SIMS Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.186, year: 2013

  2. Sputtering. [as deposition technique in mechanical engineering

    Science.gov (United States)

    Spalvins, T.

    1976-01-01

    This paper primarily reviews the potential of using the sputtering process as a deposition technique; however, the manufacturing and sputter etching aspects are also discussed. Since sputtering is not regulated by classical thermodynamics, new multicomponent materials can be developed in any possible chemical composition. The basic mechanism for dc and rf sputtering is described. Sputter-deposition is described in terms of the unique advantageous features it offers such as versatility, momentum transfer, stoichiometry, sputter-etching, target geometry (coating complex surfaces), precise controls, flexibility, ecology, and sputtering rates. Sputtered film characteristics, such as strong adherence and coherence and film morphology, are briefly evaluated in terms of varying the sputtering parameters. Also described are some of the specific industrial areas which are turning to sputter-deposition techniques.

  3. Compound La[B5O8(OH)2] with a new type of pentaborate layer based on the 5[3T + 2Δ] block: Topology-symmetry analysis and the position in the structural system

    International Nuclear Information System (INIS)

    Ivanova, A. G.; Belokoneva, E. L.; Dimitrova, O. V.; Mochenova, N. N.

    2006-01-01

    Crystals of a new rare-earth borate, LaB 5 O 8 (OH) 2 (space group P2 1 /n), are synthesized under hydrothermal conditions. The crystal structure is determined by the heavy-atom method without prior knowledge of the chemical formula. The radical anion is a layer composed of pentaborate blocks 5[3T + 2Δ]. The topological and symmetric patterns of their condensation differ from those observed in all known layered pentaborates containing the same block. The building blocks are shared by vertices of tetrahedra to form chains. These chains are joined into a corrugated layer in such a way that one of the BO 3 triangles of the building block is terminal and the layer itself is denser than those previously revealed in all other borates. In contrast to the majority of layer borates, the new La borate does not contain water molecules, because it crystallizes from more concentrated solutions. The La atoms are located inside the walls of the hollows of corrugated layers, thus centering the holes of the layers

  4. Improvements in ANIS and inverted sputter sources

    Science.gov (United States)

    Strasters, B. A.; Vermeer, A.; van Zwol, N. A.

    1984-02-01

    In this article two sputter sources, i.e. an ANIS and an inverted sputter source are described. The ANIS has been changed into a SNICS-like configuration and measurements of the output current for different sputter target geometries are presented. In the inverted sputter source an immersion lens was placed between the ionizer and the sputter target. This source is provided with a modified revolving target head with eight targets.

  5. Evidence of crystal structure in some sputtered MoS2 films.

    Science.gov (United States)

    Lavik, M. T.; Campbell, M. E.

    1972-01-01

    Electron diffraction patterns and electron micrographs of molybdenum disulfide films sputtered on single-NaCl-crystal and electropolished-aluminum substrates are presented as evidence that crystalline MoS2 films can be sputtered onto various substrates in thicknesses up to 2 microns. Applied to Falex test pins and V-blocks, some of these films exhibited a wear life as long as 65 minutes at 1000 lb jaw load.

  6. Simple model of surface roughness for binary collision sputtering simulations

    Science.gov (United States)

    Lindsey, Sloan J.; Hobler, Gerhard; Maciążek, Dawid; Postawa, Zbigniew

    2017-02-01

    It has been shown that surface roughness can strongly influence the sputtering yield - especially at glancing incidence angles where the inclusion of surface roughness leads to an increase in sputtering yields. In this work, we propose a simple one-parameter model (the "density gradient model") which imitates surface roughness effects. In the model, the target's atomic density is assumed to vary linearly between the actual material density and zero. The layer width is the sole model parameter. The model has been implemented in the binary collision simulator IMSIL and has been evaluated against various geometric surface models for 5 keV Ga ions impinging an amorphous Si target. To aid the construction of a realistic rough surface topography, we have performed MD simulations of sequential 5 keV Ga impacts on an initially crystalline Si target. We show that our new model effectively reproduces the sputtering yield, with only minor variations in the energy and angular distributions of sputtered particles. The success of the density gradient model is attributed to a reduction of the reflection coefficient - leading to increased sputtering yields, similar in effect to surface roughness.

  7. Ultra High Vacuum Sputtering System

    Science.gov (United States)

    1991-07-25

    NO. NO. Washington, D.C. 20332-6448 E.. 1,1. T IT LE (Incirot Securi ty Ciassificalion) (U L t ra High Vacuum Spattering System _1__ 12. PERSONAL...ABSTRACT (Continue on reuerse it necessary and identify by bioc, number) This grant provided for the purchase of an ultra high vacuum sputtering system, for...FOR GRANT FROM DEFENSE UNIVERSITY RESEARCH INSTRUMENTATION PROGRAM Grant no. AFOSR-89-0138 Date Submitted: 27 July, 1991 Title: Ultra High Vacuum Sputtering

  8. Preferential sputtering effects of carbides

    International Nuclear Information System (INIS)

    Taglauer, E.; Varga, P.

    1983-01-01

    Results from sputtering of TaC and TiC by various ions ranging from Xe + to H + are presented. Different effects of preferential sputtering show up in the surface concentration of TaC and TiC due to bombardment with various ions. For TaC mainly mass effects are important whereas binding energy and particularly chemical effects are found in TiC. (G.Q.)

  9. Hydroxyethyl cellulose doped with copper(II) phthalocyanine-tetrasulfonic acid tetrasodium salt as an effective dual functional hole-blocking layer for polymer light-emitting diodes

    Science.gov (United States)

    Wu, Cheng-Liang; Chen, Yun

    2017-07-01

    We report a doping method to improve the performance of solution-processed polymer light-emitting diodes (PLEDs). Doping 12 wt% copper(II) phthalocyanine-tetrasulfonated acid tetrasodium salt (TS-CuPc) into hydroxyethyl cellulose (HEC) as a dual functional hole-blocking layer (df-HBL) of multilayer PLED (glass/ITO/PEDOT:PSS/HY-PPV/TS-CuPc-doped HEC/LiF/Al) significantly enhanced maximum luminance, maximum current and power efficiency over that without the df-HBL (10,319 cd/m2, 2.98 cd/A and 1.24 lm/W) to (29,205 cd/m2, 13.27 cd/A and 9.56 lm/W). CV measurements reveal that HEC possesses a powerful hole-blocking capability. Topography and conductivity AFM images show that doping TS-CuPc increases the interfacial contact area and interfacial conductivity, which can overcome the insulating nature of HEC and thus further facilitate electron injection. Enhancements in device performance are attributed to the improved carrier balance and recombination in the presence of df-HBL, confirmed in electron-only and hole-only devices. Moreover, apparently raised open-circuit voltages provide further evidence that enhanced electron injection is indeed realized by the df-HBL. This study demonstrates an effective approach to develop highly efficient PLEDs.

  10. Amorphous germanium as an electron or hole blocking contact on high-purity germanium detectors

    International Nuclear Information System (INIS)

    Hansen, W.L.; Haller, E.E.

    1976-10-01

    Experiments were performed in an attempt to make thin n + contacts on high-purity germanium by the solid phase/sup 1)/ epitaxial regrowth of arsenic doped amorphous germanium. After cleaning the crystal surface with argon sputtering and trying many combinations of layers, it was not found possible to induce recrystallization below 400 0 C. However, it was found that simple thermally evaporated amorphous Ge made fairly good electron or hole blocking contacts. Excellent spectrometers have been made with amorphous Ge replacing the n + contact. As presently produced, the amorphous Ge contact diodes show a large variation in high-voltage leakage current

  11. Transport theory of sputtering I: Depth of origin of sputtered atoms

    International Nuclear Information System (INIS)

    Zhang, Zhu Lin

    1999-01-01

    Sputter theory employing a sum of two power cross sections has been implemented. Compared with the well known Lindhard power cross section (V∝r -1/m ), a sum of two such cross sections can give a much better approximation to the Born-Mayer scattering in the low energy region (m ∼ 0.1). By using both one and two power cross sections, we have solved the linear transport equations describing the sputtering problem asymptotically. As usual, electronic stopping is ignored in the analysis. It has further been proved that Falcone's theory of the atom ejection process contradicts transport theory. The Andersen-Sigmund relation for partial sputtering yield ratios between two elements in an arbitrary multicomponent target has been derived by both methods. The energy deposited in the target surface layers has been computed for a few typical ion-target combinations. The numerical curves show that both theories generate almost the same results (error m≥0. The former even may be only about one half of the latter as long as m=0

  12. Effect of ring-shaped SiO2 current blocking layer thickness on the external quantum efficiency of high power light-emitting diodes

    Science.gov (United States)

    Zhou, Shengjun; Liu, Mengling; Hu, Hongpo; Gao, Yilin; Liu, Xingtong

    2017-12-01

    A ring-shaped SiO2 CBL underneath the p-electrode was employed to enhance current spreading of GaN-based light-emitting diodes (LEDs). Effects of ring-shaped SiO2 current blocking layer (CBL) thickness on optical and electrical characteristics of high power LEDs were investigated. A 190-nm-thick ring-shaped SiO2 CBL with inclined sidewalls was obtained using a combination of a thermally reflowed photoresist technique and an inductively coupled plasma (ICP) etching process, allowing for the deposition of conformal indium tin oxide (ITO) transparent conductive layer on sidewalls of ring-shaped SiO2 CBL. It was indicated that the external quantum efficiency (EQE) of high power LEDs increased with increasing thickness of ring-shaped SiO2 CBL. The EQE of high power LED with 190-nm-thick ring-shaped SiO2 CBL was 12.7% higher than that of high power LED without SiO2 CBL. Simulations performed with commercial SimuLED software package showed that the ring-shaped SiO2 CBL could significantly alleviate current crowding around p-electrode, resulting in enhanced current spreading over the entire high power LED structure.

  13. Efficient blue-green and green electroluminescent devices obtained by doping iridium complexes into hole-block material as supplementary light-emitting layer

    International Nuclear Information System (INIS)

    Zhou, Liang; Zheng, Youxuan; Deng, Ruiping; Feng, Jing; Song, Mingxing; Hao, Zhaomin; Zhang, Hongjie; Zuo, Jinglin; You, Xiaozeng

    2014-01-01

    In this work, organic electroluminescent (EL) devices with dominant and supplementary light-emitting layers (EMLs) were designed to further improve the EL performances of two iridium III -based phosphorescent complexes, which have been reported to provide EL devices with slow EL efficiency roll-off. The widely used hole-block material 2,2′,2''-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi) was selected as host material to construct the supplementary EML. Compared with single-EML devices, double-EMLs devices showed higher EL efficiencies, higher brightness, and lower operation voltage attributed to wider recombination zone and better balance of carriers. In addition, the insertion of supplementary EML is instrumental in facilitating carriers trapping, thus improving the color purity. Finally, high performance blue-green and green EL devices with maximum current efficiencies of 35.22 and 90.68 cd/A, maximum power efficiencies of 26.36 and 98.18 lm/W, and maximum brightness of 56,678 and 112,352 cd/m 2 , respectively, were obtained by optimizing the doping concentrations. Such a device design strategy extends the application of a double EML device structure and provides a chance to simplify device fabrication processes. -- Highlights: • Electroluminescent devices with supplementary light-emitting layer were fabricated. • Doping concentrations and thicknesses were optimized. • Better balance of holes and electrons causes the enhanced efficiency. • Improved carrier trapping suppresses the emission of host material

  14. Effect of the microstructural characteristics of a Ga-doped TiO2 hole block layer on an inverted structure organic solar cell

    Science.gov (United States)

    Lee, Eun Ju; Ryu, Sang Ouk

    2016-09-01

    Inverted-structure organic solar cells (OSCs) were fabricated using atomic-layer-deposition (ALD) processed Ga-doped TiO2 as hole blocking layer (HBL). Measured photovoltaic efficiencies were greatly related to the crystallinity of the TiO2 films. However, the efficiencies of the OSCs and the crystallinity of the HBL did not show a linear relationship. The HBL was fully crystallized at a deposition temperature of 200 °C or above, and the power conversion efficiency was measured to be 2.7% with for the HBL processed at 200 °C, but the efficiency decreased to 2.4% for the HBL processed at 250 °C. On the other hand, the surface roughness of the crystallized films was found be increased to two fold in the studied temperature range. Once the HBL had been fully crystallized, the major factor that determined the overall performance of OSCs was the surface roughness of the HBL.

  15. The interplay of blocking properties with charge and potential redistribution in thin carbon-doped GaN on n-doped GaN layers

    Science.gov (United States)

    Koller, Christian; Pobegen, Gregor; Ostermaier, Clemens; Huber, Martin; Pogany, Dionyz

    2017-07-01

    In carbon-doped GaN (GaN:C) buffers used in a GaN-on-Si technology, the buffer is embedded in between transition and channel layers. This makes the analysis of buffer properties difficult due to e.g., carrier injection from or potential drop at these adjacent layers. Here, we analyze capacitance- and current-voltage characteristics of 200-300 nm thick GaN:C ([C] = 1019 cm-3) layers which are embedded between a top metal electrode and bottom n-doped GaN (n-GaN). Such structures allow a better potential control in GaN:C and thus determination of the band diagram quantitatively. The accumulation of negative charge (concentration up to 6 × 1017 cm-3) with bias is observed in GaN:C at both polarities. For biases Vappl GaN:C near to its interface with n-GaN so that GaN:C exhibits no potential drop and blocks leakage current. For Vappl > +1.7 V, accumulated negative charges in GaN:C raise an energy barrier of ˜1.1 eV for electron injection from n-GaN to GaN:C. This causes a potential drop in GaN:C leading to a significant leakage current increase. The Fermi level pinning in GaN:C at a commonly referred acceptor at EV + 0.7(±0.2) eV is extracted only from electrostatic considerations. The occupancy change of carbon acceptors is attributed to trapping processes where the dislocation-related conductive paths are supposed to be involved in carrier transport from the top metal electrode to the carbon defect.

  16. Properties of gold nanostructures sputtered on glass

    Directory of Open Access Journals (Sweden)

    Kolská Zdeňka

    2011-01-01

    Full Text Available Abstract We studied the electrical and optical properties, density, and crystalline structure of Au nanostructures prepared by direct current sputtering on glass. We measured temperature dependence of sheet resistance and current-voltage characteristics and also performed scanning electron microscopy [SEM] analysis of gold nanolayers. It was shown that within the wide range of temperatures, gold nanolayers (<10 nm exhibit both metal and semiconducting-like type of conductivity. UV/Vis analysis proved the semiconducting characteristic of intrinsic Au clusters. SEM analysis showed the initiatory stadium of gold layer formation to be running over isolated islands. Gold density calculated from the weight and effective thickness of the layers is an increasing function of the layer thickness up to approximately 100 nm. In thin layers deposited on solid surface, a lattice expansion is observed, which is manifested in the increase of the lattice parameter and the decrease of metal density. With increasing layer thickness, the lattice parameter and the density approach the bulk values.

  17. Memory effects in annealed hybrid gold nanoparticles/block copolymer bilayers

    Science.gov (United States)

    Torrisi, Vanna; Ruffino, Francesco; Licciardello, Antonino; Grazia Grimaldi, Maria; Marletta, Giovanni

    2011-12-01

    We report on the use of the self-organization process of sputtered gold nanoparticles on a self-assembled block copolymer film deposited by horizontal precipitation Langmuir-Blodgett (HP-LB) method. The morphology and the phase-separation of a film of poly- n-butylacrylate- block-polyacrylic acid (P nBuA- b-PAA) were studied at the nanometric scale by using atomic force microscopy (AFM) and Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS). The templating capability of the P nBuA- b-PAA phase-separated film was studied by sputtering gold nanoparticles (NPs), forming a film of nanometric thickness. The effect of the polymer chain mobility onto the organization of gold nanoparticle layer was assessed by heating the obtained hybrid P nBuA- b-PAA/Au NPs bilayer at T > T g. The nanoparticles' distribution onto the different copolymer domains was found strongly affected by the annealing treatment, showing a peculiar memory effect, which modifies the AFM phase response of the Au NPs layer onto the polar domains, without affecting their surfacial composition. The effect is discussed in terms of the peculiar morphological features induced by enhanced mobility of polymer chains on the Au NPs layer.

  18. Memory effects in annealed hybrid gold nanoparticles/block copolymer bilayers

    Directory of Open Access Journals (Sweden)

    Ruffino Francesco

    2011-01-01

    Full Text Available Abstract We report on the use of the self-organization process of sputtered gold nanoparticles on a self-assembled block copolymer film deposited by horizontal precipitation Langmuir-Blodgett (HP-LB method. The morphology and the phase-separation of a film of poly-n-butylacrylate-block-polyacrylic acid (PnBuA-b-PAA were studied at the nanometric scale by using atomic force microscopy (AFM and Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS. The templating capability of the PnBuA-b-PAA phase-separated film was studied by sputtering gold nanoparticles (NPs, forming a film of nanometric thickness. The effect of the polymer chain mobility onto the organization of gold nanoparticle layer was assessed by heating the obtained hybrid PnBuA-b-PAA/Au NPs bilayer at T >Tg. The nanoparticles' distribution onto the different copolymer domains was found strongly affected by the annealing treatment, showing a peculiar memory effect, which modifies the AFM phase response of the Au NPs layer onto the polar domains, without affecting their surfacial composition. The effect is discussed in terms of the peculiar morphological features induced by enhanced mobility of polymer chains on the Au NPs layer.

  19. Effect of Oblique-Angle Sputtered ITO Electrode in MAPbI3 Perovskite Solar Cell Structures

    Science.gov (United States)

    Lee, Kun-Yi; Chen, Lung-Chien; Wu, Yu-June

    2017-10-01

    This investigation reports on the characteristics of MAPbI3 perovskite films on obliquely sputtered ITO/glass substrates that are fabricated with various sputtering times and sputtering angles. The grain size of a MAPbI3 perovskite film increases with the oblique sputtering angle of ITO thin films from 0° to 80°, indicating that the surface properties of the ITO affect the wettability of the PEDOT:PSS thin film and thereby dominates the number of perovskite nucleation sites. The optimal power conversion efficiency (Eff) is achieved 11.3% in a cell with an oblique ITO layer that was prepared using a sputtering angle of 30° for a sputtering time of 15 min.

  20. Organic field-effect transistor nonvolatile memories utilizing sputtered C nanoparticles as nano-floating-gate

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jie; Liu, Chang-Hai; She, Xiao-Jian; Sun, Qi-Jun; Gao, Xu; Wang, Sui-Dong, E-mail: wangsd@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123 (China)

    2014-10-20

    High-performance organic field-effect transistor nonvolatile memories have been achieved using sputtered C nanoparticles as the nano-floating-gate. The sputtered C nano-floating-gate is prepared with low-cost material and simple process, forming uniform and discrete charge trapping sites covered by a smooth and complete polystyrene layer. The devices show large memory window, excellent retention capability, and programming/reading/erasing/reading endurance. The sputtered C nano-floating-gate can effectively trap both holes and electrons, and it is demonstrated to be suitable for not only p-type but also n-type organic field-effect transistor nonvolatile memories.

  1. Charge-state related effects in sputtering of LiF by swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Assmann, W. [Ludwig-Maximilians-Universität München, 85748 Garching (Germany); Ban-d' Etat, B. [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Bender, M. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Boduch, P. [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Grande, P.L. [Univ. Fed. Rio Grande do Sul, BR-91501970 Porto Alegre, RS (Brazil); Lebius, H.; Lelièvre, D. [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Marmitt, G.G. [Univ. Fed. Rio Grande do Sul, BR-91501970 Porto Alegre, RS (Brazil); Rothard, H. [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Seidl, T.; Severin, D.; Voss, K.-O. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Toulemonde, M., E-mail: toulemonde@ganil.fr [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Trautmann, C. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Technische Universität Darmstadt, 64289 Darmstadt (Germany)

    2017-02-01

    Sputtering experiments with swift heavy ions in the electronic energy loss regime were performed by using the catcher technique in combination with elastic recoil detection analysis. The angular distribution of particles sputtered from the surface of LiF single crystals is composed of a jet-like peak superimposed on a broad isotropic distribution. By using incident ions of fixed energy but different charges states, the influence of the electronic energy loss on both components is probed. We find indications that isotropic sputtering originates from near-surface layers, whereas the jet component may be affected by contributions from depth up to about 150 nm.

  2. Organic field-effect transistor nonvolatile memories utilizing sputtered C nanoparticles as nano-floating-gate

    International Nuclear Information System (INIS)

    Liu, Jie; Liu, Chang-Hai; She, Xiao-Jian; Sun, Qi-Jun; Gao, Xu; Wang, Sui-Dong

    2014-01-01

    High-performance organic field-effect transistor nonvolatile memories have been achieved using sputtered C nanoparticles as the nano-floating-gate. The sputtered C nano-floating-gate is prepared with low-cost material and simple process, forming uniform and discrete charge trapping sites covered by a smooth and complete polystyrene layer. The devices show large memory window, excellent retention capability, and programming/reading/erasing/reading endurance. The sputtered C nano-floating-gate can effectively trap both holes and electrons, and it is demonstrated to be suitable for not only p-type but also n-type organic field-effect transistor nonvolatile memories.

  3. Thermal conductivities of thin, sputtered optical films

    International Nuclear Information System (INIS)

    Henager, C.H. Jr.; Pawlewicz, W.T.

    1991-05-01

    The normal component of the thin film thermal conductivity has been measured for the first time for several advanced sputtered optical materials. Included are data for single layers of boron nitride (BN), aluminum nitride (AIN), silicon aluminum nitride (Si-Al-N), silicon aluminum oxynitride (Si-Al-O-N), silicon carbide (SiC), and for dielectric-enhanced metal reflectors of the form Al(SiO 2 /Si 3 N 4 ) n and Al(Al 2 O 3 /AIN) n . Sputtered films of more conventional materials like SiO 2 , Al 2 O 3 , Ta 2 O 5 , Ti, and Si have also been measured. The data show that thin film thermal conductivities are typically 10 to 100 times lower than conductivities for the same materials in bulk form. Structural disorder in the amorphous or very fine-grained films appears to account for most of the conductivity difference. Conclusive evidence for a film/substrate interface contribution is presented

  4. Laser sputter neutral mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    King, B.V.; Clarke, M.; Hu, H.; Betz [Newcastle Univ., NSW (Australia). Dept. of Physics

    1993-12-31

    Laser sputter neutral mass spectrometry (LSNMS) is an emerging technique for highly sensitive surface analysis. In this technique a target is bombarded with a pulsed beam of keV ions. The sputtered particles are intercepted by a high intensity pulsed laser beam above the surface and ionised with almost 100% efficiency. The photions may then be mass analysed using a quadrupole or, more commonly, using time of flight (TOF) techniques. In this method photoions are extracted from the ionisation region, accelerated to a known energy E{sub o} and strike a channelplate detector a distance `d` away. The flight time `t` of the photoions is then related to their mass by `d` {radical}m / {radical} 2E{sub o} so measurement of `t` allows mass spectra to be obtained. It is found that LSNMS is an emerging technique of great sensitivity and flexibility, useful for both applied analysis and to investigate basic sputtering processes. 4 refs., 3 figs.

  5. Faraday screen sputtering on TPX

    International Nuclear Information System (INIS)

    Ehst, D.A.

    1994-12-01

    The TPX design stipulates that the ion-cyclotron resonance frequency (ICRF) antenna must have a Faraday screen (FS). The author considers here possible low Z coatings for the screen, as well as sputtering behavior of the Ni and Ti substrates. The theory of rf-induced sputtering has been developed, and he follows those theoretical approaches. The author's emphasis will be on both impurity generation as a possible source of increased Z eff , and also on actual erosion-lifetime of the materials under worst case conditions

  6. Improving the performance of AlGaN-based deep-ultraviolet light-emitting diodes using electron blocking layer with a heart-shaped graded Al composition

    Science.gov (United States)

    Kwon, M. R.; Park, T. H.; Lee, T. H.; Lee, B. R.; Kim, T. G.

    2018-04-01

    We propose a design for highly efficient AlGaN-based deep-ultraviolet light-emitting diodes (DUV LEDs) using a heart-shaped graded Al composition electron-blocking layer (EBL). This novel structure reduced downward band bending at the interface between the last quantum barrier and the EBL and flattened the electrostatic field in the interlayer between the barriers of the multi-quantum barrier EBL. Consequently, electron leakage was significantly suppressed and hole injection efficiency was found to have improved. The parameter values of simulation were extracted from the experimental data of the reference DUV LEDs. Using the SimuLED, we compared the electrical and optical properties of three structures with different Al compositions in the active region and the EBL. The internal quantum efficiency of the proposed structure was shown to exceed those of the reference DUV LEDs by a factor of 1.9. Additionally, the output power at 20 mA was found to increase by a factor of 2.1.

  7. Obliquely sputtered Co/Cr thin film tape for bidirectional recording

    NARCIS (Netherlands)

    Nguyen, L.T.; Lisfi, A.; Lodder, J.C.

    2003-01-01

    We report the growth and properties of a thin film tape, which can be equivalently recorded in both directions. The experimental tape consists of a 20 nm thick Co layer grown on top of a Cr underlayer 120 nm. The two layers were consecutively sputtered at incident angle of 70° at room temperature

  8. Sputtering technology in solid film lubrication

    Science.gov (United States)

    Spalvins, T.

    1978-01-01

    Potential and present sputtering technology is discussed as it applies to the deposition of solid film lubricants particularly MoS2, WS2, and PTFE. Since the sputtered films are very thin, the selection of the sputtering parameters and substrate condition is very critical as reflected by the lubricating properties. It was shown with sputtered MoS2 films that the lubricating characteristics are directly affected by the selected sputtering parameters (power density, pressure, sputter etching, dc-biasing, etc.) and the substrate temperature, chemistry, topography and the environmental conditions during the friction tests. Electron microscopy and other surface sensitive analytical techniques illustrate the resulting changes in sputtered MoS2 film morphology and chemistry which directly influence the film adherence and frictional properties.

  9. Growth of cerium oxide thin layers for the manufacture of dosemeters and/or irradiation detectors by magnetron RF cathodic sputtering; Croissance de couches minces d'oxyde de cerium pour la realisation de dosimetres et/ou de detecteurs d'irradiation par pulverisation cathodique RF magnetron

    Energy Technology Data Exchange (ETDEWEB)

    Ta, M.T.; Briand, D.; Guhel, Y.; Bernard, J.; Boudart, B. [Laboratoire Universitaire des Sciences Appliquees de Cherbourg (LUSAC), 50 - Cherbourg (France)

    2007-07-01

    Oxide thin films deposited on silicon substrate are interesting for the manufacture of dosemeters and detectors of gas, humidity, temperature and irradiation. The irradiation dose measurement is required for assessing the risks and advantages of the use of ionizing radiations in fields such as biology, medicine and more generally in all the civil and military nuclear applications. According to literature, cerium oxide seems to be potentially interesting for the manufacture of dosemeters and/or irradiation detectors. The influence of the deposition parameters, such as the inter-electrodes distance, the temperature, the RF power, the work pressure, on the crystalline quality of the CeO{sub 2} layers deposited on a silicon (111) substrate by magnetron RF cathodic sputtering has been studied. All these thin films have been characterized by X-ray diffraction and by Raman spectroscopy. At the present time, studies are carried out on 'flash' annealing in order to improve the crystalline state of the thin layers. The aim is to study the influence of gamma and neutrons irradiations on the electric properties of capacities made of CeO{sub 2} thin films. (O.M.)

  10. Fuzzy tungsten in a magnetron sputtering device

    Energy Technology Data Exchange (ETDEWEB)

    Petty, T.J., E-mail: tjpetty@liv.ac.uk [Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ (United Kingdom); Khan, A. [Pariser Building-G11, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, M13 9PL (United Kingdom); Heil, T. [NiCaL, Block C Waterhouse Building, 1-3 Brownlow Street, Liverpool, L69 3GL (United Kingdom); Bradley, J.W., E-mail: j.w.bradley@liverpool.ac.uk [Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ (United Kingdom)

    2016-11-15

    Helium ion induced tungsten nanostructure (tungsten fuzz) has been studied in a magnetron sputtering device. Three parameters were varied, the fluence from 3.4 × 10{sup 23}–3.0 × 10{sup 24} m{sup −2}, the He ion energy from 25 to 70 eV, and the surface temperature from 900 to 1200 K. For each sample, SEM images were captured, and measurements of the fuzz layer thickness, surface roughness, reflectivity, and average structure widths are provided. A cross-over point from pre-fuzz to fully formed fuzz is found at 2.4 ± 0.4 × 10{sup 24} m{sup −2}, and a temperature of 1080 ± 60 K. No significant change was observed in the energy sweep. The fuzz is compared to low fluence fuzz created in the PISCES-A linear plasma device. Magnetron fuzz is less uniform than fuzz created by PISCES-A and with generally larger structure widths. The thicknesses of the magnetron samples follow the original Φ{sup 1/2} relation as opposed to the incubation fluence fit. - Highlights: • Fuzz has been created in a magnetron sputtering device. • Three parameters for fuzz formation have been swept. • A cross-over from pre-fuzz to fully formed fuzz is seen. • Evidence for annealing out at lower temperatures than has been seen before. • Evidence to suggest that fuzz grown in discrete exposures is not consistent with fuzz grown in one long exposure.

  11. Fuzzy tungsten in a magnetron sputtering device

    International Nuclear Information System (INIS)

    Petty, T.J.; Khan, A.; Heil, T.; Bradley, J.W.

    2016-01-01

    Helium ion induced tungsten nanostructure (tungsten fuzz) has been studied in a magnetron sputtering device. Three parameters were varied, the fluence from 3.4 × 10 23 –3.0 × 10 24  m −2 , the He ion energy from 25 to 70 eV, and the surface temperature from 900 to 1200 K. For each sample, SEM images were captured, and measurements of the fuzz layer thickness, surface roughness, reflectivity, and average structure widths are provided. A cross-over point from pre-fuzz to fully formed fuzz is found at 2.4 ± 0.4 × 10 24  m −2 , and a temperature of 1080 ± 60 K. No significant change was observed in the energy sweep. The fuzz is compared to low fluence fuzz created in the PISCES-A linear plasma device. Magnetron fuzz is less uniform than fuzz created by PISCES-A and with generally larger structure widths. The thicknesses of the magnetron samples follow the original Φ 1/2 relation as opposed to the incubation fluence fit. - Highlights: • Fuzz has been created in a magnetron sputtering device. • Three parameters for fuzz formation have been swept. • A cross-over from pre-fuzz to fully formed fuzz is seen. • Evidence for annealing out at lower temperatures than has been seen before. • Evidence to suggest that fuzz grown in discrete exposures is not consistent with fuzz grown in one long exposure.

  12. Grafting of Gold Nanoparticles on Glass Using Sputtered Gold Interlayers

    Directory of Open Access Journals (Sweden)

    Ondřej Kvítek

    2014-01-01

    Full Text Available Three-step preparation of nanostructured Au layer on glass substrate is described. The procedure starts with sputtered gold interlayer, followed by grafting with dithiols and final coverage with gold nanoparticles (AuNPs. Successful binding of dithiols on the sputtered Au film was confirmed by X-ray photoelectron spectroscopy measurement. AuNPs bound to the surface were observed using atomic force microscopy. Both single nanoparticles and their aggregates were observed. UV-Vis spectra show broadening of surface plasmon resonance peak after AuNPs binding caused by aggregation of AuNPs on the sample surface. Zeta potential measurements suggest that a large part of the dithiol molecules are preferentially bound to the gold interlayer via both –SH groups.

  13. Target surface condition during reactive glow discharge sputtering of copper

    International Nuclear Information System (INIS)

    Depla, D; Haemers, J; Gryse, R De

    2002-01-01

    During reactive glow discharge sputtering of copper in an argon/nitrogen plasma, we noticed an abrupt change of the target voltage and the deposition rate when the nitrogen concentration in the plasma exceeds a critical value. To explain this behaviour, the target surface after reactive glow discharge sputtering was examined by x-ray photoelectron spectroscopy (XPS). An experimental arrangement was constructed that allows direct transfer of the glow discharge cathode to the XPS analysis chamber without air exposure. These XPS measurements revealed that several different chemical states of nitrogen are present in the layer that forms on the target surface. The relative concentration of these different states changes when the critical nitrogen concentration in the plasma is exceeded

  14. Applying RF Magnetron sputtering to prepare ZnO thin films and their characterization

    International Nuclear Information System (INIS)

    Saad, M.; Kassis, A.

    2009-05-01

    ZnO thin films were prepared using Rf magnetron sputtering under several preparation conditions (different values of deposition pressure, Rf power, substrate temperature). The optical properties of these films were investigated by measuring their transmission in the spectral range (300-1000 nm), and the electrical properties were investigated by measuring their electrical resistance. Results have been discussed in terms of the modified Thornton model for sputtered thin metal oxide films. Preparation conditions for depositing the highly resistive transparent i-ZnO buffer layer and the highly conducting transparent n-ZnO window layer for solar cells were proposed. (author)

  15. Simulation experiments and solar wind sputtering

    International Nuclear Information System (INIS)

    Griffith, J.E.; Papanastassiou, D.A.; Russell, W.A.; Tombrello, T.A.; Weller, R.A.

    1978-01-01

    In order to isolate the role played by solar wind sputtering from other lunar surface phenomena a number of simulation experiments were performed, including isotope abundance measurements of Ca sputtered from terrestrial fluorite and plagioclase by 50-keV and 130-keV 14 N beams, measurement of the energy distribution of U atoms sputtered with 80-keV 40 Ar, and measurement of the fraction of sputtered U atoms which stick on the surfaces used to collect these atoms. 10 references

  16. Electrical Properties of Ultra-thin TiO2 Compact Layer on FTO for Perovskite Solar cells

    Science.gov (United States)

    Songtanasit, R.; Taychatanapat, T.; Chatraphorn, S.

    2017-09-01

    A TiO2 compact layer or blocking layer plays a crucial role in a hybrid organic-inorganic lead halide perovskite solar cell because it can prevent the carrier recombination at the interface of fluorine-doped tin oxide (FTO) and perovskite layers. There are several methods to fabricate this layer such as spray pyrolysis or spin-coating which is solution-based synthesis that is difficult to avoid pinholes in the surface of the blocking layer. In this work, TiO2 blocking layers are fabricated by radio-frequency (RF) magnetron sputtering using Ti metallic target with O2 partial pressure in Ar atmosphere on FTO coated glasses. The controlled parameters for the deposition of TiO2 compact layer are RF power, O2 partial pressure, and deposition time. The optimization of the TiO2 compact layers are found from the diode I-V characteristics between the TiO2/FTO interfaces. The resistance between the TiO2/FTO interfaces deviates from an ohmic contact towards a diode behavior when the thickness of TiO2 is increased. The thickness of the films is directly measured by surface profilometer. In addition, the UV-VIS-NIR spectroscopy is used to observe the optical transmission of the films.

  17. Magnetron Sputtered Molybdenum Oxide for Application in Polymers Solar Cells

    Science.gov (United States)

    Sendova-Vassileva, M.; Dikov, Hr; Vitanov, P.; Popkirov, G.; Gergova, R.; Grancharov, G.; Gancheva, V.

    2016-10-01

    Thin films of molybdenum oxide were deposited by radio frequency (RF) magnetron sputtering in Ar from a MoO3 target at different deposition power on glass and silicon substrates. The thickness of the films was determined by profilometer measurements and by ellipsometry. The films were annealed in air at temperatures between 200 and 400°C in air. The optical transmission and reflection spectra were measured. The conductivity of the as deposited and annealed films was determined. The crystal structure was probed by Raman spectroscopy. The oxidation state of the surface was studied by X-ray photoelectron spectroscopy (XPS) spectroscopy. The deposition technique described above was used to experiment with MoOx as a hole transport layer (HTL) in polymer solar cells with bulk hetrojunction active layer, deposited by spin coating. The performance of these layers was compared with poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), which is the standard material used in this role. The measured current-voltage characteristics of solar cells with the structure glass/ITO/HTL/Poly(3-hexyl)thiophene (P3HT):[6,6]-phenyl-C61- butyric acid methyl ester (PCBM)/Al demonstrate that the studied MoOx layer is a good HTL and leads to comparable characteristics to those with PEDOT:PSS. On the other hand the deposition by magnetron sputtering guarantees reliable and repeatable HTLs.

  18. Effect of argon ion sputtering of surface on hydrogen permeation through vanadium

    International Nuclear Information System (INIS)

    Yamawaki, Michio; Namba, Takashi; Yoneoka, Toshiaki; Kanno, Masayoshi; Shida, Koji.

    1983-01-01

    In order to measure the hydrogen permeation rate through V with atomically cleaned surface, an Ar ion sputtering apparatus has been installed in the hydrogen permeability measuring system. The permeation rate of the initial specimen was found to be increased by about one order of magnitude after Ar ion sputtering of its upstream side surface. Repeating of such a sputter-cleaning was not so much effective in increasing the steady state permeation rate as the initial sputtering was, but it accelerated the transient response rate by a factor of 2 or 3. The transient response rate was also accelerated by the increase of hydrogen pressure, but this effect tended to be diminished by the sputter-cleaning of specimen surface. The surface impurity layer on the downstream side of specimen was also inferred to act as a diffusion barrier affecting the steady state permeation rate. The present value of activation energy for hydrogen permeation through V at temperatures below 873K was the smallest one ever obtained, showing that the surface effect was minimized in the present study on account of the surface sputter-cleaning in addition to the ultra high vacuum system. (author)

  19. Measurements of beryllium sputtering yields at JET

    Science.gov (United States)

    Jet-Efda Contributors Stamp, M. F.; Krieger, K.; Brezinsek, S.

    2011-08-01

    The lifetime of the beryllium first wall in ITER will depend on erosion and redeposition processes. The physical sputtering yields for beryllium (both deuterium on beryllium (Be) and Be on Be) are of crucial importance since they drive the erosion process. Literature values of experimental sputtering yields show an order of magnitude variation so predictive modelling of ITER wall lifetimes has large uncertainty. We have reviewed the old beryllium yield experiments on JET and used current beryllium atomic data to produce revised beryllium sputtering yields. These experimental measurements have been compared with a simple physical sputtering model based on TRIM.SP beryllium yield data. Fair agreement is seen for beryllium yields from a clean beryllium limiter. However the yield on a beryllium divertor tile (with C/Be co-deposits) shows poor agreement at low electron temperatures indicating that the effect of the higher sputtering threshold for beryllium carbide is important.

  20. Characterization and properties Ti-Al-Si-N nanocomposite coatings prepared by middle frequency magnetron sputtering

    Science.gov (United States)

    Zou, C. W.; Zhang, J.; Xie, W.; Shao, L. X.; Guo, L. P.; Fu, D. J.

    2011-10-01

    TiN-containing amorphous Ti-Al-Si-N (nc-TiN/a-Si 3N 4 or a-AlN) nanocomposite coatings were deposited by using a modified closed field twin unbalanced magnetron sputtering system which is arc assisted and consists of two circles of targets, at a substrate temperature of 300 °C. XRD, XPS and High-resolution TEM experiments showed that the coatings contain TiN nanocrystals embedded in the amorphous Si 3N 4 or AlN matrix. The coatings exhibit good mechanical properties that are greatly influenced by the Si contents. The hardness of the Ti-Al-Si-N coatings deposited at Si targets currents of 5, 8, 10, and 12 A were 45, 47, 54 and 46 GPa, respectively. The high hardness of the deposited Ti-Al-Si-N coatings may be own to the plastic distortion and dislocation blocking by the nanocrystalline structure. On the other hand, the friction coefficient decreases monotonously with increasing Si contents. This result would be caused by tribo-chemical reactions, which often take place in many ceramics, e.g. Si 3N 4 reacts with H 2O to produce SiO 2 or Si(OH) 2 tribolay-layer.

  1. Effect of sputtering power on structural and optical properties of radio frequency-sputtered In2S3 thin films.

    Science.gov (United States)

    Hwang, Dong Hyun; Cho, Shinho; Hui, Kwun Nam; Son, Young Guk

    2014-12-01

    In this study, we investigated the structural and optical properties of indium sulfide (In2S3) thin films as a substitute for the CdS buffer layer in Cu(In,Ga)Se2 (CIGS) solar cells. The In2S3 films were deposited on glass substrates using radio frequency (RF) magnetron sputtering. The sputtering power was changed from 60 to 120 W in 20 W increments. The effects of sputtering power on the crystallinity, surface morphology, and optical properties of the films were characterized with X-ray diffraction (XRD), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDS), and UV-visible spectrophotometry. The XRD analyses indicated that the films were polycrystalline β-In2S3 structures with two preferred orientations along the (103) and (206) directions. The AFM images revealed that the films had nanosized grains and that the size increased from 7 nm for the samples prepared at 60 W to 13 nm for those prepared at 120 W. The optical band gap of the samples was found to vary between 2.88 and 2.43 eV.

  2. Magnetron sputtered gadolinia-doped ceria diffusion barriers for metal-supported solid oxide fuel cells

    DEFF Research Database (Denmark)

    Sønderby, Steffen; Klemensø, Trine; Christensen, Bjarke H.

    2014-01-01

    Gadolinia-doped ceria (GDC) thin films are deposited by reactive magnetron sputtering in an industrial-scale setup and implemented as barrier layers between the cathode and electrolyte in metal-based solid oxide fuel cells consisting of a metal support, an electrolyte of ZrO2 co-doped with Sc2O3 ...

  3. Characterization of Niobium Oxide Films Deposited by High Target Utilization Sputter Sources

    International Nuclear Information System (INIS)

    Chow, R; Ellis, A D; Loomis, G E; Rana, S I

    2007-01-01

    High quality, refractory metal, oxide coatings are required in a variety of applications such as laser optics, micro-electronic insulating layers, nano-device structures, electro-optic multilayers, sensors and corrosion barriers. A common oxide deposition technique is reactive sputtering because the kinetic mechanism vaporizes almost any solid material in vacuum. Also, the sputtered molecules have higher energies than those generated from thermal evaporation, and so the condensates are smoother and denser than those from thermally-evaporated films. In the typical sputtering system, target erosion is a factor that drives machine availability. In some situations such as nano-layered capacitors, where the device's performance characteristics depends on thick layers, target life becomes a limiting factor on the maximizing device functionality. The keen interest to increase target utilization in sputtering has been addressed in a variety of ways such as target geometry, rotating magnets, and/or shaped magnet arrays. Also, a recent sputtering system has been developed that generates a high density plasma, directs the plasma beam towards the target in a uniform fashion, and erodes the target in a uniform fashion. The purpose of this paper is to characterize and compare niobia films deposited by two types of high target utilization sputtering sources, a rotating magnetron and a high density plasma source. The oxide of interest in this study is niobia because of its high refractive index. The quality of the niobia films were characterized spectroscopically in optical transmission, ellipsometrically, and chemical stoichiometry with X-ray photo-electron spectroscopy. The refractive index, extinction coefficients, Cauchy constants were derived from the ellipsometric modeling. The mechanical properties of coating density and stress are also determined

  4. In-situ TEM investigation of microstructural evolution in magnetron sputtered Al-Zr and Al-Zr-Si coatings during heat treatment

    DEFF Research Database (Denmark)

    Gudla, Visweswara Chakravarthy; Rechendorff, Kristian; Balogh, Zoltan Imre

    2016-01-01

    The magnetron sputtered Al–Zr and Al–Zr–Si coatings were heat treated in-situ in a transmission electron microscope as well as ex-situ to observe their annealing behaviour and phase transformations. The samples were heated up to a temperature of 550 °C and then cooled to room temperature. A layered...... structure with alternating layers of Al and Zr/Si rich Al was found for the as deposited sputter coatings. During in-situ heat treatment, the phases formed in the coatings were analysed using selective area electron diffraction and energy dispersive Xrayspectroscopy. For the Al–Zr sputtered coatings...

  5. Nanoporous Ti-metal film deposition using radio frequency magnetron sputtering technique for photovoltaic application.

    Science.gov (United States)

    Sung, Youl-Moon; Paeng, Sung-Hwan; Moon, Byung-Ho; Kwak, Dong-Joo

    2012-02-01

    Nanoporous Ti-metal film electrode was fabricated by radio frequency (rf) magnetron sputtering technique on nanoporous TiO2 layer prepared by sol-gel combustion method and investigated with respect to its photo-anode properties of TCO-less DSCs. The porous Ti layer (approximately 1 microm) with low sheet resistance (approximately 17 Omega/sq.) can collect electrons from the TiO2 layer and allows the ionic diffusion of I(-)/I(3-) through the hole. The porous Ti layer with highly ordered columnar structure prepared by 8 mTorr sputtering shows the good impedance characteristics. The efficiency of prepared TCO-less DSCs sample is about 4.83% (ff: 0.6, Voc: 0.65 V, Jsc: 11.2 mA/cm2).

  6. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  7. Development of model CJ-500 coater using magnetron sputter and arc

    International Nuclear Information System (INIS)

    Zeng Hongyin

    1999-12-01

    The Model CJ-500 coater and its technology characteristics and technical parameters as well as finished work piece cases are introduced. By changing magnetic system, it has been achieved that the coating method changes from the magnetron sputtering to arc or from arc to magnetron sputtering in a coater. It is also convenient to change the electric apparatus connection wires. Some satisfactory Ti film and TiN film are deposited, which has good adhesive power and uniform film layer. The deposition rate both Ti and TiN film exceeds 50 nm/min. In addition, the coater can be used in plasma etching and in new material development of nuclear industry

  8. Pulsed DC magnetron sputtered piezoelectric thin film aluminum nitride – Technology and piezoelectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Stoeckel, C., E-mail: chris.stoeckel@zfm.tu-chemnitz.de; Kaufmann, C.; Hahn, R.; Schulze, R. [Center for Microtechnologies, Chemnitz University of Technology, Chemnitz 09126 (Germany); Billep, D. [Fraunhofer Institute for Electronic Nano Systems (ENAS), Chemnitz 09126 (Germany); Gessner, T. [Center for Microtechnologies, Chemnitz University of Technology, Chemnitz 09126 (Germany); Fraunhofer Institute for Electronic Nano Systems (ENAS), Chemnitz 09126 (Germany)

    2014-07-21

    Pulsed DC magnetron sputtered aluminum nitride (AlN) thin films are prepared on several seed layers and at different sputtering conditions. The piezoelectric c-axis (002) orientation of the AlN is analyzed with X-ray diffraction method. The transverse piezoelectric coefficient d{sub 31} is determined with a Laser-Doppler-Vibrometer at cantilevers and membranes by analytical calculations and finite element method. Additionally, thin film AlN on bulk silicon is used to characterize the longitudinal piezoelectric charge coefficient d{sub 33}.

  9. Sputtering ultra-small Pt on nanographitic flakes deposited by electrophoresis for ethanol electro oxidation

    Science.gov (United States)

    Daryakenari, Ahmad Ahmadi; Daryakenari, Mohammad Ahmadi; Omidvar, Hamid

    2018-01-01

    To acquire highly efficient and cost-effective fuel cells, numerous research works have been carried out to the development low cost and excellent performance of electrocatalysts. In this paper, a solution-based electrophoretic deposition (EPD) technique for fabrication of Pt-based catalyst layers is studied. Nanographitic flake coatings used as catalyst support for sputtered platinium (Pt) were fabricated via the electrophoretic deposition (EPD) of dispersed nanographitic flakes in isopropyl alcohol. Magnesium nitrate hexahydrate (MNH) was used as an additive binder in the EPD process. Subsequently, the platinium particles were deposited by a direct sputtering on the fabricated nanographitic flake coatings.

  10. Implantation, recoil implantation, and sputtering

    International Nuclear Information System (INIS)

    Kelly, R.

    1984-01-01

    Underlying ion-beam modification of surfaces is the more basic subject of particle-surface interaction. The ideas can be grouped into forward and backward features, i.e. those affecting the interior of the target and those leading to particle expulsion. Forward effects include the stopping of the incident particles and the deposition of energy, both governed by integral equations which are easily set up but difficult to solve. Closely related is recoil implantation where emphasis is placed not on the stopping of the incident particles but on their interaction with target atoms with resulting implantation of these atoms. Backward effects, all of which are denoted as sputtering, are in general either of collisional, thermal, electronic, or exfoliational origin. (Auth.)

  11. Lithium insertion in sputtered vanadium oxide film

    DEFF Research Database (Denmark)

    West, K.; Zachau-Christiansen, B.; Skaarup, S.V.

    1992-01-01

    Vanadium oxide films have been prepared by RF-sputtering using an oxygen containing sputter ps and a V2O5 target. The main component of these films is orthorhombic V2O5 with poor crystallinity and a tendency for ordering of the crystallites with the c-direction parallel to the substrate. All films...... were oxygen deficient compared to V2O5. Films prepared in pure argon were reduced to V(4) or lower. The vanadium oxide films were tested in solid-state lithium cells. Films sputtered in oxygen showed electrochemical properties similar to crystalline V2O5. The main differences are a decreased capacity...

  12. Sensitivity and stability of sputtered sandwich photocells

    International Nuclear Information System (INIS)

    Murray, H.; Piel, A.

    1979-01-01

    The physical parameters of sputtered Metal-Semiconductor-Metal photocells are described in view of solar energy conversion. Specific properties of sputtered films lead to a particular stability of physical parameters such as dark conduction, capacitance and dielectric losses. Interband transitions occur when the photon energy is larger than the bandgap of the photoconductor. The transport of photo-excited carriers in the built-in electric field involves the existence of a photovoltaic effect. The influence of sputtering on the specific properties of solar energy conversion is discussed. (author)

  13. Chemical sputtering by impact of excited molecules

    International Nuclear Information System (INIS)

    Krstic, P.S.; Reinhold, C.O.; Stuart, S.J.

    2007-01-01

    We study chemical sputtering of deuterated amorphous carbon surfaces by D atoms, vibrationally excited D 2 , and dissociating D 3 molecules, in a range of impact energies, 7.5 - 30 eV/D. We analyze the role of the internal state, i.e. the vibrationally excited and dissociating states of the neutral molecules resulting from above-surface neutralization of impacting molecular ions in typical sputtering experiments. The sputtering yields are shown to considerably increase with the internal vibrational energy at the lowest impact energies. By comparison of calculated and measured yields we draw conclusions regarding the possible mechanisms for neutralization. (authors)

  14. Semi-automatic spray pyrolysis deposition of thin, transparent, titania films as blocking layers for dye-sensitized and perovskite solar cells

    Czech Academy of Sciences Publication Activity Database

    Krýsová, Hana; Krýsa, J.; Kavan, Ladislav

    2018-01-01

    Roč. 9, APR 2018 (2018), s. 1135-1145 ISSN 2190-4286 R&D Projects: GA ČR GA17-20008S; GA ČR(CZ) GA18-08959s Institutional support: RVO:61388955 Keywords : blocking films * FTO * solar cells Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) Impact factor: 3.127, year: 2016

  15. Comparative study of ITO and TiN fabricated by low-temperature RF biased sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Daniel K., E-mail: daniel.simon@namlab.com; Schenk, Tony; Dirnstorfer, Ingo; Fengler, Franz P. G.; Jordan, Paul M.; Krause, Andreas [NaMLab gGmbH, Nöthnitzerstr. 64, 01187 Dresden (Germany); Tröger, David [Westsächsische Hochschule Zwickau, Fachgruppe Nanotechnologie, Dr.-Friedrichs-Ring 2a, 08056 Zwickau (Germany); Mikolajick, Thomas [NaMLab gGmbH, Nöthnitzerstr. 64, 01187 Dresden, Germany and TU Dresden, Institut für Halbleiter- und Mikrosystemtechnik (IHM), 01062 Dresden (Germany)

    2016-03-15

    Radio frequency (RF) biasing induced by a second plasma source at the substrate is applied to low-temperature sputtering processes for indium tin oxide (ITO) and titanium nitride (TiN) thin films. Investigations on crystal structure and surface morphology show that RF-biased substrate plasma processes result in a changed growth regime with different grain sizes and orientations than those produced by processes without a substrate bias. The influence of the RF bias is shown comparatively for reactive RF-sputtered ITO and reactive direct-current-sputtered TiN. The ITO layers exhibit an improved electrical resistivity of 0.5 mΩ cm and an optical absorption coefficient of 0.5 × 10{sup 4 }cm{sup −1} without substrate heating. Room-temperature sputtered TiN layers are deposited that possess a resistivity (0.1 mΩ cm) of 3 orders of magnitude lower than, and a density (5.4 g/cm{sup 3}) up to 45% greater than, those obtained from layers grown using the standard process without a substrate plasma.

  16. Growth of TiO2 thin films on chemically textured Si for solar cell applications as a hole-blocking and antireflection layer

    Science.gov (United States)

    Singh, Ranveer; Kumar, Mohit; Saini, Mahesh; Singh, Avanendra; Satpati, Biswarup; Som, Tapobrata

    2017-10-01

    In this work, we investigate the broad-band photoabsorption of an n-TiO2 thin film and its hole-blocking properties when a heterostructure is grown on a chemically textured p-Si substrate. We demonstrate that average specular reflectance of conformally grown TiO2 thin films on chemically prepared pyramidally textured Si substrates can be brought down to ∼0.2% (in the wavelength range of 300-1200 nm), which increases up to ∼0.53% after annealing at 673 K in air for 1 h. X-ray diffraction data reveal the amorphous nature of as-grown TiO2 thin films which undergoes a transition to a crystalline one after annealing. In addition, bulk current-voltage characteristics show that the leakage current increases after annealing which corroborates well a with change in the band gap, as is measured from the optical absorption spectra, due to a transition from amorphous to crystalline (anatase phase) of TiO2. Moreover, TiO2/Si heterojunction allows the transport of electrons but blocks the transport of holes. The present results are not only important for the fundamental understanding of the charge transport across TiO2/Si heterostructures but also to design hole-blocking solar cells.

  17. Magnetic nanostructures formation via local anodic oxidation and magnetron sputtering through lithographic mask

    Directory of Open Access Journals (Sweden)

    Lenka Pravdova

    2016-10-01

    Full Text Available Changes of magnetic properties of thin metallic films caused by the magnetron sputtering technique and by oxidation lithography were studied. The magnetic nanostructure formation was done via a lithography by sputtering the material through a mask. The anodic oxidation lithography (LAO via scanning probe microscopy (SPM device Ntegra Aura was used to attempt to create the magnetic nanostructures. At the beginning, the work has been scoped to the preparation and testing multilayered magnetic nanostructures based on different combinations in material composition of layers. The magnetic properties of these samples were examined by Kerr phenomenon. We observed increasing of the magnetic hardness of the magnetic nanostructure when the copper layer in the composition of ferromagnetic and antiferromagnetic multilayers has been replaced by an aluminium layer. Adding the aluminium layer onto the copper layer resulted in a decrease of magnetic hardness. This work was followed by creating of horizontal nanostructures by LAO. Changes induced by the LAO observed in the magnetic properties of the samples correspond mainly to topographical changes of the surface. Changes in the magnetic properties induced by LAO or by a variability of sputtered layers could lead to the further production of magnetic printed circuit or photonic nanostructures.

  18. The mechanism of sputter-induced orientation change in YBCO films on MgO (001)

    International Nuclear Information System (INIS)

    Huang, Y.; Vuchic, B.V.; Baldo, P.; Merkle, K.L.; Buchholz, D.B.; Mahajan, S.; Lei, J.S.; Markworth, P.R.; Chang, R.P.H.

    1996-12-01

    The mechanisms of the sputter-induced orientation change in YBa 2 Cu 3 O 7-x (YBCO) films grown on MgO (001) substrates by pulsed organometallic beam epitaxy (POMBE) are investigated by x-ray diffraction. Rutherford backscatter spectroscopy (RBS), cross-section TEM (XTEM) and microanalysis. It is found that the W atom implantation concurring with the ion sputtering plays an important role in effecting the orientation change. This implantation changes the surface structure of the substrate and induces an intermediate layer in the initial growth of the YBCO film, which in turn acts as a template that induces the orientation change. It seems that the surface morphology change caused by ion sputtering has only a minor effect on the orientation change

  19. Construction of a sputtering reactor for the coating and processing of monolithic U-Mo nuclear fuel

    International Nuclear Information System (INIS)

    Schmid, Wolfgang

    2011-01-01

    In the presented thesis sputter deposition was used for the first time to coat monolithic U-Mo nuclear fuel foils with diffusion inhibitive materials. The intention of these coatings is to prevent the formation of an interdiffusion layer between U-Mo and Al cladding during the use of the fuel. A small sputtering reactor was built, in which the method was tested and processing parameters were investigated. In parallel a larger sputtering reactor was constructed, that allows to coat full size monolithic U-Mo nuclear fuel foils and was used to test an industrial application of the technique. As a result a method based on sputter deposition and erosion can be presented, that allows to clean as well as to coat the surface of monolithic U-Mo nuclear fuel foils in excellent quality. It can be included at any time into the manufacturing chain for U-Mo fuel elements, which is currently being developed.

  20. Magnetron sputtered zinc oxide nanorods as thickness-insensitive cathode interlayer for perovskite planar-heterojunction solar cells.

    Science.gov (United States)

    Liang, Lusheng; Huang, Zhifeng; Cai, Longhua; Chen, Weizhong; Wang, Baozeng; Chen, Kaiwu; Bai, Hua; Tian, Qingyong; Fan, Bin

    2014-12-10

    Suitable electrode interfacial layers are essential to the high performance of perovskite planar heterojunction solar cells. In this letter, we report magnetron sputtered zinc oxide (ZnO) film as the cathode interlayer for methylammonium lead iodide (CH3NH3PbI3) perovskite solar cell. Scanning electron microscopy and X-ray diffraction analysis demonstrate that the sputtered ZnO films consist of c-axis aligned nanorods. The solar cells based on this ZnO cathode interlayer showed high short circuit current and power conversion efficiency. Besides, the performance of the device is insensitive to the thickness of ZnO cathode interlayer. Considering the high reliability and maturity of sputtering technique both in lab and industry, we believe that the sputtered ZnO films are promising cathode interlayers for perovskite solar cells, especially in large-scale production.

  1. Optical and electronic proprieties of thin films based on (Z-5-(4-chlorobenzylidene-3-(2-ethoxyphenyl-2 thioxothiazolidin-4-one, (CBBTZ and possible application as exciton-blocking layer in heterojunction organic solar cells

    Directory of Open Access Journals (Sweden)

    Morsli M.

    2012-06-01

    Full Text Available In this work, organic thin film solar cells with structures based on CuPc/C60 bulk heterojunctions, have been fabricated and characterized. The effect of introducing an exciton blocking layer (EBL between the active layer and the metal layer in the solar cell was investigated. For that (Z-5-(4-chlorobenzylidene-3-(2-ethoxyphenyl-2-thioxothiazolidin-4-one, that we called (CBBTZ has been synthesized, characterized and probed as EBL. It was shown that optimized structures containing EBLs resulted in an improvement in solar cell conversion efficiencies. The energy levels corresponding to the highest occupied molecular orbital (HOMO and the lowest unoccupied molecular orbital (LUMO of the CBBTZ have been determined from the first oxidation and reduction potential respectively, using cyclic voltametric (CV measurements. From CV curves, CBBTZ in dichloromethane showed a one electron reversible reduction and oxidation waves. The values of its HOMO and LUMO have been estimated to be 6.42 eV and 3.42 eV respectively. Such values show that CBBTZ could be probed as EBL in organic solar cells based on the ED/EA couple copper phthalocyanine(CuPc/fullerene (C60. The photovoltaic solar cells have been obtained by sequential deposition under vacuum of the different films where their thicknesses were measured in situ by a quartz monitor. When obtained, the averaged efficiency of the cells using the CBBTZ is higher than that achieved without EBL layer.

  2. Electrochromism of sputtered tungstic oxide films

    International Nuclear Information System (INIS)

    Tatsuoka, Hirokazu; Urabe, Kazuo; Kitao, Michihiko; Yamada, Shoji

    1985-01-01

    Electrochromism of tungstic oxide films were investigated. The films were prerared by r.f. sputtering from compressed WO 3 target under various total pressure and O 2 content of Ar-O 2 mixed sputtering atmosphere. Blue films were obtained under low total pressure of sputtering atmosphere with low content of O 2 . These films could be colored more deeply by the conventional electrochemical procedure, but could not be bleached to transparent states. Transparent films were obtained under the condition of high total pressure or high O 2 content of sputtering atmosphere. The transparent films prepared under high pressure show good electrochromic behavior after aging process. During the aging process, ''passive protons'' are injected into WO 3 matrix, where the ''passive proton'' means that it has no influence on electrochromic absorption band, and is not able to be extracted electrochemically. (author)

  3. Alkali metal adsorbate sputtering by molecular impact

    International Nuclear Information System (INIS)

    Moran, J.P.; Wachman, H.Y.; Trilling, L.

    1974-01-01

    An exploratory study of the sputtering by a krypton molecular beam of rubidium adsorbed at low coverage on a tungsten substrate has been described in a previous paper. An extension of this work is reported now

  4. Electrical resistivity of sputtered molybdenum films

    International Nuclear Information System (INIS)

    Nagano, J.

    1980-01-01

    The electrical resistivity of r.f. sputtered molybdenum films of thickness 5-150 nm deposited on oxidized silicon substrates was resolved into the three electron scattering components: isotropic background scattering, scattering at grain boundaries and scattering at surfaces. It was concluded that the isotropic background scattering is almost equal to that of bulk molybdenum and is not influenced by sputtering and annealing conditions. When the film thickness is sufficient that surface scattering can be ignored, the decrease in film resistivity after annealing is caused by the decrease in scattering at the grain boundaries for zero bias sputtered films, and is caused by an increase of the grain diameter for r.f. bias sputtered films. (Auth.)

  5. Sputtering yield measurements on single crystal cobalt

    International Nuclear Information System (INIS)

    Chernysh, V.S.; Johansen, A.; Sarholt-Kristensen, L.

    1981-01-01

    Single crystals of cobalt have been bombarded with 80 keV A + ions in the direction of the h.c.p. structure and in the direction of the f.c.c. structure. The sputtering yields, measured by the weight loss method, depend on the crystal structure, and damage, introduced by the ion bombardment, is shown to play a significant role in the explanation of the measured sputtering yields. (Auth.)

  6. Effect of sputtered flux direction on damping properties in magnetic bilayers

    Science.gov (United States)

    Nayak, Sagarika; Mallick, Sougata; Bhusan Singh, Braj; Bedanta, Subhankar

    2018-02-01

    We deposited Co40Fe40B20 (hard)/Co (soft) bilayers by varying the direction of the substrate relative to the line of impinging flux of sputtered atoms of the constituent layers. We have chosen two orientations in which the angle between the sputter flux for Co40Fe40B20 and Co layers are 0° (parallel-configuration) and 90° (perpendicular-configuration) with respect to each other. Domain imaging and the dynamic magnetic properties have been studied by performing magneto-optic Kerr effect based microscopy and ferromagnetic resonance spectroscopy, respectively. Kerr microscopy revealed that magnetic domains for the bilayers grown in different configurations exhibit a cumulative effect of the domain structure of both the single layers. However, we found that the damping constant α for the bilayers grown in the parallel-configuration exhibit lower damping as compared to the corresponding sample grown under the perpendicular-configuration.

  7. A sputtered zirconia primer for improved thermal shock resistance of plasma sprayed ceramic turbine seals

    Science.gov (United States)

    Bill, R. C.; Sovey, J.; Allen, G. P.

    1981-01-01

    The development of plasma-sprayed yttria stabilized zirconia (YSZ) ceramic turbine blade tip seal components is discussed. The YSZ layers are quite thick (0.040 to 0.090 in.). The service potential of seal components with such thick ceramic layers is cyclic thermal shock limited. The most usual failure mode is ceramic layer delamination at or very near the interface between the plasma sprayed YSZ layer and the NiCrAlY bondcoat. Deposition of a thin RF sputtered YSZ primer to the bondcoat prior to deposition of the thick plasma sprayed YSZ layer was found to reduce laminar cracking in cyclic thermal shock testing. The cyclic thermal shock life of one ceramic seal design was increased by a factor of 5 to 6 when the sputtered YSZ primer was incorporated. A model based on thermal response of plasma sprayed YSZ particles impinging on the bondcoat surface with and without the sputtered YSZ primer provides a basis for understanding the function of the primer.

  8. Block storage subsystem performance analysis

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    You feel that your service is slow because of the storage subsystem? But there are too many abstraction layers between your software and the raw block device for you to debug all this pile... Let's dive on the platters and check out how the block storage sees your I/Os! We can even figure out what those patterns are meaning.

  9. Atomic Layer Deposition of TiO2 for a High-Efficiency Hole-Blocking Layer in Hole-Conductor-Free Perovskite Solar Cells Processed in Ambient Air.

    Science.gov (United States)

    Hu, Hang; Dong, Binghai; Hu, Huating; Chen, Fengxiang; Kong, Mengqin; Zhang, Qiuping; Luo, Tianyue; Zhao, Li; Guo, Zhiguang; Li, Jing; Xu, Zuxun; Wang, Shimin; Eder, Dominik; Wan, Li

    2016-07-20

    In this study we design and construct high-efficiency, low-cost, highly stable, hole-conductor-free, solid-state perovskite solar cells, with TiO2 as the electron transport layer (ETL) and carbon as the hole collection layer, in ambient air. First, uniform, pinhole-free TiO2 films of various thicknesses were deposited on fluorine-doped tin oxide (FTO) electrodes by atomic layer deposition (ALD) technology. Based on these TiO2 films, a series of hole-conductor-free perovskite solar cells (PSCs) with carbon as the counter electrode were fabricated in ambient air, and the effect of thickness of TiO2 compact film on the device performance was investigated in detail. It was found that the performance of PSCs depends on the thickness of the compact layer due to the difference in surface roughness, transmittance, charge transport resistance, electron-hole recombination rate, and the charge lifetime. The best-performance devices based on optimized TiO2 compact film (by 2000 cycles ALD) can achieve power conversion efficiencies (PCEs) of as high as 7.82%. Furthermore, they can maintain over 96% of their initial PCE after 651 h (about 1 month) storage in ambient air, thus exhibiting excellent long-term stability.

  10. Computer simulation of sputtering of graphite target in magnetron sputtering device with two zones of erosion

    Directory of Open Access Journals (Sweden)

    Bogdanov R.V.

    2015-03-01

    Full Text Available A computer simulation program for discharge in a magnetron sputtering device with two erosion zones was developed. Basic laws of the graphite target sputtering process and transport of sputtered material to the substrate were taken into account in the Monte Carlo code. The results of computer simulation for radial distributions of density and energy flux of carbon atoms on the substrate (at different values of discharge current and pressure of the working gas confirmed the possibility of obtaining qualitative homogeneous films using this magnetron sputtering device. Also the discharge modes were determined for this magnetron sputtering device, in which it was possible to obtain such energy and density of carbon atoms fluxes, which were suitable for deposition of carbon films containing carbon nanotubes and other nanoparticles.

  11. Surface chemistry and cytotoxicity of reactively sputtered tantalum oxide films on NiTi plates

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, K. [Materials and Surface Science Institute, University of Limerick, Limerick (Ireland); Department of Physics & Energy, University of Limerick, Limerick (Ireland); Kolaj-Robin, O.; Belochapkine, S.; Laffir, F. [Materials and Surface Science Institute, University of Limerick, Limerick (Ireland); Gandhi, A.A. [Materials and Surface Science Institute, University of Limerick, Limerick (Ireland); Department of Physics & Energy, University of Limerick, Limerick (Ireland); Tofail, S.A.M., E-mail: tofail.syed@ul.ie [Materials and Surface Science Institute, University of Limerick, Limerick (Ireland); Department of Physics & Energy, University of Limerick, Limerick (Ireland)

    2015-08-31

    NiTi, an equiatomic alloy containing nickel and titanium, exhibits unique properties such as shape memory effect and superelasticity. NiTi also forms a spontaneous protective titanium dioxide (TiO{sub 2}) layer that allows its use in biomedical applications. Despite the widely perceived biocompatibility there remain some concerns about the sustainability of the alloy's biocompatibility due to the defects in the TiO{sub 2} protective layer and the presence of high amount of sub-surface Ni, which can give allergic reactions. Many surface treatments have been investigated to try to improve both the corrosion resistance and biocompatibility of this layer. For such purposes, we have sputter deposited tantalum (Ta) oxide thin films onto the surface of the NiTi alloy. Despite being one of the promising metals for biomedical applications, Ta, and its various oxides and their interactions with cells have received relatively less attention. The oxidation chemistry, crystal structure, morphology and biocompatibility of these films have been investigated. In general, reactive sputtering especially in the presence of a low oxygen mixture yields a thicker film with better control of the film quality. The sputtering power influenced the surface oxidation states of Ta. Both microscopic and quantitative cytotoxicity measurements show that Ta films on NiTi are biocompatible with little to no variation in cytotoxic response when the surface oxidation state of Ta changes. - Highlights: • Reactive sputtering in low oxygen mixture yields thicker better quality films. • Sputtering power influenced surface oxidation states of Ta. • Cytotoxicity measurements show Ta films on NiTi are biocompatible. • Little to no variation in cytotoxic response when oxidation state changes.

  12. Sputtering of molybdenum and tungsten nano rods and nodules irradiated with 150 eV argon ions

    International Nuclear Information System (INIS)

    Ghoniem, N.M.; Sehirlioglu, Alp; Neff, Anton L.; Allain, Jean-Paul; Williams, Brian; Sharghi-Moshtaghin, Reza

    2015-01-01

    Highlights: • The work was motivated by the idea of designing material surface architecture, using the CVD process, that can result in a reduction in the surface sputtering rate as compared to planar surfaces. • We present an experimental investigation of the effects of low energy (150 eV) Ar ions on surface sputtering, amorphization of near-surface layers, and the formation of surface ripples in Mo and W nano-rods and nano-nodules at room temperature. • We show that the sputtering rate decreases in all nano-architecture surfaces as compared to planar surfaces. • We discovered that energy deposition in the near surface layer in W leads to its amorphization at room temperature, to a depth of 5–10 nm. • We also show that surfaces of nano rods become rippled as a result of an ion-induced roughening instability. - Abstract: The influence of surface nano architecture on the sputtering and erosion of tungsten and molybdenum is discussed. We present an experimental investigation of the effects of low energy (150 eV) Ar ions on surface sputtering in Mo and W nano-rods and nano-nodules at room temperature. Measurements of the sputtering rate from Mo and W surfaces with nano architecture indicate that the surface topology plays an important role in the mechanism of surface erosion and restructuring. Chemical vapor deposition (CVD) is utilized as a material processing route to fabricate nano-architectures on the surfaces of W and Mo substrates. First, Re dendrites form as needles with cross-sections that have hexagonal symmetry, and are subsequently employed as scaffolding for further deposition of W and Mo to create nano rod surface architecture. The sputtering of surface atoms in these samples shows a marked dependence on their surface architecture. The sputtering rate is shown to decrease at normal ion incidence in all nano-architecture surfaces as compared to planar surfaces. Moreover, and unlike an increase in sputtering of planar crystalline surfaces, the

  13. Fabrication of hydroxyapatite thin films on polyetheretherketone substrates using a sputtering technique

    International Nuclear Information System (INIS)

    Ozeki, K.; Masuzawa, T.; Aoki, H.

    2017-01-01

    Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. A thin titanium (Ti) intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film to the PEEK substrate. The coated films were recrystallized using a hydrothermal treatment to reduce the dissolution of the HA film. The films were then characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and a UV-Vis spectrophotometer. A pull-out test was performed to measure the film-to-substrate adhesion strength, and an immersion test was performed in ultra-pure water. In the XRD patterns of the sputtered film with the Ti intermediate layer on the PEEK substrate, small HA peaks and large Ti peaks were observed. After the hydrothermal treatment, the intensity of the HA peaks increased. The transmittance of the HA films with 5 and 10 nm Ti intermediate layers was > 79% and 68%, respectively, in the visible light wavelength region (400–700 nm) after the hydrothermal treatment. The adhesion strength of the hydrothermally treated HA films increased with decreasing thickness of the Ti intermediate layer, and the strength reached 2.7 MPa with the 5-nm-thick Ti intermediate layer. In the immersion test, the HA film with a 5-nm-thick Ti intermediate layer without hydrothermal treatment exhibited a released Ti concentration of 42.0 ± 2.4 ppb. After hydrothermal treatment, the released Ti concentration decreased to 17.3 ± 1.1 ppb. - Highlights: • Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. • A thin Ti intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film. • The adhesion strength of the HA films with the Ti intermediate layer increased with decreasing thickness of the Ti layer.

  14. Computer simulation of sputtering: A review

    International Nuclear Information System (INIS)

    Robinson, M.T.; Hou, M.

    1992-08-01

    In 1986, H. H. Andersen reviewed attempts to understand sputtering by computer simulation and identified several areas where further research was needed: potential energy functions for molecular dynamics (MD) modelling; the role of inelastic effects on sputtering, especially near the target surface; the modelling of surface binding in models based on the binary collision approximation (BCA); aspects of cluster emission in MD models; and angular distributions of sputtered particles. To these may be added kinetic energy distributions of sputtered particles and the relationships between MD and BCA models, as well as the development of intermediate models. Many of these topics are discussed. Recent advances in BCA modelling include the explicit evaluation of the time in strict BCA codes and the development of intermediate codes able to simulate certain many-particle problems realistically. Developments in MD modelling include the wide-spread use of many-body potentials in sputtering calculations, inclusion of realistic electron excitation and electron-phonon interactions, and several studies of cluster ion impacts on solid surfaces

  15. Large area precision optical coatings by pulse magnetron sputtering

    Science.gov (United States)

    Frach, Peter; Gloess, Daniel; Goschurny, Thomas; Drescher, Andy; Hartung, Ullrich; Bartzsch, Hagen; Heisig, Andreas; Grune, Harald; Leischnig, Lothar; Leischnig, Steffen; Bundesmann, Carsten

    2017-05-01

    Pulse magnetron sputtering is very well suited for the deposition of optical coatings. Due to energetic activation during film growth, sputtered films are dense, smooth and show an excellent environmental stability. Films of materials like SiO2, Al2O3, Nb2O5 or Ta2O5 can be produced with very little absorption and scattering losses and are well suited for precision optics. FEP's coating plant PreSensLine, a deposition machine dedicated for the development and deposition of precision optical layer systems will be presented. The coating machine (VON ARDENNE) is equipped with dual magnetron systems (type RM by FEP). Concepts regarding machine design, process technology and process control as well as in situ monitoring are presented to realize the high demands on uniformity, accuracy and reproducibility. Results of gradient and multilayer type precision optical coatings are presented. Application examples are edge filters and special antireflective coatings for the backlight of 3D displays with substrate size up to 300 x 400mm. The machine allows deposition of rugate type gradient layers by rotating a rotary table with substrates between two sources of the dual magnetron system. By combination of the precision drive (by LSA) for the substrate movement and a special pulse parameter variation during the deposition process (available with the pulse unit UBS-C2 of FEP), it is possible to adjust the deposition rate as a function of the substrate position exactly. The aim of a current development is a technology for the uniform coating of 3D-substrates and freeform components as well as laterally graded layers.

  16. Physical sputtering of metallic systems by charged-particle impact

    Energy Technology Data Exchange (ETDEWEB)

    Lam, N.Q.

    1989-12-01

    The present paper provides a brief overview of our current understanding of physical sputtering by charged-particle impact, with the emphasis on sputtering of metals and alloys under bombardment with particles that produce knock-on collisions. Fundamental aspects of ion-solid interactions, and recent developments in the study of sputtering of elemental targets and preferential sputtering in multicomponent materials are reviewed. We concentrate only on a few specific topics of sputter emission, including the various properties of the sputtered flux and depth of origin, and on connections between sputtering and other radiation-induced and -enhanced phenomena that modify the near-surface composition of the target. The synergistic effects of these diverse processes in changing the composition of the integrated sputtered-atom flux is described in simple physical terms, using selected examples of recent important progress. 325 refs., 27 figs.

  17. Physical sputtering of metallic systems by charged-particle impact

    International Nuclear Information System (INIS)

    Lam, N.Q.

    1989-12-01

    The present paper provides a brief overview of our current understanding of physical sputtering by charged-particle impact, with the emphasis on sputtering of metals and alloys under bombardment with particles that produce knock-on collisions. Fundamental aspects of ion-solid interactions, and recent developments in the study of sputtering of elemental targets and preferential sputtering in multicomponent materials are reviewed. We concentrate only on a few specific topics of sputter emission, including the various properties of the sputtered flux and depth of origin, and on connections between sputtering and other radiation-induced and -enhanced phenomena that modify the near-surface composition of the target. The synergistic effects of these diverse processes in changing the composition of the integrated sputtered-atom flux is described in simple physical terms, using selected examples of recent important progress. 325 refs., 27 figs

  18. Growth of oxide exchange bias layers

    Science.gov (United States)

    Chaiken, A.; Michel, R.P.

    1998-07-21

    An oxide (NiO, CoO, NiCoO) antiferromagnetic exchange bias layer produced by ion beam sputtering of an oxide target in pure argon (Ar) sputtering gas, with no oxygen gas introduced into the system. Antiferromagnetic oxide layers are used, for example, in magnetoresistive readback heads to shift the hysteresis loops of ferromagnetic films away from the zero field axis. For example, NiO exchange bias layers have been fabricated using ion beam sputtering of an NiO target using Ar ions, with the substrate temperature at 200 C, the ion beam voltage at 1000V and the beam current at 20 mA, with a deposition rate of about 0.2 {angstrom}/sec. The resulting NiO film was amorphous. 4 figs.

  19. Collimated Magnetron Sputter Deposition for Mirror Coatings

    DEFF Research Database (Denmark)

    Vickery, A.; Cooper-Jensen, Carsten P.; Christensen, Finn Erland

    2008-01-01

    At the Danish National Space Center (DNSC), a planar magnetron sputtering chamber has been established as a research and production coating facility for curved X-ray mirrors for hard X-ray optics for astronomical X-ray telescopes. In the following, we present experimental evidence that a collimat......At the Danish National Space Center (DNSC), a planar magnetron sputtering chamber has been established as a research and production coating facility for curved X-ray mirrors for hard X-ray optics for astronomical X-ray telescopes. In the following, we present experimental evidence...... that a collimation of the sputtered particles is an efficient way to suppress the interfacial roughness of the produced multilayer. We present two different types of collimation optimized for the production of low roughness curved mirrors and flat mirrors, respectively....

  20. Sputtering and mixing of supported nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez-Sáez, J.C., E-mail: jc.jimenez@upm.es [Dept. Física y Química Aplicadas a la Técnica Aeronaútica, ETSIAE, Universidad Politécnica de Madrid (UPM), 28040 Madrid (Spain); Pérez-Martín, A.M.C.; Jiménez-Rodríguez, J.J. [Dept. Física Aplicada III (Electricidad y Electrónica), Facultad de Ciencias Físicas, Universidad Complutense de Madrid (UCM), 28040 Madrid (Spain)

    2013-12-01

    Sputtering and mixing of Co nanoparticles supported in Cu(0 0 1) under 1-keV argon bombardment are studied using molecular-dynamics simulations. Particles of different initial size have been considered. The cluster height decreases exponentially with increasing fluence. In nanoparticles, sputtering yield is significantly enhanced compared to bulk. In fact, the value of this magnitude depends on the cluster height. A theoretical model for sputtering is introduced with acceptable results compared to those obtained by simulation. Discrepancies happen mainly for very small particles. Mixing rate at the interface is quantified; and besides, the influence of border effects for clusters of different initial size is assessed. Mixing rate and border length–surface area ratio for the initial interface show a proportionality relation. The phenomenon of ion-induced burrowing of metallic nanoparticles is analysed.

  1. Quantitative sputter profiling at surfaces and interfaces

    International Nuclear Information System (INIS)

    Kirschner, J.; Etzkorn, H.W.

    1981-01-01

    The key problem in quantitative sputter profiling, that of a sliding depth scale has been solved by combined Auger/X-ray microanalysis. By means of this technique and for the model system Ge/Si (amorphous) the following questions are treated quantitatively: shape of the sputter profiles when sputtering through an interface and origin of their asymmetry; precise location of the interface plane on the depth profile; broadening effects due to limited depth of information and their correction; origin and amount of bombardment induced broadening for different primary ions and energies; depth dependence of the broadening, and basic limits to depth resolution. Comparisons are made to recent theoretical calculations based on recoil mixing in the collision cascade and very good agreement is found

  2. Sputtering as a means of depth profiling

    International Nuclear Information System (INIS)

    Whitton, J.L.

    1978-01-01

    Probably the most common technique for determination of depth profiles by sputtering is that of secondary ion mass spectrometry. Many problems occur in the important step of converting the time (of sputtering) scale to a depth scale and these problems arise before the secondary ions are ejected. An attempt is made to present a comprehensive list of the effects that should be taken into consideration in the use of sputtering as a means of depth profiling. The various parameters liable to affect the depth profile measurements are listed in four sections: beam conditions; target conditions; experimental environment; and beam-target interactions. The effects are discussed and where interplay occurs, cross-reference is made and examples are provided where possible. (B.R.H.)

  3. Modelling of current-voltage characteristics of infrared photo-detectors based on type – II InAs/GaSb super-lattice diodes with unipolar blocking layers

    Directory of Open Access Journals (Sweden)

    Vishnu Gopal

    2015-09-01

    Full Text Available It is shown that current-voltage characteristics of infrared photo-detectors based on type-II InAs/GaSb super-lattices with uni-polar blocking layers can be modelled similar to a junction diode with a finite series resistance on account of blocking barriers. As an example this paper presents the results of a study of current-voltage characteristics of a type II InAs/GaSb super-lattice diode with PbIbN architecture using a recently proposed [J. Appl. Phys. 116, 084502 (2014] method for modelling of illuminated photovoltaic detectors. The thermal diffusion, generation – recombination (g-r, and ohmic currents are found as principal components besides a component of photocurrent due to background illumination. The experimentally observed reverse bias diode current in excess of thermal current (diffusion + g-r, photo-current and ohmic shunt current is reported to be best described by an exponential function of the type, Iexcess = Ir0 + K1exp(K2 V, where Ir0, K1 and K2 are fitting parameters and V is the applied bias voltage. The present investigations suggest that the exponential growth of excess current with the applied bias voltage may be taking place along the localized regions in the diode. These localized regions are the shunt resistance paths on account of the surface leakage currents and/or defects and dislocations in the base of the diode.

  4. Effects of Sputtering Parameters on AlN Film Growth on Flexible Hastelloy Tapes by Two-Step Deposition Technique.

    Science.gov (United States)

    Peng, Bin; Gong, Dongdong; Zhang, Wanli; Jiang, Jianying; Shu, Lin; Zhang, Yahui

    2016-08-10

    AlN thin films were deposited on flexible Hastelloy tapes and Si (100) substrate by middle-frequency magnetron sputtering. A layer of Y₂O₃ films was used as a buffer layer for the Hastelloy tapes. A two-step deposition technique was used to prepare the AlN films. The effects of deposition parameters such as sputtering power, N₂/Ar flow rate and sputtering pressure on the microstructure of the AlN thin films were systematically investigated. The results show that the dependency of the full width at half maximum (FWHM) of AlN/Y₂O₃/Hastelloy on the sputtering parameters is similar to that of AlN/Si (100). The FWHM of the AlN (002) peak of the prepared AlN films decreases with increasing sputtering power. The FWHM decreases with the increase of the N₂/Ar flow rate or sputtering pressure, and increases with the further increase of the N₂/Ar flow rate or sputtering pressure. The FWHM of the AlN/Y₂O₃/Hastelloy prepared under optimized parameters is only 3.7° and its root mean square (RMS) roughness is 5.46 nm. Based on the experimental results, the growth mechanism of AlN thin films prepared by the two-step deposition process was explored. This work would assist us in understanding the AlN film's growth mechanism of the two-step deposition process, preparing highly c-axis-oriented AlN films on flexible metal tapes and developing flexible surface acoustic wave (SAW) sensors from an application perspective.

  5. Photonometers for coating and sputtering machines

    Science.gov (United States)

    Oupický, P.; Jareš, D.; Václavík, J.; Vápenka, D.

    2013-04-01

    The concept of photonometers (alternative name of optical monitor of a vacuum deposition process) for coating and sputtering machines is based on photonometers produced by companies like SATIS or HV Dresden. Photometers were developed in the TOPTEC centre and its predecessor VOD (Optical Development Workshop of Institut of Plasma Physics AS CR) for more than 10 years. The article describes current status of the technology and ideas which will be incorporated in next development steps. Hardware and software used on coating machines B63D, VNA600 and sputtering machine UPM810 is presented.

  6. Sputtering erosion of fusion reactor cavity walls

    International Nuclear Information System (INIS)

    Bohachevsky, I.O.; Hafer, J.F.

    1976-12-01

    Devised are functions that describe the empirically and theoretically determined behavior of sputtering coefficients. These functions are used in a computer program that calculates erosion rates and total erosion of surfaces bombarded by ion beams of specified intensity. Presented here are analytic expressions that describe the effects of ion energy and angle of incidence, computational procedures, and results. Results, computed for alpha, triton, deuteron, and heavy-metal ions bombarding niobium, carbon, and iron surfaces indicate that for pellets with heavy metal shell structures sputtering erosion should be carefully considered and properly designed for

  7. Dependence of sputtering coefficient on ion dose

    International Nuclear Information System (INIS)

    Colligon, J.S.; Patel, M.H.

    1977-01-01

    The sputtering coefficient of polycrystalline gold bombarded by 10-40 keV Ar + ions had been measured as a function of total ion dose and shown to exhibit oscillations in magnitude between 30 and 100%. Possible experimental errors which would give rise to such an oscillation have been considered, but it is apparent that these factors are unable to explain the measurements. It is proposed that a change in the Sublimation Energy associated with either bulk damage or formation of surface topographical features arising during ion bombardment may be responsible for the observed variations in sputtering coefficient. (author)

  8. Sputtering yield calculation for binary target

    International Nuclear Information System (INIS)

    Jimenez-Rodriguez, J.J.; Rodriguez-Vidal, M.; Valles-Abarca, J.A.

    1979-01-01

    The generalization for binary targets, of the ideas proposed by Sigmund for monoatomic targets, leads to a set of coupled intergrodifferential equations for the sputtering functions. After moment decomposition, the final formulae are obtained by the standard method based on the Laplace Transform, where the inverse transform is made with the aid of asymptotic expansions in the limit of very high projectile energy as compared to the surface binding energy. The possible loss of stoichiometry for binary targets is analyzed. Comparison of computed values of sputtering yield for normal incidence, with experimental results shows good agreement. (author)

  9. Sputtering target made by hot isostatic compaction

    International Nuclear Information System (INIS)

    Wright, R.J.; Hecht, R.J.; Fenton, R.J.

    1979-01-01

    In a method of making a cooled sputtering target assembly, material to be sputtered is in powder form which is isostatically hot-pressed in a toroidal metallic container under conditions which promote compaction and bonding of the powder particles to form a dense material. Parts of the container are then removed from the target material except for a remnant around the outer surface of the target material. A cooling jacket is then fabricated and attached around the remnant of the container. The targets specified are made from MCrAlY type alloys where M is Fe, Co or Ni. (U.K.)

  10. Properties of AlN thin films deposited by means of magnetron sputtering for ISFET applications

    Directory of Open Access Journals (Sweden)

    Firek Piotr

    2015-12-01

    Full Text Available This work presents the investigations of AlN thin films deposited on Si substrates by means of magnetron sputtering. Nine different sputtering processes were performed. Based on obtained results, the tenth process was prepared and performed (for future ISFET structures manufacturing. Round aluminum (Al electrodes were evaporated on the top of deposited layers. The MIS capacitor structures enabled a subsequent electrical characterization of the AlN films by means of current-voltage (I-V and capacitance-voltage (C-V measurements. Based on these results, the main parameters of investigated layers were obtained. Moreover, the paper describes the technology of fabrication and electrical characterization of ISFET transistors and possibility of their application as ion sensors.

  11. Angular distributions of sputtered particles from lithium-implanted aluminium and copper crystals

    International Nuclear Information System (INIS)

    Johansen, A.; Johnson, E.; Sarholt-Kristensen, L.; Steenstrup, S.; Andersen, H.H.; Buhanov, V.M.; Chernysh, V.S.; Ivanov, I.N.; Minnebaev, K.F.

    1991-01-01

    The anisotropy of angular distributions of sputtered ions from lithium implanted aluminium and copper single crystals, measured by SIMS analysis, have been used to obtain information about the microstructure of the implanted layers. Sputtered Al + distributions from the {111} surface show three-fold symmetry with maximum intensity near the and directions respectively, while Li + distributions show maximum intensity only in the directions. From {100} crystals the Al + distributions have four-fold symmetry while there are no preferential ejection directions for the Li + ions. This agrees conceptually with the fact that the implanted layer contains the ordered Al 3 Li (δ') phase, which has earlier been observed by TEM analysis on implanted samples. In contrast, a similar study of Li + implanted copper crystals shows that the implanted lithium is randomly located. (orig.)

  12. Improving depth resolutions in positron beam spectroscopy by concurrent ion-beam sputtering

    Science.gov (United States)

    John, Marco; Dalla, Ayham; Ibrahim, Alaa M.; Anwand, Wolfgang; Wagner, Andreas; Böttger, Roman; Krause-Rehberg, Reinhard

    2018-05-01

    The depth resolution of mono-energetic positron annihilation spectroscopy using a positron beam is shown to improve by concurrently removing the sample surface layer during positron beam spectroscopy. During ion-beam sputtering with argon ions, Doppler-broadening spectroscopy is performed with energies ranging from 3 keV to 5 keV allowing for high-resolution defect studies just below the sputtered surface. With this technique, significantly improved depth resolutions could be obtained even at larger depths when compared to standard positron beam experiments which suffer from extended positron implantation profiles at higher positron energies. Our results show that it is possible to investigate layered structures with a thickness of about 4 microns with significantly improved depth resolution. We demonstrated that a purposely generated ion-beam induced defect profile in a silicon sample could be resolved employing the new technique. A depth resolution of less than 100 nm could be reached.

  13. A sputtered zirconia primer for improved thermal shock resistance of plasma-sprayed ceramic turbine seals

    Science.gov (United States)

    Bill, R. C.; Sovey, J.; Allen, G. P.

    1981-01-01

    It is shown that the application of sputtered Y2O3-stabilized ZrO2 (YSZ) primer in plasma-sprayed YSZ ceramic-coated turbine blades results in an improvement, by a factor of 5-6, in the thermal shock life of specimens with a sprayed, porous, Ni-Cr-Al-Y intermediate layer. Species with and without the primer were found to be able to survive 1000 cycles when the intermediate layer was used, but reduced laminar cracking was observed in the specimen with the primer. It is suggested that the sputtered YZS primer-induced properties are due to (1) more effective wetting and adherence of the plasma-sprayed YZS particles to the primer, and (2) the primer's retardation of impinging, molten plasma sprayed particles solidification rates, which result in a less detrimental residual stress distribution.

  14. Substantial difference in target surface chemistry between reactive dc and high power impulse magnetron sputtering

    Science.gov (United States)

    Greczynski, G.; Mráz, S.; Schneider, J. M.; Hultman, L.

    2018-02-01

    The nitride layer formed in the target race track during the deposition of stoichiometric TiN thin films is a factor 2.5 thicker for high power impulse magnetron sputtering (HIPIMS), compared to conventional dc processing (DCMS). The phenomenon is explained using x-ray photoelectron spectroscopy analysis of the as-operated Ti target surface chemistry supported by sputter depth profiles, dynamic Monte Carlo simulations employing the TRIDYN code, and plasma chemical investigations by ion mass spectrometry. The target chemistry and the thickness of the nitride layer are found to be determined by the implantation of nitrogen ions, predominantly N+ and N2+ for HIPIMS and DCMS, respectively. Knowledge of this method-inherent difference enables robust processing of high quality functional coatings.

  15. ZIF-8 Membranes with Improved Reproducibility Fabricated from Sputter-Coated ZnO/Alumina Supports

    KAUST Repository

    Yu, Jian

    2015-11-10

    Zeolitic imidazolate framework-8 (ZIF-8) membrane has shown great potential for propylene/propane separation based on molecular sieving mechanism. Although diverse synthesis strategies were applied to prepare ZIF-8 membranes, it is still a challenge for reproducible fabrication of high-quality membranes. In this study, high-quality ZIF-8 membranes were prepared through hydrothermal synthesis under the partial self-conversion of sputter-coated ZnO layer on porous α-alumina supports. The reproducibility was significantly improved, compared with that from sol-gel coated ZnO layer, due to the highly controllable sputtering deposition of ZnO precursor. The relationship between the quality of as-synthesized membrane and amount of deposited ZnO was also determined. The effect of pressure drop in C3H6/C3H8 separation on separating performance was also examined.

  16. Time dependence of carbon film deposition on SnO{sub 2}/Si using DC unbalanced magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Alfiadi, H., E-mail: yudi@fi.itb.ac.id; Aji, A. S., E-mail: yudi@fi.itb.ac.id; Darma, Y., E-mail: yudi@fi.itb.ac.id [Quantum Semiconductor and Devices Lab., Dept. of Physics, Institut Teknologi Bandung, Ganesa 10 Bandung 40132 (Indonesia)

    2014-02-24

    Carbon deposition on SnO{sub 2} layer has been demonstrated at low temperature using DC unbalanced magnetron-sputtering technique for various time depositions. Before carbon sputtering process, SnO{sub 2} thin layer is grown on silicon substrate by thermal evaporation method using high purity Sn wire and then fully oxidizes by dry O{sub 2} at 225°C. Carbon sputtering process was carried out at pressure of 4.6×10{sup −2} Torr by keeping the substrate temperature of 300 °C for sputtering deposition time of 1 to 4 hours. The properties of SnO{sub 2}/Si structure and carbon thin film on SnO{sub 2} is characterized using SEM, EDAX, XRD, FTIR, and Raman Spectra. SEM images and XRD spectra show that SnO2 thin film has uniformly growth on Si substrate and affected by annealing temperature. Raman and FTIR results confirm the formation of carbon-rich thin film on SnO{sub 2}. In addition, XRD spectra indicate that some structural change occur by increasing sputtering deposition time. Furthermore, the change of atomic structure due to the thermal annealing is analized by XRD spectra and Raman spectroscopy.

  17. Characterization of X-Ray Mirror Multilayers Sputtered in Reactive Atmospheres.

    Science.gov (United States)

    Diehl, Patrick Edward

    Multilayer structures of two or more materials have important applications in X-ray telescopes, microscopes, and lithography equipment. Adequate reflectivity values for particular X-ray wavelengths, can be obtained by selecting materials with appropriate optical constants and then depositing structures with geometries that should optimize the reflectivity and bandwidth for the specific application. Many parameters in the deposition process and the multilayer itself can adversely affect the final reflectivity. The objective of this work has been to investigate the potential benefits of adding reactive gasses to the inert atmosphere of the deposition system. All films were produced by d.c. magnetron sputtering in argon atmospheres with reactive gas addition. The microstructure and chemistry of the sputtered films were characterized using Transmission/High-Resolution Electron Microscopy, X-ray Diffraction, X-ray Photoelectron Spectroscopy, Fourier Transform Infrared Spectroscopy, Secondary Ion Mass Spectroscopy, Electron Probe Microanalysis, and Ion Beam Analysis with MeV helium beams. Two series of WC_{rm x}/B_4C thin-film multilayers were deposited with methane additions (up to 18%). Thin films of boron carbide and tungsten were also deposited to provide information about individual layers. High-resolution electron microscopy micrographs showed that the individual layers were completely amorphous, although diffraction studies (electron and X-ray) indicated well-defined layer ordering. Chemical analysis revealed that the multilayers contained significant levels of hydrogen, in addition to carbon. The amounts of hydrogen and carbon increased with the methane percentage, and oxygen (present in all samples) and hydrogen were preferentially incorporated into the boron carbide. The peak reflectivity for Mg K- alpha radiation depended on the methane concentration: the sample sputtered in 12% methane showed the highest reflectivity of 30%. Annealing of a representative

  18. Electronic structures of (Pb sub 2 Cu)Sr sub 2 Eu sub x Ce sub n sub - sub x Cu sub 2 O sub 2 sub n sub + sub 6 (n=2, 3): Effect of fluorite blocks between adjacent CuO sub 2 layers

    CERN Document Server

    Arai, M

    2003-01-01

    The electronic structures of (Pb sub 2 Cu)Sr sub 2 Eu sub x Ce sub n sub - sub x Cu sub 2 O sub 2 sub n sub + sub 6 (n = 2, 3) compounds which have fluorite blocks between two adjacent CuO sub 2 layers have been studied by using ab-initio method. It is found that the anisotropy is enhanced by inserting the fluorite blocks. The Fermi velocity perpendicular to the CuO sub 2 layers decreases as the thickness of fluorite blocks increases. The Eu substitution is found to affect both the atomic positions and electronic structures. The distance between apical oxygen and copper becomes shorter by the Eu substitution. The energy bands derived from oxygens in the fluorite blocks approach Fermi energy as the content of Eu substitution increases. (author)

  19. Protection of p+-n-Si Photoanodes by Sputter-Deposited Ir/IrOxThin Films

    DEFF Research Database (Denmark)

    Mei, Bastian Timo; Seger, Brian; Pedersen, Thomas

    2014-01-01

    Sputter deposition of Ir/IrOx on p+-n-Si without interfacial corrosion protection layers yielded photoanodes capable of efficient water oxidation (OER) in acidic media (1 M H2SO4). Stability of at least 18 h was shown by chronoamperomety at 1.23 V versus RHE (reversible hydrogen electrode) under 38...

  20. Optical characterisation of sputtered hydrogenated amorphous silicon thin films

    International Nuclear Information System (INIS)

    Mellassi, K.; Chafik El Idrissi, M.; Chouiyakh, A.; Rjeb, A.; Barhdadi, A.

    2000-09-01

    The present work is devoted to the study of some optical properties of hydrogenated amorphous silicon (a-Si:H) thin films prepared by radio-frequency cathodic sputtering technique. It is essentially focused on investigating separately the effects of increasing partial hydrogen pressure during the deposition stage, and the effects of post deposition thermal annealing on the main optical parameters of the deposited layers (refraction index, optical gap Urbach energy, etc.). We show that low hydrogen pressures allow a saturation of the dangling bonds in the material, while high pressures lead to the creation of new defects. We also show that thermal annealing under moderate temperatures allows a good improvement of the structural quality of deposited films. (author)

  1. Structure of DC sputtered Si-C-N thin films

    Energy Technology Data Exchange (ETDEWEB)

    Radnoczi, G.; Safran, G.; Czigany, Zs.; Berlind, T.; Hultman, L

    2003-09-01

    Si-C-N films of maximum 65 at.% of Si and maximum 40 at.% of N were prepared by reactive magnetron sputtering and their fine structure was investigated by high-resolution transmission electron microscopy. For compositions, where C-C and C-N bonds prevail, the films had anisotropic structure on the atomic scale, composed of curved graphitic layers, aligned parallel to the substrate normal. An isotropic structure was detected in the middle of the compositional triangle. On a larger scale, a columnar morphology, aligned in the direction of the deposition flux was formed in films containing more than 15 at.% of Si. Singular or simultaneous appearance of the above structures depended on film composition.

  2. Development of AlInN photoconductors deposited by sputtering

    International Nuclear Information System (INIS)

    Nunez-Cascajero, Arantzazu; Jimenez-Rodriguez, Marco; Gonzalez-Herraez, Miguel; Naranjo, Fernando B.; Monroy, Eva

    2017-01-01

    In this work, we have developed photoconductor devices based on Al 0.39 In 0.61 N layers grown on sapphire by reactive radio-frequency magnetron sputtering. The fabricated devices show a sublinear dependence of the photocurrent as a function of the incident optical power. The above-the-band-gap responsivity reaches 7 W/A for an irradiance of 10 W/m 2 (405 nm wavelength). The response decreases smoothly for below-the-bandgap excitation, dropping by more than an order of magnitude at 633 nm. The devices present persistent photoconductivity effects associated to carrier trapping at grain boundaries. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Development of AlInN photoconductors deposited by sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Nunez-Cascajero, Arantzazu; Jimenez-Rodriguez, Marco; Gonzalez-Herraez, Miguel; Naranjo, Fernando B. [Grupo de Ingenieria Fotonica, Departamento de Electronica, Universidad de Alcala, Madrid (Spain); Monroy, Eva [Universite Grenoble-Alpes, Grenoble (France); CEA-Grenoble, INAC-PHELIQS, Grenoble (France)

    2017-09-15

    In this work, we have developed photoconductor devices based on Al{sub 0.39}In{sub 0.61}N layers grown on sapphire by reactive radio-frequency magnetron sputtering. The fabricated devices show a sublinear dependence of the photocurrent as a function of the incident optical power. The above-the-band-gap responsivity reaches 7 W/A for an irradiance of 10 W/m{sup 2} (405 nm wavelength). The response decreases smoothly for below-the-bandgap excitation, dropping by more than an order of magnitude at 633 nm. The devices present persistent photoconductivity effects associated to carrier trapping at grain boundaries. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Surface sputtering in high-dose Fe ion implanted Si

    International Nuclear Information System (INIS)

    Ishimaru, Manabu

    2007-01-01

    Microstructures and elemental distributions in high-dose Fe ion implanted Si were characterized by means of transmission electron microscopy and Rutherford backscattering spectroscopy. Single crystalline Si(0 0 1) substrates were implanted at 350 deg. C with 120 keV Fe ions to fluences ranging from 0.1 x 10 17 to 4.0 x 10 17 /cm 2 . Extensive damage induced by ion implantation was observed inside the substrate below 1.0 x 10 17 /cm 2 , while a continuous iron silicide layer was formed at 4.0 x 10 17 /cm 2 . It was found that the spatial distribution of Fe projectiles drastically changes at the fluence between 1.0 x 10 17 and 4.0 x 10 17 /cm 2 due to surface sputtering during implantation

  5. Titanium carbide coatings on molybdenum by means of reactive sputtering and electron beam techniques

    International Nuclear Information System (INIS)

    Obata, T.; Aida, H.; Hirohata, Y.; Mohri, M.; Yamashina, T.

    1982-01-01

    This study is an experimental investigation of TiC coatings on Mo substrate by means of a reactive r.f. sputtering in the presence of CH 4 and a chemical reaction with interdiffusion in the sandwich structure of Ti/C/Mo by electron beam evaporation and heating. Using the reactive sputtering method, a homogeneous TiC coating with stoichiometric composition and good adhesion could be produced in the conditions of the partial pressure range of CH 4 , 2 approx. equal to 5 x 10 -4 Torr (total pressure, Psub(Ar) + Psub(CH) 4 = 5.6 x 10 -2 Torr) at 300 0 C (substrate). By using the electron beams, successively evaporated carbon and Ti on a Mo substrate was heated to 700 0 C to form a TiC surface layer on the top which then remained stable during further heating to 1000 0 C. Godd adhesion was brought about by interdiffusion to produce Mo 2 C layer between TiC layer and Mo substrate. It was also found that further heating of the coating layers subsequent to Ti evaporation on the TiC layer produced thicker TiC layer due to a chemical reaction between Ti and inner carbon layers. This could be a promising method of in situ replenishment for TiC coatings on the first wall and the limiter materials. (orig.)

  6. Aluminum oxide sputtering: a new approach to understanding the sputtering process for binary targets

    International Nuclear Information System (INIS)

    Finn, P.A.; Gruen, D.M.; Page, D.L.

    1976-01-01

    The relative abundances of the products Al, Al 2 O, and AlO sputtered in 15- and 40-kV Ar + and 15-kV H + bombardments of aluminum oxide targets (anodized film, polycrystalline disk, sapphire) are functions of the target material and of the nature, flux, and fluence of the ion beam. This finding suggests that, in collisional sputtering, the material's sensitive parameters are the surface binding energies of the sputtered species. These energies are functions of the surface composition present at the moment of a particular sputtering event and should be identified with the partial molar enthalpy of vaporization of a particular species. The aluminum oxide species--Al, Al 2 O, AlO, Al 2 O 2 , AlO 2 , Al(O 2 ) 2 , and AlO 3 --are characterized by matrix isolation spectroscopy aided by O 18 isotopic substitution experiments. 12 figures, 4 tables

  7. Reactive co-sputter deposition of nanostructured cermet anodes for solid oxide fuel cells

    Science.gov (United States)

    Ionov, Igor V.; Solovyev, Andrey A.; Shipilova, Anna V.; Lebedynskiy, Alexey M.; Smolyanskiy, Egor A.; Lauk, Alexander L.; Semenov, Vyacheslav A.

    2018-01-01

    The impact of a nanostructured NiO/yttria-stabilized zirconia (NiO/YSZ) and NiO/gadolinia-doped ceria (NiO/GDC) anode functional layers on low- and intermediate-temperature solid oxide fuel cell (SOFC) performance is investigated. NiO/YSZ and NiO/GDC thin films were reactively sputter-deposited by pulsed direct current magnetron sputtering from the Ni, Zr–Y, and Ce–Gd targets onto commercial NiO/YSZ substrates. Anode-supported SOFCs based on magnetron sputtered YSZ and GDC electrolytes (∼4 µm) with and without the nanostructured anode layers are fabricated. A direct comparison of the YSZ- and GDC-based SOFCs in temperature range of 600–800 and 400–600 °C is made. The performance of cells with the nanostructured anode layers significantly increases as compared to that of the cell without it, especially at lower temperatures. Increase of cells performance was achieved by reduction of the total area-specific resistance by 26–30%.

  8. A review of basic phenomena and techniques for sputter-deposition of high temperature superconducting films

    Energy Technology Data Exchange (ETDEWEB)

    Auciello, O. (Microelectronics Center of North Carolina, Research Triangle Park, NC (USA) North Carolina State Univ., Raleigh, NC (USA). Dept. of Materials Science and Engineering); Ameen, M.S.; Kingon, A.I.; Lichtenwalner, D.J. (North Carolina State Univ., Raleigh, NC (USA). Dept. of Materials Science and Engineering); Krauss, A.R. (Argonne National Lab., IL (USA))

    1990-01-01

    The processes involved in plasma and ion beam sputter-deposition of high temperature superconducting thin films are critically reviewed. Recent advances in the development of these techniques are discussed in relation to basic physical phenomena, specific to each technique, which must be understood before high quality films can be produced. Control of film composition is a major issue in sputter-deposition of multicomponent materials. Low temperature processing of films is a common goal for each technique, particularly in relation to integrating high temperature superconducting films with the current microelectronics technology. It has been understood for some time that for Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} deposition, the most intensely studied high-{Tc} compound, incorporation of sufficient oxygen into the film during deposition is necessary to produce as-deposited superconducting films at relatively substrate temperatures. Recent results have shown that with the use of suitable buffer layers, high quality Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} sputtered films can be obtained on Si substrates without the need for post-deposition anneal processing. This review is mainly focussed on issues related to sputter-deposition of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} thin films, although representative results concerning the bismuth and thallium based compounds are included. 143 refs., 11 figs.

  9. Sputtered Pd as Hydrogen Storage for a Chip-Integrated Microenergy System

    Directory of Open Access Journals (Sweden)

    E. Slavcheva

    2014-01-01

    Full Text Available The work presents a research on preparation and physical and electrochemical characterisation of dc magnetron sputtered Pd films envisaged for application as hydrogen storage in a chip-integrated hydrogen microenergy system. The influence of the changes in the sputtering pressure on the surface structure, morphology, and roughness was analysed by X-ray diffraction (XRD, scanning electron microscopy (SEM, and atomic force microscopy (AMF. The electrochemical activity towards hydrogen adsorption/desorption and formation of PdH were investigated in 0.5 M H2SO4 using the methods of cyclic voltammetry and galvanostatic polarisation. The changes in the electrical properties of the films as a function of the sputtering pressure and the level of hydrogenation were evaluated before and immediately after the electrochemical charging tests, using a four-probe technique. The research resulted in establishment of optimal sputter regime, ensuring fully reproducible Pd layers with highly developed surface, moderate porosity, and mechanical stability. Selected samples were integrated as hydrogen storage in a newly developed unitized microenergy system and tested in charging (water electrolysis and discharging (fuel cell operative mode at ambient conditions demonstrating a stable recycling performance.

  10. Initial growth and texture formation during reactive magnetron sputtering of TiN on Si(111)

    CERN Document Server

    Li, T Q; Tsuji, Y; Ohsawa, T; Komiyama, H

    2002-01-01

    The initial growth and texture formation mechanism of titanium nitride (TiN) films were investigated by depositing TiN films on (111) silicon substrates by using reactive magnetron sputtering of a Ti metallic target under a N sub 2 /Ar atmosphere, and then analyzing the films in detail by using transmission electron microscopy (TEM) and x-ray diffraction (XRD). Two power sources for the sputtering, dc and rf, were compared. At the initial growth stage, a continuous amorphous film containing randomly oriented nuclei was observed when the film thickness was about 3 nm. The nuclei grew and formed a polycrystalline layer when the film thickness was about 6 nm. As the film grew further, its orientation changed depending on the deposition conditions. For dc sputtering, the appearance of (111) or (200)-preferred orientations depended on the N sub 2 partial pressure, and the intensity of the preferred orientation increased with increasing film thickness. For rf sputtering, however, when the film thickness was small (...

  11. Morphology of ion-sputtered surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Makeev, Maxim A. E-mail: makeev@baton.phys.lsu.edu; Cuerno, Rodolfo; Barabasi, Albert-Laszlo

    2002-12-01

    We derive a stochastic nonlinear continuum equation to describe the morphological evolution of amorphous surfaces eroded by ion bombardment. Starting from Sigmund's theory of sputter erosion, we calculate the coefficients appearing in the continuum equation in terms of the physical parameters characterizing the sputtering process. We analyze the morphological features predicted by the continuum theory, comparing them with the experimentally reported morphologies. We show that for short time scales, where the effect of nonlinear terms is negligible, the continuum theory predicts ripple formation. We demonstrate that in addition to relaxation by thermal surface diffusion, the sputtering process can also contribute to the smoothing mechanisms shaping the surface morphology. We explicitly calculate an effective surface diffusion constant characterizing this smoothing effect and show that it is responsible for the low temperature ripple formation observed in various experiments. At long time scales the nonlinear terms dominate the evolution of the surface morphology. The nonlinear terms lead to the stabilization of the ripple wavelength and we show that, depending on the experimental parameters, such as angle of incidence and ion energy, different morphologies can be observed: asymptotically, sputter eroded surfaces could undergo kinetic roughening, or can display novel ordered structures with rotated ripples. Finally, we discuss in detail the existing experimental support for the proposed theory and uncover novel features of the surface morphology and evolution, that could be directly tested experimentally.

  12. Sputtering of Surfaces of the Solid Hydrogens

    DEFF Research Database (Denmark)

    Schou, Jørgen; Thestrup Nielsen, Birgitte; Svendsen, Winnie Edith

    1998-01-01

    Sputtering of the solid hydrogens by electrons and ions exhibits features that may be related to quantum properties of these solids, i.e. a drastic enhancement of the yield for electron–bombarded thick deuterium films and a thermal peak at low ejection energies in the energy distribution...

  13. Pulsed dc self-sustained magnetron sputtering

    International Nuclear Information System (INIS)

    Wiatrowski, A.; Posadowski, W. M.; Radzimski, Z. J.

    2008-01-01

    The magnetron sputtering has become one of the commonly used techniques for industrial deposition of thin films and coatings due to its simplicity and reliability. At standard magnetron sputtering conditions (argon pressure of ∼0.5 Pa) inert gas particles (necessary to sustain discharge) are often entrapped in the deposited films. Inert gas contamination can be eliminated during the self-sustained magnetron sputtering (SSS) process, where the presence of the inert gas is not a necessary requirement. Moreover the SSS process that is possible due to the high degree of ionization of the sputtered material also gives a unique condition during the transport of sputtered particles to the substrate. So far it has been shown that the self-sustained mode of magnetron operation can be obtained using dc powering (dc-SSS) only. The main disadvantage of the dc-SSS process is its instability related to random arc formation. In such case the discharge has to be temporarily extinguished to prevent damaging both the magnetron source and power supply. The authors postulate that pulsed powering could protect the SSS process against arcs, similarly to reactive pulsed magnetron deposition processes of insulating thin films. To put this concept into practice, (i) the high enough plasma density has to be achieved and (ii) the type of pulsed powering has to be chosen taking plasma dynamics into account. In this article results of pulsed dc self-sustained magnetron sputtering (pulsed dc-SSS) are presented. The planar magnetron equipped with a 50 mm diameter and 6 mm thick copper target was used during the experiments. The maximum target power was about 11 kW, which corresponded to the target power density of ∼560 W/cm 2 . The magnetron operation was investigated as a function of pulse frequency (20-100 kHz) and pulse duty factor (50%-90%). The discharge (argon) extinction pressure level was determined for these conditions. The plasma emission spectra (400-410 nm range) and deposition

  14. Effect of surface morphology on the sputtering yields. I. Ion sputtering from self-affine surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Makeev, Maxim A. E-mail: makeev@usc.edu; Barabasi, Albert-Laszlo E-mail: alb@nd.edu

    2004-08-01

    As extensive experimental studies have shown, under certain conditions, ion bombardment of solid targets induces a random (self-affine) morphology on the ion-eroded surfaces. The rough morphology development is known to cause substantial variations in the sputtering yields. In this article, we present a theoretical model describing the sputter yields from random, self-affine surfaces subject to energetic ion bombardment. We employ the Sigmund's theory of ion sputtering, modified for the case of self-affine surfaces, to compute the sputter yields. We find that the changes in the sputtering yield, associated with the non-planar surface morphology, are strongly dependent on the parameters characterizing the surface roughness (such as the saturation width and the correlation length) and the incident ion beam (such as the incident ion energy and the deposited energy widths). It is shown that, for certain ranges of the parameters variations, surface roughness leads to substantial enhancements in the yield, with magnitude of the effect being more than 100%, as compared to the flat surface value. Furthermore, we find that, depending on the interplay between these parameters, the surface roughness can both enhance and suppress the sputter yields.

  15. Effect of surface morphology on the sputtering yields. II. Ion sputtering from rippled surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Makeev, Maxim A. E-mail: makeev@usc.edu; Barabasi, Albert-Laszlo E-mail: alb@nd.edu

    2004-08-01

    Off-normal ion bombardment of solid targets with energetic particles often leads to development of periodically modulated structures on the surfaces of eroded materials. Ion-induced surface roughening, in its turn, causes sputtering yield changes. We report on a comprehensive theoretical study of the effect of rippled surface morphology on the sputtering yields. The yield is computed as a function of the parameters characterizing the surface morphology and the incident ion beam, using the Sigmund's theory of ion sputtering. We find that the surface morphology development may cause substantial variations in the sputter yields, depending on a complex interplay between the parameters characterizing the ripple structure and the incident ion beam. For certain realizations of the ripple structure, the surface morphology is found to induce enhanced, relative to the flat surface value, sputtering yields. On the other hand, there exist regimes in which the sputtering yield is suppressed by the surface roughness below the flat surface result. We confront the obtained theoretical results with available experimental data and find that our model provides an excellent qualitative and, in some cases, quantitative agreement with the results of experimental studies.

  16. Effects of argon sputtering and UV-ozone radiation on the physico-chemical surface properties of ITO

    Science.gov (United States)

    Che, Hui; El Bouanani, M.

    2018-01-01

    X-ray photoelectron spectroscopy (XPS) and Ultraviolet Photoelectron Spectroscopy (UPS) were used to evaluate and determine the effects of 1 KeV Ar+ irradiation (sputtering) on the surface chemical composition and work function of Indium Thin Oxide (ITO). While Ar+ sputtering removes carbon-based surface contaminants, it also modifies the Sn-rich surface of ITO and leads to a reduction of the oxidation state of Sn from Sn4+ to Sn2+. The decrease in the work function of ITO is directly correlated to the decrease of Sn atomic concentration in the Sn-rich top surface layer and the reduction of the oxidation state of surface Sn.

  17. Sputtering of the 1020 AISI steel in abnormal glow discharge

    Science.gov (United States)

    García Zúñiga, J. A.; Sarmiento Santos, A.; Álvarez Luna, B.

    2017-12-01

    In all material treated in Sbnormal Glow Discharge (AGD) the phenomenon of sputtering occurs. In this work we study the sputtering suffered at different temperatures by AISI 1020 steel subjected to a DC discharge in two types of atmospheres. The steel samples were previously sanded until obtaining mirror brightness and subjected to the AGD plasma in the gaseous atmospheres of H2 and Ar. The temperature for each sputtering process was set in the range of 420°C to 600°C. In these samples the mass variation was measured and the yield sputtering processes was determined. Next, the simulation of the sputtering process was performed in the SRIM/TRIM 2008 software, by adjusting sputtering yield computational computations to those experimentally measured, in order to determine the energy with which the responsible ions of the sputtering collide with studied target.

  18. Measurement of partial coefficients of sputtering of titanium atoms from TiC and TiN coatings

    International Nuclear Information System (INIS)

    Vychegzhanin, G.A.; Gribanov, Yu.A.; Dikij, N.P.; Zhmurin, P.N.; Letuchij, A.N.; Matyash, P.P.; Sidokur, P.I.; Shono, D.A.

    1989-01-01

    Method of laser fluorescent spectroscopy was used to measure partial coefficients of sputtering of titanium atoms from TiC and TiN coatings under irradiation by 1 keV hydrogen ions. Irradiation was conducted in a plant with reflective discharge. Investigation of damaged layer in irradiated samples was conducted. The presence of near-the-surface layer enrichment with titanium atoms was revealed both in TiC and TiN samples. 12 refs.; 4 figs

  19. Electrical characterization of high-pressure reactive sputtered ScOx films on silicon

    International Nuclear Information System (INIS)

    Castan, H.; Duenas, S.; Gomez, A.; Garcia, H.; Bailon, L.; Feijoo, P.C.; Toledano-Luque, M.; Prado, A. del; San Andres, E.; Lucia, M.L.

    2011-01-01

    Al/ScO x /SiN x /n-Si and Al/ScO x /SiO x /n-Si metal-insulator-semiconductor capacitors have been electrically characterized. Scandium oxide was grown by high-pressure sputtering on different substrates to study the dielectric/insulator interface quality. The substrates were silicon nitride and native silicon oxide. The use of a silicon nitride interfacial layer between the silicon substrate and the scandium oxide layer improves interface quality, as interfacial state density and defect density inside the insulator are decreased.

  20. Characteristics of tin oxide-based thin film transistors prepared by DC magnetron sputtering.

    Science.gov (United States)

    Moon, Yeon-Keon; Kim, Woong-Sun; Kim, Kyung-Taek; Shin, Se-Young; Park, Jong-Wan

    2012-04-01

    Here we demonstrate the fabrication of SnO(x) thin-film transistors (TFTs), where SnO(x) thin films are deposited as an active channel layer by DC magnetron sputtering. We analyzed the effects of the oxygen partial pressure ratio and post-deposition heat treatment (PDHT) on the characteristics of the SnO(x) thin films. We found improved performance of the TFTs obtained by using interface modification with the optimized deposition condition of SnO(x) thin films. These results are helpful for fabricating oxide-TFTs, including simple binary oxide semiconductors, as an active channel layer.

  1. Sputter deposition and characterisation of hard wear-resistant Ti/TiN multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Simmonds, M.C.; Swygenhoven, H. van [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Multilayered Ti/TiN thin films have been synthesized by magnetron sputter deposition. Alternating layers of Ti and TiN with layer thickness in the 5-50 nm range are sequentially deposited. The structure of the films have been characterised by atomic force microscopy (AFM), X-ray diffraction and reflection and Auger depth profiling. The mechanical properties have been investigated using pin-on-disc wear rate testing, nanoindentation determination of hardness and micro scratch testing. (author) 1 fig., 3 refs.

  2. Synthesis of nanofibrous ZnO by magnetron sputtering and its integration in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Ghimpu, L.; Tiginyanu, I.; Pauporte, T.; Guerin, V.M.; Lupan, O.

    2013-01-01

    This work demonstrates a cost-effective synthesis of nanofibrous ZnO layers by a magnetron sputtering. We present the results of layer characterization by scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectrometry, Raman spectroscopy, and photoluminescence which are indicative of good structural properties of the layers. The nanofibrous ZnO layers proves good structural properties offering a new nanomaterial for dye-sensitized solar cells (DSCs) application. Their successful integration in DSC for solar energy conversion is demonstrated by impedance spectroscopy, and photo-current-voltage (J-V) studies.

  3. High-rate deposition of optical coatings by closed-field magnetron sputtering

    Science.gov (United States)

    Gibson, D. R.; Brinkley, I.; Waddell, E. M.; Walls, J. M.

    2005-09-01

    "Closed field" magnetron (CFM) sputtering offers a flexible and high throughput deposition process for optical coatings and thin films required in a wide range of optical applications. CFM sputtering uses two or more different metal targets to deposit multilayers comprising a wide range of dielectrics, metals and conductive oxides. Moreover, CFM provides a room temperature deposition process with high ion current density, low bias voltage and reactive oxidation in the entire volume around the rotating substrate drum carrier, thereby producing films over a large surface area at high deposition rate with excellent and reproducible optical properties. Machines based on the Closed Field are scaleable to meet a range of batch and in-line size requirements. Typically, thin film thickness control to <+/-1% is accomplished simply using time. Fine layer thickness control and deposition of graded index layers is also assisted with a specially designed rotating shutter mechanism. The CFM configuration also allows plasma treatment of surfaces prior to deposition, allowing optimisation of coating adhesion to substrates such as plastics. This paper presents data on optical, durability and environmental properties for CFM deposited optical coatings, including anti-reflection, IR blocker and colour control and thermal control filters, graded coatings, as well as conductive transparent oxides such as indium tin oxide. Benefits of the CFM sputter process for a range of optical applications are described.

  4. Deposition of multilayer optical coatings using closed-field magnetron sputtering

    Science.gov (United States)

    Gibson, D. R.; Brinkley, I.; Hall, G. W.; Waddell, E. M.; Walls, J. M.

    2006-08-01

    "Closed field" magnetron (CFM) sputtering offers a flexible and high throughput deposition process for optical coatings and thin films required in display technologies. CFM sputtering uses two or more different metal targets to deposit multilayers comprising a wide range of dielectrics, metals and conductive oxides. Moreover, CFM provides a room temperature deposition process with high ion current density, low bias voltage and reactive oxidation in the entire volume around the rotating substrate drum carrier, thereby producing films over a large surface area at high deposition rate with excellent and reproducible optical properties. Machines based on the Closed Field are scaleable to meet a range of batch and in-line size requirements. Typically, thin film thickness control to < +/-1% is accomplished simply using time, although optical monitoring can be used for more demanding applications. Fine layer thickness control and deposition of graded index layers is also assisted with a specially designed rotating shutter mechanism. This paper presents data on optical properties for CFM deposited optical coatings, including anti-reflection, IR blocker and colour control and thermal control filters, graded coatings, narrowband filters as well as conductive transparent oxides such as indium tin oxide. Benefits of the CFM sputter process are described.

  5. Production of Zr-89 using sputtered yttrium coin targets 89Zr using sputtered yttrium coin targets.

    Science.gov (United States)

    Queern, Stacy Lee; Aweda, Tolulope Aramide; Massicano, Adriana Vidal Fernandes; Clanton, Nicholas Ashby; El Sayed, Retta; Sader, Jayden Andrew; Zyuzin, Alexander; Lapi, Suzanne Elizabeth

    2017-07-01

    An increasing interest in zirconium-89 ( 89 Zr) can be attributed to the isotope's half-life which is compatible with antibody imaging using positron emission tomography (PET). The goal of this work was to develop an efficient means of production for 89 Zr that provides this isotope with high radionuclidic purity and specific activity. We investigated the irradiation of yttrium sputtered niobium coins and compared the yields and separation efficiency to solid yttrium coins. The sputtered coins were irradiated with an incident beam energy of 17.5MeV or 17.8MeV providing a degraded transmitted energy through an aluminum degrader of 12.5MeV or 12.8MeV, respectively, with various currents to determine optimal cyclotron conditions for 89 Zr production. Dissolution of the solid yttrium coin took 2h with 50mL of 2M HCl and dissolution of the sputtered coin took 15-30min with 4mL of 2M HCl. During the separation of 89 Zr from the solid yttrium coins, 77.9 ± 11.2% of the activity was eluted off in an average of 7.3mL of 1M oxalic acid whereas for the sputtered coins, 91 ± 6% was eluted off in an average of 1.2mL of 1M oxalic acid with 100% radionuclidic purity. The effective specific activity determined via DFO-SCN titration from the sputtered coins was 108±7mCi/μmol as compared to 20.3mCi/μmol for the solid yttrium coin production. ICP-MS analysis of the yttrium coin and the sputtered coins showed 99.99% yttrium removed with 178μg of yttrium in the final solution and 99.93-100% of yttrium removed with remaining range of 0-42μg of yttrium in the final solution, respectively. The specific activity calculated for the solid coin and 3 different sputtered coins using the concentration of Zr found via ICP-MS was 140±2mCi/μmol, 300±30mCi/μmol, 410±60mCi/μmol and 1719±5mCi/μmol, respectively. Labeling yields of the 89 Zr produced via sputtered targets for 89 Zr- DFO-trastuzumab were >98%. Overall, these results show the irradiation of yttrium sputtered niobium coins

  6. Pumping behavior of sputter ion pumps

    International Nuclear Information System (INIS)

    Chou, T.S.; McCafferty, D.

    The ultrahigh vacuum requirements of ISABELLE is obtained by distributed pumping stations. Each pumping station consists of 1000 l/s titanium sublimation pump for active gases (N 2 , H 2 , O 2 , CO, etc.), and a 20 l/s sputter ion pump for inert gases (methane, noble gases like He, etc.). The combination of the alarming production rate of methane from titanium sublimation pumps (TSP) and the decreasing pumping speed of sputter ion pumps (SIP) in the ultrahigh vacuum region (UHV) leads us to investigate this problem. In this paper, we first describe the essential physics and chemistry of the SIP in a very clean condition, followed by a discussion of our measuring techniques. Finally measured methane, argon and helium pumping speeds are presented for three different ion pumps in the range of 10 -6 to 10 -11 Torr. The virtues of the best pump are also discussed

  7. Electrical properties of aluminum contacts deposited by DC sputtering method for photovoltaic applications

    Science.gov (United States)

    Krawczak, Ewelina; Gułkowski, Sławomir

    2017-10-01

    The use of aluminum contacts is common in the process of silicon solar cells production because of low contact resistivity. It has also a great importance in thin film technology for photovoltaics, especially in copper-indium-gallium-diselenide (CIGS) devices. The final stage of CIGS cell production is the top contact deposition of high conductivity layer for lateral current collection. Such material has to be highly optically transparent as well. In order to make a contact, metal is deposited onto TCO layer with minimum shadowing to allow as much light as possible into device. The metal grid contact is being made by deposition of few microns of aluminum. The resistivity of the deposited material as well as resistance between the metal grid and TCO layer plays a great role in high quality solar cell production. This paper presents the results of four point probe conductivity analysis of Al thin films deposited by direct current (DC) magnetron sputtering method. Influence of technological parameters of the Al deposition process on sheet resistance of deposited layers has been showed. In order to obtain the lowest resistivity of the thin contact layer, optimal set of sputtering parameters, i.e. power applied, deposition time and deposition pressure was found. The resistivity of the contact between two adjacent Al metal fingers deposited onto transparent conductive Al-doped zinc oxide film has been also examined.

  8. Electrical properties of aluminum contacts deposited by DC sputtering method for photovoltaic applications

    Directory of Open Access Journals (Sweden)

    Krawczak Ewelina

    2017-01-01

    Full Text Available The use of aluminum contacts is common in the process of silicon solar cells production because of low contact resistivity. It has also a great importance in thin film technology for photovoltaics, especially in copper-indium-gallium-diselenide (CIGS devices. The final stage of CIGS cell production is the top contact deposition of high conductivity layer for lateral current collection. Such material has to be highly optically transparent as well. In order to make a contact, metal is deposited onto TCO layer with minimum shadowing to allow as much light as possible into device. The metal grid contact is being made by deposition of few microns of aluminum. The resistivity of the deposited material as well as resistance between the metal grid and TCO layer plays a great role in high quality solar cell production. This paper presents the results of four point probe conductivity analysis of Al thin films deposited by direct current (DC magnetron sputtering method. Influence of technological parameters of the Al deposition process on sheet resistance of deposited layers has been showed. In order to obtain the lowest resistivity of the thin contact layer, optimal set of sputtering parameters, i.e. power applied, deposition time and deposition pressure was found. The resistivity of the contact between two adjacent Al metal fingers deposited onto transparent conductive Al-doped zinc oxide film has been also examined.

  9. Nano-structuring of PTFE surface by plasma treatment, etching, and sputtering with gold

    International Nuclear Information System (INIS)

    Reznickova, Alena; Kolska, Zdenka; Hnatowicz, Vladimir; Svorcik, Vaclav

    2011-01-01

    Properties of pristine, plasma modified, and etched (by water and methanol) polytetrafluoroethylene (PTFE) were studied. Gold nanolayers sputtered on this modified PTFE have been also investigated. Contact angle, measured by goniometry, was studied as a function of plasma exposure and post-exposure aging times. Degradation of polymer chains was examined by etching of plasma modified PTFE in water or methanol. The amount of ablated and etched layer was measured by gravimetry. In the next step the pristine, plasma modified, and etched PTFE was sputtered with gold. Changes in surface morphology were observed using atomic force microscopy. Chemical structure of modified polymers was characterized by X-ray photoelectron spectroscopy (XPS). Surface chemistry of the samples was investigated by electrokinetic analysis. Sheet resistance of the gold layers was measured by two-point technique. The contact angle of the plasma modified PTFE decreases with increasing exposure time. The PTFE amount, ablated by the plasma treatment, increases with the plasma exposure time. XPS measurements proved that during the plasma treatment the PTFE macromolecular chains are degraded and oxidized and new –C–O–C–, –C=O, and –O–C=O groups are created in modified surface layer. Surface of the plasma modified PTFE is weakly soluble in methanol and intensively soluble in water. Zeta potential and XPS shown dramatic changes in PTFE surface chemistry after the plasma exposure, water etching, and gold deposition. When continuous gold layer is formed a rapid decrease of the sheet resistance of the gold layer is observed.

  10. Spectroellipsometric investigation of optical, morphological, and structural properties of reactively sputtered polycrystalline AlN films

    International Nuclear Information System (INIS)

    Easwarakhanthan, T.; Hussain, S. S.; Pigeat, P.

    2010-01-01

    The optical and morphological properties of reactively sputtered AlN films on Si substrates have been studied in this work from a self-consistent three-layer optical model developed from spectroscopic-ellipsometry analysis and validated by observations from transmission-electron microscopy, Auger electron spectroscopy, and in situ reflectance interferometry. These properties correlate to the film microstructural properties. Accordingly, the almost thickness-independent refractive index of 2.01 of the bulk AlN layer indicates its polycrystalline microstructure. This layer also appears ungraded, homogeneous, isotropic, and free of excess Al, as if grown through a steady process. The small film absorption points to the Urbach tail states produced by the structural disorder typical of such sputtered films. The films' interface layer consists of a graded Bruggeman intermix of outdiffused Si and AlN materials spreading over 10-12 nm thickness. The surface morphology includes an Al 2 O 3 -oxidized outer rough surface gradually becoming AlN bulk with diminishing amounts of Al 2 O 3 and inner pores. The increase in the surface-layer thickness, as the film grows, indicates further surface roughening due to enlarging crystals in a disoriented growth. This spectroscopic-ellipsometry analysis of AlN films has allowed us to study the effect of substrate biasing on the AlN microstructure and to place forward a new processing method for the surface smoothening of rough AlN and diamond films.

  11. Heterojunction Diodes and Solar Cells Fabricated by Sputtering of GaAs on Single Crystalline Si

    Directory of Open Access Journals (Sweden)

    Santiago Silvestre

    2015-04-01

    Full Text Available This work reports fabrication details of heterojunction diodes and solar cells obtained by sputter deposition of amorphous GaAs on p-doped single crystalline Si. The effects of two additional process steps were investigated: A hydrofluoric acid (HF etching treatment of the Si substrate prior to the GaAs sputter deposition and a subsequent annealing treatment of the complete layered system. A transmission electron microscopy (TEM exploration of the interface reveals the formation of a few nanometer thick SiO2 interface layer and some crystallinity degree of the GaAs layer close to the interface. It was shown that an additional HF etching treatment of the Si substrate improves the short circuit current and degrades the open circuit voltage of the solar cells. Furthermore, an additional thermal annealing step was performed on some selected samples before and after the deposition of an indium tin oxide (ITO film on top of the a-GaAs layer. It was found that the occurrence of surface related defects is reduced in case of a heat treatment performed after the deposition of the ITO layer, which also results in a reduction of the dark saturation current density and resistive losses.

  12. Origins of Beta Tantalum in Sputtered Coatings

    National Research Council Canada - National Science Library

    Mulligan, C

    2001-01-01

    .... Some of the most recent work has attempted to relate the energetics (i.e., atom/ion energy) of the plasma to the alpha right arrow beta transition. It has been shown that the energetics of the plasma can relate to the most crucial sputtering parameters. The most significant feature of the use of plasma energy to explain the alpha right arrow beta transition is that it relates the formation of beta-tantalum to a quantifiable measure.

  13. Sputter coating of microspherical substrates by levitation

    Science.gov (United States)

    Lowe, A.T.; Hosford, C.D.

    Microspheres are substantially uniformly coated with metals or nonmetals by simltaneously levitating them and sputter coating them at total chamber pressures less than 1 torr. A collimated hole structure comprising a parallel array of upwardly projecting individual gas outlets is machined out to form a dimple. Glass microballoons,, which are particularly useful in laser fusion applications, can be substantially uniformly coated using the coating method and apparatus.

  14. Graphene Oxide as a Monoatomic Blocking Layer

    DEFF Research Database (Denmark)

    Petersen, Søren; Glyvradal, Magni; Bøggild, Peter

    2012-01-01

    Monolayer graphene oxide (mGO) is shown to effectively protect molecular thin films from reorganization and function as an atomically thin barrier for vapor-deposited Ti/Al metal top electrodes. Fragile organic Langmuir–Blodgett (LB) films of C22 fatty acid cadmium salts (cadmium(II) behenate) were...

  15. The deconvolution of sputter-etching surface concentration measurements to determine impurity depth profiles

    International Nuclear Information System (INIS)

    Carter, G.; Katardjiev, I.V.; Nobes, M.J.

    1989-01-01

    The quasi-linear partial differential continuity equations that describe the evolution of the depth profiles and surface concentrations of marker atoms in kinematically equivalent systems undergoing sputtering, ion collection and atomic mixing are solved using the method of characteristics. It is shown how atomic mixing probabilities can be deduced from measurements of ion collection depth profiles with increasing ion fluence, and how this information can be used to predict surface concentration evolution. Even with this information, however, it is shown that it is not possible to deconvolute directly the surface concentration measurements to provide initial depth profiles, except when only ion collection and sputtering from the surface layer alone occur. It is demonstrated further that optimal recovery of initial concentration depth profiles could be ensured if the concentration-measuring analytical probe preferentially sampled depths near and at the maximum depth of bombardment-induced perturbations. (author)

  16. Biomineralization capability of adherent bio-glass films prepared by magnetron sputtering.

    Science.gov (United States)

    Stan, G E; Pina, S; Tulyaganov, D U; Ferreira, J M F; Pasuk, I; Morosanu, C O

    2010-04-01

    Radiofrequency magnetron sputtering deposition at low temperature (150 degrees C) was used to deposit bioactive glass coatings onto titanium substrates. Three different working atmospheres were used: Ar 100%, Ar + 7%O(2), and Ar + 20%O(2). The preliminary adhesion tests (pull-out) produced excellent adhesion values (approximately 75 MPa) for the as-deposited bio-glass films. Bioactivity tests in simulated body fluid were carried out for 30 days. SEM-EDS, XRD and FTIR measurements were performed. The tests clearly showed strong bioactive features for all the prepared films. The best biomineralization capability, expressed by the thickest chemically grown carbonated hydroxyapatite layer, was obtained for the bio-glass coating sputtered in a reactive atmosphere with 7% O(2).

  17. Effect of surface texture by ion beam sputtering on implant biocompatibility and soft tissue attachment

    Science.gov (United States)

    Gibbons, D. F.

    1977-01-01

    The objectives in this report were to use the ion beam sputtering technique to produce surface textures on polymers, metals, and ceramics. The morphology of the texture was altered by varying both the width and depth of the square pits which were formed by ion beam erosion. The width of the ribs separating the pits were defined by the mask used to produce the texture. The area of the surface containing pits varies as the width was changed. The biological parameters used to evaluate the biological response to the texture were: (1) fibrous capsule and inflammatory response in subcutaneous soft tissue; (2) strength of the mechanical attachment of the textured surface by the soft tissue; and (3) morphology of the epidermal layer interfacing the textured surface of percutaneous connectors. Because the sputter yield on teflon ribs was approximately an order of magnitude larger than any other material the majority of the measurements presented in the report were obtained with teflon.

  18. Low energy hydrogen and deuterium sputtering measurements of stainless steel, graphite, and beryllium oxide

    International Nuclear Information System (INIS)

    Borders, J.A.; Langley, R.A.; Wilson, K.L.

    1978-01-01

    The total erosion yields of 304 stainless steel by low energy hydrogen and deuterium have been determined by 4 He ion backscattering spectroscopy at energies ranging from 0.33 to 9.0 keV. This experimental method determines the number of atoms removed by sputtering by measuring the change in depth of implanted Xe marker atoms. Data for 304 stainless steel are compared with the extensive published data obtained using the weight loss technique. The Xe marker method is used to make the first measurements of deuterium erosion on polycrystalline graphite. Deuterium erosion measurements of thermally-prepared oxide layers on Be were also made using 4 He backscattering spectroscopy to determine directly the number of removed atoms. These new data for the sputtering yields of deuterium on carbon and BeO range from 0.016 to 0.052 atoms per ion

  19. Catalytic growth of ZnO nanostructures by r.f. magnetron sputtering

    Directory of Open Access Journals (Sweden)

    Arroyo-Hernández María

    2011-01-01

    Full Text Available Abstract The catalytic effect of gold seed particles deposited on a substrate prior to zinc oxide (ZnO thin film growth by magnetron sputtering was investigated. For this purpose, selected ultra thin gold layers, with thicknesses close to the percolation threshold, are deposited by thermal evaporation in ultra high vacuum (UHV conditions and subsequently annealed to form gold nanodroplets. The ZnO structures are subsequently deposited by r.f. magnetron sputtering in a UHV chamber, and possible morphological differences between the ZnO grown on top of the substrate and on the gold are investigated. The results indicate a moderate catalytic effect for a deposited gold underlayer of 4 nm, quite close to the gold thin film percolation thickness.

  20. Influence of the microstructure on the corrosion behavior of magnetron sputter-quenched amorphous metallic alloys

    Science.gov (United States)

    Thakoor, A. P.; Khanna, S. K.; Williams, R. M.; Landel, R. F.

    1983-01-01

    The microstructure and corrosion behavior of magnetron sputter deposited amorphous metallic films of (Mo6ORu40)82B18 under varying sputtering atmospheres have been investigated. The microstructural details and topology of the films have been studied by scanning electron microscopy and correlated with the deposition conditions. By reducing the pressure of pure argon gas, the characteristic features of rough surface and columnar growth full of vertical voids can be converted into a mirror-smooth finish with very dense deposits. Films deposited in the presence of O2 or N2 exhibit columnar structure with vertical voids. Film deposited in pure argon at low pressure show remarkably high corrosion resistance due to the formation of a uniform passive surface layer. The influence of the microstructure and surface texture on the corrosion behavior is discussed.

  1. InxGa1-xAs obtained from independent target via co-sputtering deposition

    International Nuclear Information System (INIS)

    Bernal-Correa, R; Torres-Jaramillo, S.; Pulzara-Mora, C.

    2017-01-01

    This paper is focused on the preparation of InGaAs thin films on GaAs substrates by r.f. magnetron sputtering technique, using the sputtering power as control means for the formation of different stoichiometries. Results of X-ray and Raman spectroscopy allowed corroborating the formation of In x Ga 1-x As in different concentrations, identifying peaks associated with crystallographic planes (X-rays) and characteristic vibrational phonon modes (Raman). An analysis performed with the Secondary Ion Mass Spectroscopy (SIMS) and X-ray Photoelectron Spectroscopy (XPS) techniques, allowed discussing on the composition in each of the layers. Finally, an alternative in obtaining the ternary semiconductor with polycrystalline structure and preferential growth along the direction (111) was demonstrated and generated by a technique different from the epitaxial techniques, which are commonly used for the growth of III-V semiconductors. (paper)

  2. Carbon sputtering yield measurements at grazing incidence

    International Nuclear Information System (INIS)

    Kolasinski, Robert D.; Polk, James E.; Goebel, Dan; Johnson, Lee K.

    2008-01-01

    In this investigation, carbon sputtering yields were measured experimentally at varying angles of incidence under Xe + bombardment. The measurements were obtained by etching a coated quartz crystal microbalance (QCM) with a low energy ion beam. The material properties of the carbon targets were characterized with a scanning electron microscope (SEM) and Raman spectroscopy. C sputtering yields measured under Ar + and Xe + bombardment at normal incidence displayed satisfactory agreement with previously published data over an energy range of 200 eV-1 keV. For Xe + ions, the dependence of the yields on angle of incidence θ was determined for 0 o ≤ θ ≤ 80 deg. Over this range, an increase in C sputtering yield by a factor of 4.8 was observed, with the peak in yield occurring at 70 o . This is a much higher variation compared to Xe + → Mo yields under similar conditions, a difference that may be attributed to higher scattering of the incident particles transverse to the beam direction than in the case of Xe + → C. In addition, the variation of the yields with θ was not strongly energy dependent. Trapping of Xe in the surface was observed, in contrast to observations using the QCM technique with metallic target materials. Finally, target surface roughness was characterized using atomic force microscope measurements to distinguish between the effects of local and overall angle of incidence of the target

  3. Sputtered Encapsulation as Wafer Level Packaging for Isolatable MEMS Devices: A Technique Demonstrated on a Capacitive Accelerometer

    Directory of Open Access Journals (Sweden)

    Azrul Azlan Hamzah

    2008-11-01

    Full Text Available This paper discusses sputtered silicon encapsulation as a wafer level packaging approach for isolatable MEMS devices. Devices such as accelerometers, RF switches, inductors, and filters that do not require interaction with the surroundings to function, could thus be fully encapsulated at the wafer level after fabrication. A MEMSTech 50g capacitive accelerometer was used to demonstrate a sputtered encapsulation technique. Encapsulation with a very uniform surface profile was achieved using spin-on glass (SOG as a sacrificial layer, SU-8 as base layer, RF sputtered silicon as main structural layer, eutectic gold-silicon as seal layer, and liquid crystal polymer (LCP as outer encapsulant layer. SEM inspection and capacitance test indicated that the movable elements were released after encapsulation. Nanoindentation test confirmed that the encapsulated device is sufficiently robust to withstand a transfer molding process. Thus, an encapsulation technique that is robust, CMOS compatible, and economical has been successfully developed for packaging isolatable MEMS devices at the wafer level.

  4. Influence of surface topography on the sputtering yields of silver

    International Nuclear Information System (INIS)

    Pan Jisheng; Wang Zhenxia; Tao Zhenlan; Zhang Jiping

    1992-01-01

    The sputtering yields of silver have been measured as a function of the fluence of incident Ar + ions (27 keV) using the collector technique and RBS analysis. The irradiated surface was examined by scanning electron microscopy (SEM). It is shown that the sputtering yields of surfaces with topography are enhanced relative to smooth surfaces of silver, but the extent of the enhancement depends on the irradiation dose. The experimental results can be explained assuming that the surface topography and sputtering yield are a function of incident angle. It is obvious that the surface topography is an important factor to influence the sputtering yield. The term ''apparent sputtering yield'' has specifically been used when referring to the experimental sputtering yield of a surface with topography, to emphasize the difference with a smooth surface. (orig.)

  5. Recent developments in reactively sputtered optical thin films

    Energy Technology Data Exchange (ETDEWEB)

    Pawlewicz, W.T.; Martin, P.M.; Hays, D.D.; Mann, I.B.

    1981-12-01

    Highlights of a multiyear effort to develop new or improved thin film optical coating materials through the use of reactive sputtering techniques are presented. Reactive sputtering is shown to be an extremely versatile technique capable of synthesizing broad classes of materials in a straightfoward manner. The exceptional utility of sputtering for preparation of hard coatings such as oxides, nitrides and novel materials based on Si and Ge is described. Some of these coating materials cannot be made by conventional evaporative techniques. Reactive sputtering is shown to allow precise control of coating composition, microstructure and the resulting optical properties. Examples of multilayer coatings such as all-dielectric and dielectric-enhanced mirrors made from reactively sputtered materials are included, and simple yet elegant fabrication techniques are introduced. The reactive sputtering technique and equipment used specifically for optical coatings are briefly described, and comparison is made with the conventional evaporative approach.

  6. Dwell time dependent morphological transition and sputtering yield of ion sputtered Sn

    International Nuclear Information System (INIS)

    Qian, H X; Zeng, X R; Zhou, W

    2010-01-01

    Self-organized nano-scale patterns may appear on a wide variety of materials irradiated with an ion beam. Good manipulation of these structures is important for application in nanostructure fabrication. In this paper, dwell time has been demonstrated to be able to control the ripple formation and sputtering yield on Sn surface. Ripples with a wavelength of 1.7 μm were observed for a dwell time in the range 3-20 μs, whereas much finer ripples with a wavelength of 540 nm and a different orientation were observed for a shorter dwell time in the range 0.1-2 μs. The sputtering yield increases with dwell time significantly. The results provide a new basis for further steps in the theoretical description of morphology evolution during ion beam sputtering.

  7. Sputtered boron indium oxide thin-film transistors

    Science.gov (United States)

    Stewart, Kevin A.; Gouliouk, Vasily; Keszler, Douglas A.; Wager, John F.

    2017-11-01

    Boron indium oxide (BIO) is studied for thin-film transistor (TFT) channel layer applications. Sputtered BIO thin films exhibit an amorphous phase over a wide range of B2O3/In2O3 ratios and remain amorphous up to 500 °C. The band gap decreases linearly with decreasing boron content, whereas device performance generally improves with decreasing boron content. The best amorphous BIO TFT exhibits a field-effect mobility of 10 cm2 V-1 s-1, turn-on voltage of 2.5 V, and sub-threshold swing of 0.72 V/dec. Decreasing the boron content to 12.5% leads to a polycrystalline phase, but further increases the mobility up to 20-40 cm2 V-1 s-1. TCAD simulation results suggest that the reason for higher performance after increasing the anneal temperature from 200 to 400 °C is due to a lower defect density in the sub-bandgap region of the BIO channel layer.

  8. Erosion of nanostructured tungsten by laser ablation, sputtering and arcing

    Directory of Open Access Journals (Sweden)

    Dogyun Hwangbo

    2017-08-01

    Full Text Available Mass loss of nanostructured tungsten, which was formed by helium plasma irradiation, due to laser ablation, sputtering, and arcing was investigated. Below the helium sputtering energy threshold (200eV. Reduction in sputtering on nanostructured surface was observed. Arcing was initiated using laser pulses, and the erosion rate by arcing was measured. The erosion rate increased with arc current, while the erosion per Coulomb was not affected by arc current.

  9. Energy dependent neutron sputtering and surface damage cross sections

    International Nuclear Information System (INIS)

    Odette, G.R.; Doiron, D.R.; Kennerley, R.J.

    1976-01-01

    The results clearly indicate that damage function analysis might be usefully applied to define both the neutron and primary recoil energy dependence of sputtering yields. Even with relatively large data errors, it appears that it is possible to both detect the existence and indicate the form of the deviation of sputtering yield from linear damage energy dependence (if such deviation exists). This information would be very useful in developing improved models of the sputtering phenomena

  10. Flexible indium zinc oxide/Ag/indium zinc oxide multilayer electrode grown on polyethersulfone substrate by cost-efficient roll-to-roll sputtering for flexible organic photovoltaics

    International Nuclear Information System (INIS)

    Park, Yong-Seok; Kim, Han-Ki

    2010-01-01

    The authors describe the preparation and characteristics of flexible indium zinc oxide (IZO)-Ag-IZO multilayer electrodes grown on flexible polyethersulfone (PES) substrates using a roll-to-roll sputtering system for use in flexible organic photovoltaics. By the continuous roll-to-roll sputtering of the bottom IZO, Ag, and top IZO layers at room temperature, they were able to fabricate a high quality IZO-Ag-IZO multilayer electrode with a sheet resistance of 6.15 ε/square, optical transmittance of 87.4%, and figure of merit value of 42.03x10 -3 Ω -1 on the PES substrate. In addition, the IZO-Ag-IZO multilayer electrode exhibited superior flexibility to the roll-to-roll sputter grown single ITO electrode due to the existence of a ductile Ag layer between the IZO layers and stable amorphous structure of the IZO film. Furthermore, the flexible organic solar cells (OSCs) fabricated on the roll-to-roll sputter grown IZO-Ag-IZO electrode showed higher power efficiency (3.51%) than the OSCs fabricated on the roll-to-roll sputter grown single ITO electrode (2.67%).

  11. Improving the growth of Ge/Si islands by modulating the spacing between screen and accelerator grids in ion beam sputtering deposition system

    International Nuclear Information System (INIS)

    Yang, Jie; Zhao, Bo; Wang, Chong; Qiu, Feng; Wang, Rongfei; Yang, Yu

    2016-01-01

    Highlights: • Ge islands were prepared by ion beam sputtering with different grid-to-grid gaps. • Ge islands with larger sizes and low density are observed in 1-mm-spaced samples. • The island growth was determined by sputter energy and the quality of Si buffer. • The crystalline volume fraction of buffer must be higher than 72% to grow islands. - Abstract: Ge islands were fabricated on Si buffer layer by ion beam sputtering deposition with a spacing between the screen and accelerator grids of either 1 mm or 2 mm. The Si buffer layer exhibits mixed-phase microcrystallinity for samples grown with 1 mm spacing and crystallinity for those with 2 mm spacing. Ge islands are larger and less dense than those grown on the crystalline buffer because of the selective growth mechanism on the microcrystalline buffer. Moreover, the nucleation site of Ge islands formed on the crystalline Si buffer is random. Ge islands grown at different grid-to-grid gaps are characterized by two key factors, namely, divergence half angle of ion beam and crystallinity of buffer layer. High grid-to-grid spacing results in small divergence half angle, thereby enhancing the sputtering energy and redistribution of sputtered atoms. The crystalline volume fraction of the microcrystalline Si buffer was obtained based on the integrated intensity ratio of Raman peaks. The islands show decreased density with decreasing crystalline volume fraction and are difficult to observe at crystalline volume fractions lower than 72%.

  12. Sputtering materials for VLSI and thin film devices

    CERN Document Server

    Sarkar, Jaydeep

    2010-01-01

    An important resource for students, engineers and researchers working in the area of thin film deposition using physical vapor deposition (e.g. sputtering) for semiconductor, liquid crystal displays, high density recording media and photovoltaic device (e.g. thin film solar cell) manufacturing. This book also reviews microelectronics industry topics such as history of inventions and technology trends, recent developments in sputtering technologies, manufacturing steps that require sputtering of thin films, the properties of thin films and the role of sputtering target performance on overall p

  13. Data compilation of angular distributions of sputtered atoms

    International Nuclear Information System (INIS)

    Yamamura, Yasunori; Takiguchi, Takashi; Tawara, Hiro.

    1990-01-01

    Sputtering on a surface is generally caused by the collision cascade developed near the surface. The process is in principle the same as that causing radiation damage in the bulk of solids. Sputtering has long been regarded as an undesirable dirty effect which destroys the cathodes and grids in gas discharge tubes or ion sources and contaminates plasma and the surrounding walls. However, sputtering is used today for many applications such as sputter ion sources, mass spectrometers and the deposition of thin films. Plasma contamination and the surface erosion of first walls due to sputtering are still the major problems in fusion research. The angular distribution of the particles sputtered from solid surfaces can possibly provide the detailed information on the collision cascade in the interior of targets. This report presents a compilation of the angular distribution of sputtered atoms at normal incidence and oblique incidence in the various combinations of incident ions and target atoms. The angular distribution of sputtered atoms from monatomic solids at normal incidence and oblique incidence, and the compilation of the data on the angular distribution of sputtered atoms are reported. (K.I.)

  14. Serial co-sputtering. Development of a versatile coating technology and its characterization using the example of rate enhancement of metal oxides by co-doping; Serielles Co-Sputtern. Entwicklung einer flexiblen Beschichtungstechnologie und deren Charakterisierung am Beispiel der Ratenerhoehung von Metalloxiden durch Co-Dotierung

    Energy Technology Data Exchange (ETDEWEB)

    Austgen, Michael

    2011-09-19

    rotary target and the sputtering power of the secondary process (dopant concentration). The investigations show that already for low W-dopant concentrations <2 at.% in sputter deposited layers a significant rate enhancement is possible for both metal oxides (70% for Al{sub 2}O{sub 3}:W and 160% for TiO{sub 2}:W). For co-doping with the heavier element Bi no rate enhancement is observed. This result is surprising at first and is in contrast to earlier simulations. Our experiments show, however, that not only a high mass contrast of the collision partners is required for an improved momentum transfer but also a higher surface binding energy of the dopant to the target surface is necessary. A low surface binding energy leads to a high sputter yield of Bi, thus Bi is quickly sputtered away before it can contribute efficiently to the sputter yield amplification effect. This work shows the successful design, production and characterization of a serial co-sputter setup and the development of a first understanding of process dynamics in serial co-sputtering. Furthermore the first proof of the sputter yield amplification effect for metal oxides in a magnetron sputter deposition process is provided. (orig.)

  15. Measurement of neutral Ti atoms from TiC and Ti targets sputtered by low-energy H+ and Ar+ ions using laser-induced fluorescence

    International Nuclear Information System (INIS)

    Yamada, R.; Bay, H.L.; Schweer, B.

    1984-01-01

    The sputtering of Ti from TiC and also from pure Ti targets for 500 eV H + and Ar + ion irradiation at normal incidence has been investigated by laser-induced fluorescence. The sputtered neutral Ti atoms in the ground state were observed as a function of fluence and target temperature. This technique is shown to be applicable for in-situ sputtering investigations of TiC. Strong fluence dependences of the fluorescence intensities for Ti and TiC targets were observed. These results are discussed from the viewpoint of chemisorption of oxygen on the target surfaces. In the case of H + bombardment, the depleted layer of carbon atoms near the surface of TiC due to chemical sputtering should also be taken into account to explain the fluence dependence of the fluorescence intensity. No significant temperature dependence of the Ti sputtering yield of TiC for Ar + and H + ion bombardment was found in the steady state, and the physical sputtering yield of the Ti component of TiC is about half the Ti yield from a Ti target for Ar + ion bombardment. (orig.)

  16. EnviroAtlas - Memphis, TN - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Memphis, TN EnviroAtlas community. The block groups are from the US Census Bureau and are included/excluded based...

  17. EnviroAtlas - Woodbine, IA - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Woodbine, IA EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  18. EnviroAtlas - Fresno, CA - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Fresno, CA EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  19. EnviroAtlas - Portland, OR - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Portland, OR EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  20. EnviroAtlas - Cleveland, OH - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Cleveland, OH EnviroAtlas community. The block groups are from the US Census Bureau and are included/excluded...

  1. Methods of optimization of reactive sputtering conditions of Al target during AlN films deposition

    Directory of Open Access Journals (Sweden)

    Chodun Rafal

    2015-12-01

    Full Text Available Encouraged by recent studies and considering the well-documented problems occurring during AlN synthesis, we have chosen two diagnostic methods which would enable us to fully control the process of synthesis and characterize the synthesized aluminum nitride films. In our experiment we have compared the results coming from OES measurements of plasma and circulating power characteristics of the power supply with basic features of the deposited layers. The dual magnetron system operating in AC mode was used in our studies. Processes of aluminum target sputtering were carried out in an atmosphere of a mixture of argon and nitrogen. The plasma emission spectra were measured with the use of a monochromator device. Analyses were made by comparing the positions and intensities of spectral lines of the plasma components. The results obtained allowed us to characterize the sputtering process under various conditions of gas mixture compositions as well as power distribution more precisely, which is reported in this work. The measured spectra were related to the deposition rate, the structure morphology of the films and chemical composition. Our work proved that the use of plasma OES and circulating power measurements make possible to control the process of sputtering and synthesis of deposited films in situ.

  2. Effect of gold sputtering on the adhesion of porcelain to cast and machined titanium.

    Science.gov (United States)

    Khung, Rathanak; Suansuwan, Napa Sukjai

    2013-07-01

    The bond strength of porcelain to titanium is insufficient to provide a clinically acceptable alternative to existing alloys for metal ceramic restorations. The purpose of the study was to investigate the effect of gold coating on the adhesion of porcelain to titanium. Forty titanium plates (25 × 8 × 1 mm) were prepared by casting and machining procedures to make 2 groups of each type (n=10). All plates were subjected to airborne-particle abrasion with alumina powder. One of each of the cast and machined groups was gold sputtered. A layer of porcelain was built up onto the titanium plates of all groups with a conventional technique. A precrack was created at the center of the specimen. Specimens were then subjected to a 4-point bending test with a universal testing machine. The load recorded from the test was used to determine adhesion in terms of the strain energy release rate (G value). The data were analyzed with ANOVA and post hoc testing (α=.05). The interfacial area of the tested specimen was then examined with scanning electron microscopy. The G values of the gold-sputtered groups were significantly higher than those of the uncoated groups for both cast and machined groups (Ptitanium was significantly improved when titanium was sputter coated with gold in both the cast and machined groups. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  3. Withdrawn. Duplicate: Effect of gold sputtering on the adhesion of porcelain to cast and machined titanium.

    Science.gov (United States)

    Khung, Rathanak; Suansuwan, Napa Sukjai

    2013-08-01

    The bond strength of porcelain to titanium is insufficient to provide a clinically acceptable alternative to existing alloys for metal ceramic restorations. The purpose of the study was to investigate the effect of gold coating on the adhesion of porcelain to titanium. Forty titanium plates (25 × 8 × 1 mm) were prepared by casting and machining procedures to make 2 groups of each type (n=10). All plates were subjected to airborne-particle abrasion with alumina powder. One of each of the cast and machined groups was gold sputtered. A layer of porcelain was built up onto the titanium plates of all groups with a conventional technique. A precrack was created at the center of the specimen. Specimens were then subjected to a 4-point bending test with a universal testing machine. The load recorded from the test was used to determine adhesion in terms of the strain energy release rate (G value). The data were analyzed with ANOVA and post hoc testing (α=.05). The interfacial area of the tested specimen was then examined with scanning electron microscopy. The G values of the gold-sputtered groups were significantly higher than those of the uncoated groups for both cast and machined groups (Ptitanium was significantly improved when titanium was sputter coated with gold in both the cast and machined groups. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  4. Substrate dependent hierarchical structures of RF sputtered ZnS films

    Science.gov (United States)

    Chalana, S. R.; Mahadevan Pillai, V. P.

    2018-05-01

    RF magnetron sputtering technique was employed to fabricate ZnS nanostructures with special emphasis given to study the effect of substrates (quartz, glass and quartz substrate pre-coated with Au, Ag, Cu and Pt) on the structure, surface evolution and optical properties. Type of substrate has a significant influence on the crystalline phase, film morphology, thickness and surface roughness. The present study elucidates the suitability of quartz substrate for the deposition of stable and highly crystalline ZnS films. We found that the role of metal layer on quartz substrate is substantial in the preparation of hierarchical ZnS structures and these structures are of great importance due to its high specific area and potential applications in various fields. A mechanism for morphological evolution of ZnS structures is also presented based on the roughness of substrates and primary nonlocal effects in sputtering. Furthermore, the findings suggest that a controlled growth of hierarchical ZnS structures may be achieved with an ordinary RF sputtering technique by changing the substrate type.

  5. Comparison on electrically pumped random laser actions of hydrothermal and sputtered ZnO films

    International Nuclear Information System (INIS)

    Wang, Canxing; Jiang, Haotian; Li, Yunpeng; Ma, Xiangyang; Yang, Deren

    2013-01-01

    Random lasing (RL) in polycrystalline ZnO films is an intriguing research subject. Here, we have comparatively investigated electrically pumped RL behaviors of two metal-insulator-semiconductor structured devices using the hydrothermal and sputtered ZnO films as the semiconductor components, i.e., the light-emitting layers, respectively. It is demonstrated that the device using the hydrothermal ZnO film exhibits smaller threshold current and larger output optical power of the electrically pumped RL. The morphological characterization shows that the hydrothermal ZnO film is somewhat porous and is much rougher than the sputtered one, suggesting that in the former stronger multiple light scattering can occur. Moreover, the photoluminescence characterization indicates that there are fewer defects in the hydrothermal ZnO film than in the sputtered one, which means that the photons can pick up larger optical gain through stimulated emission in the hydrothermal ZnO film. Therefore, it is believed that the stronger multiple light scattering and larger optical gain contribute to the improved performance of the electrically pumped RL from the device using the hydrothermal ZnO film

  6. High rate deposition of thin film cadmium sulphide by pulsed direct current magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Lisco, F., E-mail: F.Lisco@lboro.ac.uk [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Kaminski, P.M.; Abbas, A.; Bowers, J.W.; Claudio, G. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Losurdo, M. [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR, via Orabona 4, 70126 Bari (Italy); Walls, J.M. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom)

    2015-01-01

    Cadmium Sulphide (CdS) is an important n-type semiconductor widely used as a window layer in thin film photovoltaics Copper Indium Selenide, Copper Indium Gallium (di)Selenide, Copper Zinc Tin Sulphide and Cadmium Telluride (CdTe). Cadmium Sulphide has been deposited using a number of techniques but these techniques can be slow (chemical bath deposition and Radio Frequency sputtering) or the uniformity and the control of thickness can be relatively difficult (close space sublimation). In this paper we report on the development of a process using pulsed Direct Current magnetron sputtering which allows nanometre control of thin film thickness using time only. The CdS thin films deposited in this process are highly uniform and smooth. They exhibit the preferred hexagonal structure at room temperature deposition and they have excellent optical properties. Importantly, the process is highly stable despite the use of a semi-insulating magnetron target. Moreover, the process is very fast. The deposition rate using 1.5 kW of power to a 6-inch circular magnetron was measured to be greater than 8 nm/s. This makes the process suitable for industrial deployment. - Highlights: • Pulsed DC magnetron sputtering of CdS • High deposition rate deposition • Uniform, pinhole free films.

  7. Ultra-low-pressure sputtering to improve exchange bias and tune linear ranges in spin valves

    Energy Technology Data Exchange (ETDEWEB)

    Tang, XiaoLi, E-mail: tangtang1227@163.com; Yu, You; Liu, Ru; Su, Hua; Zhang, HuaiWu; Zhong, ZhiYong; Jing, YuLan

    2017-05-01

    A series of CoFe/IrMn exchange bilayers was grown by DC-sputtering at different ultra-low argon pressures ranging from 0.008 to 0.1 Pa. This pressure range was one to two orders lower than the normal sputtering pressure. Results revealed that the exchange bias increased from 140 to 250 Oe in CoFe(10 nm)/IrMn (15 nm) bilayers of fixed thickness because of the improved crystalline structure and morphological uniformity of films. Since ferromagnetic /antiferromagnetic (FM/AF) bilayers are always used in linear magnetic sensors as detection layers, the varying exchange bias can successfully achieve tunable linear range in a crossed pinning spin valve. The linear range could be adjustable from −80 Oe – +80 Oe to −150 Oe – +150 Oe on the basis of giant magnetoresistance responses. Therefore, this method provides a simple method to tune the operating range of magnetic field sensors. - Highlights: • Increasing exchange bias was achieved in bilayer at ultra-low-pressure sputtering. • The low void density and smooth surface were achieved in low pressure. • Varying exchange bias achieved tunable linear range in spin valve.

  8. High rate deposition of thin film cadmium sulphide by pulsed direct current magnetron sputtering

    International Nuclear Information System (INIS)

    Lisco, F.; Kaminski, P.M.; Abbas, A.; Bowers, J.W.; Claudio, G.; Losurdo, M.; Walls, J.M.

    2015-01-01

    Cadmium Sulphide (CdS) is an important n-type semiconductor widely used as a window layer in thin film photovoltaics Copper Indium Selenide, Copper Indium Gallium (di)Selenide, Copper Zinc Tin Sulphide and Cadmium Telluride (CdTe). Cadmium Sulphide has been deposited using a number of techniques but these techniques can be slow (chemical bath deposition and Radio Frequency sputtering) or the uniformity and the control of thickness can be relatively difficult (close space sublimation). In this paper we report on the development of a process using pulsed Direct Current magnetron sputtering which allows nanometre control of thin film thickness using time only. The CdS thin films deposited in this process are highly uniform and smooth. They exhibit the preferred hexagonal structure at room temperature deposition and they have excellent optical properties. Importantly, the process is highly stable despite the use of a semi-insulating magnetron target. Moreover, the process is very fast. The deposition rate using 1.5 kW of power to a 6-inch circular magnetron was measured to be greater than 8 nm/s. This makes the process suitable for industrial deployment. - Highlights: • Pulsed DC magnetron sputtering of CdS • High deposition rate deposition • Uniform, pinhole free films

  9. Sputtering of Ge(001): transition between dynamic scaling regimes

    DEFF Research Database (Denmark)

    Smilgies, D.-M.; Eng, P.J.; Landemark, E.

    1997-01-01

    We have studied the dynamic behavior of the Ge(001) surface during sputtering in situ and in real time using synchrotron X-ray diffraction. We find two dynamic regimes as a function of surface temperature and sputter current which are separated by a sharp transition. The boundary between these two...

  10. Application of magnetron sputtering for producing bioactive ceramic ...

    Indian Academy of Sciences (India)

    Radio frequency (RF) magnetron sputtering is a versatile deposition technique that can produce thin, uniform, dense calcium phosphate coatings. In this paper, principle and character of magnetron sputtering is introduced, and development of the hydroxyapatite and its composite coatings application is reviewed. In addition ...

  11. Beam optics optimization of a negative-ion sputter source

    Indian Academy of Sciences (India)

    795–804. Beam optics optimization of a negative-ion sputter source. F OSSWALD£ and R REBMEISTER. Institut de Recherches Subatomiques, UMR 7500 CNRS-IN2P3/ULP, BP 28,. 67037 Strasbourg Cedex 2, France. £Email: francis.osswald@ires.in2p3.fr. Abstract. A negative-ion sputter source has been studied in order ...

  12. RF sputtering: A viable tool for MEMS fabrication

    Indian Academy of Sciences (India)

    RF sputtering: A viable tool for MEMS fabrication. 545 obtain highly c-axis oriented films, which is a requirement for these films to be piezoelectric in nature. In addition to the dielectric films, thin films of Cr, Au, Ti and Pt on silicon or glass substrates, (used for ZnO deposition) were also deposited by RF sputtering process.

  13. Lattice dynamics during electronic sputtering of solid Ne

    DEFF Research Database (Denmark)

    Dutkiewicz, L.; Pedrys, R.; Schou, Jørgen

    1997-01-01

    Electronic sputtering of solid neon has been studied with molecular dynamics. The cavity formation around an excited atom and particle migration in the surface region, as well as the sputtering process have been studied. A single atomic exciton has been observed to produce a desorption of up...

  14. Sputtering of solid nitrogen by keV helium ions

    DEFF Research Database (Denmark)

    Ellegaard, O.; Schou, Jørgen; Sørensen, H.

    1993-01-01

    Solid nitrogen has become a standard material among the frozen molecular gases for electronic sputtering. We have combined measurements of sputtering yields and energy spectra from nitrogen bombarded by 4-10 keV helium ions. The data show that the erosion is electronic rather than knockon...

  15. Sputtering of rough surfaces: a 3D simulation study

    Science.gov (United States)

    von Toussaint, U.; Mutzke, A.; Manhard, A.

    2017-12-01

    The lifetime of plasma-facing components is critical for future magnetic confinement fusion power plants. A key process limiting the lifetime of the first-wall is sputtering by energetic ions. To provide a consistent modeling of the sputtering process of realistic geometries, the SDTrimSP-code has been extended to enable the processing of analytic as well as measured arbitrary 3D surface morphologies. The code has been applied to study the effect of varying the impact angle of ions on rough surfaces on the sputter yield as well as the influence of the aspect ratio of surface structures on the 2D distribution of the local sputtering yields. Depending on the surface morphologies reductions of the effective sputter yields to less than 25% have been observed in the simulation results.

  16. Magnetron sputtering of Fe-oxides on the top of HTS YBCO films

    Energy Technology Data Exchange (ETDEWEB)

    Nurgaliev, T. [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Blagoev, B. [Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Laboratory of High Magnetic Fields and Low Temperatures, 95 Gajowicka Str., 53-421 Wroclaw (Poland); Buchkov, K. [Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Mateev, E. [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Gajda, G. [Laboratory of High Magnetic Fields and Low Temperatures, 95 Gajowicka Str., 53-421 Wroclaw (Poland); Nedkov, I. [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Kovacheva, D. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, bl. 10, 1113 Sofia (Bulgaria); Slavov, L. [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Laboratory of High Magnetic Fields and Low Temperatures, 95 Gajowicka Str., 53-421 Wroclaw (Poland); Starbova, I.; Starbov, N. [Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Nankovski, M. [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Sofia university “St. Kliment Ohridski”, Faculty of Physics, 5 James Bourchier Blvd., 1164 Sofia (Bulgaria)

    2017-05-01

    The possibilities for preparation of bilayers containing magnetic Fe-oxide (Fe-O) and high temperature superconducting (HTS) YBa{sub 2}Cu{sub 3}O{sub 7−x} (YBCO) thin films were investigated. For this purpose, Fe-O films were deposited using reactive magnetron sputtering at comparatively low temperatures T≤250 °C onto dielectric (for example, LaAlO{sub 3} (LAO)) substrates, covered with a HTS YBCO film. The sputtering of the Fe-O layer at such conditions did not lead to a crucial damage of the critical temperature T{sub C} of the YBCO film, but could affect the width of the superconducting transition. A decrease of the critical temperature of the (Fe-O)/YBCO/LAO bilayer kept at ambient conditions was observed, possibly due to the negative effects of the water vapour on the sample characteristics. The double peak structure of the imaginary component of the response signal to the AC harmonic magnetic field, observed in such a (Fe-O)/YBCO/LAO sample, was ascribed from two possible views: as a consequence of morphology determined inter- and intra-granular contributions and/or as transitions from dominant irreversible processes as Bean-Livingston barrier to vortex state chains formation. - Highlights: • Iron-oxide (Fe-O) film sputtered on the top of superconducting HTS YBCO film at not very high temperatures. • No crucially damaged superconducting properties of YBCO film during Fe-O sputtering process. • A negative effect of the ambient conditions on the critical temperature of the obtained samples. • A double peak structure of the response signal to the AC harmonic magnetic field in a (Fe-O)/YBCO/LAO is observed.

  17. Ultrathin HfON/SiO2 dual tunneling layer for improving the electrical properties of metal–oxide–nitride–oxide–silicon memory

    International Nuclear Information System (INIS)

    Liu, L.; Xu, J.P.; Chen, J.X.; Ji, F.; Huang, X.D.; Lai, P.T.

    2012-01-01

    A high-k gate stack structure with ultrathin HfON/SiO 2 as dual tunneling layer (DTL), AlN as charge storage layer (CSL) and HfAlO as blocking layer (BL) is proposed to make a charge-trapping-type metal–oxide–nitride–oxide–silicon non-volatile memory device by employing in-situ sputtering method. The validity of the structure is examined and confirmed by transmission electron microscopy. The memory window, program/erase, endurance and retention properties are investigated and compared with similar gate stack structure with Si 3 N 4 /SiO 2 as DTL, HfO 2 as CSL and Al 2 O 3 as BL. Results show that a large memory window of 3.55 V at a program/erase (P/E) voltage of + 8 V/− 15 V, high P/E speed, and good endurance and retention characteristic can be achieved using the Au/ HfAlO/AlN/(HfON/SiO 2 )/Si gate stack structure. The main mechanisms lie in the enhanced electron injection through the ultrathin high-k HfON/SiO 2 DTL with suitable band offset, high trapping efficiency of the high-k AlN material, and effective blocking role of the high-k HfAlO BL. - Highlights: ► An Au/HfAlO/AlN/(HfON/SiO 2 )/Si high-k gate stack structure is proposed. ► A band-engineered dual tunneling layer (HfON/SiO 2 ) is proposed and prepared. ► A good trade-off among the memory characteristics is obtained. ► In-situ sputtering method is employed to fabricate the gate stack structure.

  18. Experimental and analytical study of the sputtering phenomena

    International Nuclear Information System (INIS)

    Howard, P.A.

    1976-03-01

    One form of the sputtering phenomena, the heat-transfer process that occurs when an initially hot vertical surface is cooled by a falling liquid film, was examined from a new experimental approach. The sputtering front is the lowest wetted position on the vertical surface and is characterized by a short region of intense nucleate boiling. The sputtering front progresses downward at nearly a constant rate, the surface below the sputtering front being dry and almost adiabatic. This heat-transfer process is of interest in the analysis of some of the performance aspects of emergency core-cooling systems of light-water reactors. An experimental apparatus was constructed to examine the heat-transfer characteristics of a sputtering front. In the present study, a heat source of sufficient intensity was located immediately below the sputtering front, which prevented its downward progress, thus permitting detailed measurements of steady-state surface temperatures throughout a sputtering front. Experimental evidence showed the sputtering front to correspond to a critical heat-flux (CHF) phenomenon. Data were obtained with water flow rates of 350-1600 lb/sub m//hr-ft and subcoolings of 40-140 0 F on a 3 / 8 -in. solid copper rod at 1 atm. A two-dimensional analytical model was developed to describe a stationary sputtering front where the wet-dry interface corresponds to a CHF phenomena and the dry zone is adiabatic. This model is nonlinear because of the temperature dependence of the heat-transfer coefficient in the wetted region and has yielded good agreement with data. A simplified one-dimensional approximation was developed which adequately describes these data. Finally, by means of a coordinate transformation and additional simplifying assumptions, this analysis was extended to analyze moving sputtering fronts, and reasonably good agreement with reported data was shown

  19. Effect of doubly layered Ru intermediate layers in perpendicular magnetic recording tape media

    Science.gov (United States)

    Sakai, Hidetada; Saemma, Gaku; Nakagawa, Shigeki

    2014-05-01

    Si/NiFe bilayer structures are very effective to obtain c-axis orientation in both a Ru intermediate layer and a CoPtCr-SiO2 recording layer when they successively deposited on the Si/NiFe bilayer. Doubly layered Ru which consists of two Ru layers prepared at low and high sputtering gas pressures promoted c-axis orientation and well-isolated grains of the CoPtCr even when the Ru intermediate layer was very thin. Doubly layered Ru intermediate layers deposited on Si/NiFe seed layers attained suitable c-axis orientation and well-isolated grains of the CoPtCr recording layer, even though the Ru double-layer was as thin as 5 nm.

  20. On a relationship between the geometry of cones on sputtered surfaces and the angular dependence of sputtered yields

    International Nuclear Information System (INIS)

    Chadderton, L.T.

    1977-01-01

    It is widely believed that the phenomenon responsible for the familiar peak in the angular dependence of sputtered yields also gives rise to characteristic semiangles α of conical protruberances on sputtered surfaces. It is shown that α corresponds to the process giving rise to the minimum rather than the maximum. No accurate measurements of the minimum have yet been made. (Auth.)

  1. Sputtering of cryogenic films of hydrogen by keV ions

    DEFF Research Database (Denmark)

    Schou, Jørgen; Hilleret, Noel

    2009-01-01

    The sputtering yield induced by keV hydrogen ions measured at CERN and at Risø National Laboratory for solid H2 and D2 at temperatures below 4.2 K decreases with increasing film thickness from about 100 x 10(15)molecules/cm2. For a film thickness comparable to or larger than the ion range the data...... at the Risø setup are quench-condensed films, while those produced at CERN are supposed to grow with large hydrogen aggregates on top of a thin bottom layer....

  2. Development of low temperature RF magnetron sputtered ITO films on flexible substrate

    Energy Technology Data Exchange (ETDEWEB)

    Muneshwar, T.P.; Varma, V.; Meshram, N; Soni, S.; Dusane, R.O. [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India)

    2010-09-15

    Indium tin oxide (ITO) is one of the important materials used as transparent conducting oxide (TCO) layer in thin film solar cells, digital displays and other similar applications. For applications involving flexible polymeric substrates, it is important that deposition of ITO is carried out at near room temperature. This requirement puts constraint on stoichiometry leading to undesired electrical and optical properties. Effect of oxygen partial pressure on ITO films deposited on flexible Kapton {sup registered} by the RF magnetron sputtering is reported in this paper. (author)

  3. Studies of PMMA sintering foils with and without coating by magnetron sputtering Pd

    Science.gov (United States)

    Cutroneo, M.; Mackova, A.; Torrisi, L.; Vad, K.; Csik, A.; Ando', L.; Svecova, B.

    2017-09-01

    Polymethylmethacrylate thin foils were prepared by using physical and chemical processes aimed at changing certain properties. The density and the optical properties were changed obtaining clear and opaque foils. DC magnetron sputtering method was used to cover the foils with thin metallic palladium layers. The high optical absorbent foils were obtained producing microstructured PMMA microbeads with and without thin metallic coatings. Rutherford Backscattering Spectroscopy, optical investigation and microscopy were employed to characterize the prepared foils useful in the field study of laser-matter interaction.

  4. Combinatorial magnetron sputtering of AgFeO2 thin films with the delafossite structure

    OpenAIRE

    Mao, Fang; Nyberg, Tomas; Thersleff, Thomas; Andersson, Anna; Jansson, Ulf

    2016-01-01

    The main objective of this study is to demonstrate the strength of the combinatorial approach to rapidly and effectively identify suitable process parameters for the synthesis of AgFeO2 filmswith layered delafossite structure. (00l)- textured delafossite AgFeO2 thin films have been successfully deposited for the first time without post-annealing by magnetron sputtering from elemental silver and iron targets in a reactive Ar-O-2 atmosphere. Gradient filmswith a wide composition range were depo...

  5. Sputter-deposited low reflectance vanadium oxide-molybdenum oxide thin films on silicon

    Science.gov (United States)

    Nayak, Manish Kumar; Esther, A. Carmel Mary; Bera, Parthasarathi; Dey, Arjun

    2017-09-01

    A single layer antireflective, smart, crystalline and nanocolumnar pulsed RF magnetron sputtered vanadium oxide-molybdenum oxide thin film on silicon is proposed for the alternate antireflective material for silicon based futuristic solar cell application. The VO-MO film with 130 nm thickness grown at 200 W shows significant low reflectance (1% within the 500-600 nm region). The VO-MO film with lowest reflectance shows a phase transition at around 55 °C which is beneficial due to film inherent variable IR emittance behaviour which may be helpful for eliminating excess heat load generated during in-service of silicon solar cell.

  6. Spectroscopic imaging of self-organization in high power impulse magnetron sputtering plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore; Andersson, Joakim; Ni, Pavel; Anders, Andre

    2013-07-17

    Excitation and ionization conditions in traveling ionization zones of high power impulse magnetron sputtering plasmas were investigated using fast camera imaging through interference filters. The images, taken in end-on and side on views using light of selected gas and target atom and ion spectral lines, suggest that ionization zones are regions of enhanced densities of electrons, and excited atoms and ions. Excited atoms and ions of the target material (Al) are strongly concentrated near the target surface. Images from the highest excitation energies exhibit the most localized regions, suggesting localized Ohmic heating consistent with double layer formation.

  7. Modeling of magnetic properties of iron thin films deposited by RF magnetron sputtering using Preisach model

    Directory of Open Access Journals (Sweden)

    Bendjerad Adel

    2016-01-01

    Full Text Available Iron thin films were deposited on glass substrates using RF magnetron sputtering and their optimal deposition conditions were determined. The structure properties were analyzed using x-ray diffraction (XRD and their magnetic hysteresis loops were obtained by Vibrating Sample Magnetometer (VSM at room temperature. In this situation, the magnetic field is either parallel or perpendicular to the substrate plane. The main contribution of this work is to characterize the thin layers and present a mathematical model that can get best fit of the characteristics B(H. By using Preisach model, good agreement was obtained between theoretical and experimental results in both cases.

  8. Anisotropies in sputtered FeCoV films and FeCoV/Ti:N multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Clemens, D.; Vananti, A.; Terrier, C.; Boeni, P.; Schnyder, B.; Tixier, S.; Horisberger, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    SQUID and MOKE magnetometry as well as mechanical and X-ray stress analysis have been used in order to prove the magnetostrictive nature of the anisotropy in Fe{sub 0.50}Co{sub 0.48}V{sub 0.02} films and Fe{sub 0.50}Co{sub 0.48}V{sub 0.02} /Ti:N multilayers. The investigation stresses on the dependence on the sputter gas pressure and on the thickness of the deposited layer. (author) 1 fig., 6 refs.

  9. Fabricating vertically aligned ultrathin graphene nanosheets without any catalyst using rf sputtering deposition

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Jian-Hua [College of Physics and Electronic Information Science, Tianjin Normal University, Tianjin 300387 (China); Wu, Shao-Long; Yang, Yu-Mei; Zheng, Rui-Ting [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Cheng, Guo-An, E-mail: gacheng@bnu.edu.cn [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China)

    2013-07-15

    Ultrathin graphene nanosheets (GNSs) were synthesized on Si substrates by using radio frequency sputtering deposition. SEM, TEM and Raman were employed to characterize the GNSs. The GNSs are well aligned on the Si substrates with sharp edges separated and unfolded outside. The TEM observation shows that most of the GNSs are less than 10 layers. The field emission properties of the GNSs synthesized for 10 h were also studied. They show good field emission characteristics, with a low turn-on electric field of 2.522 V/μm, a large field enhancement factor, and excellent stability behavior, suggesting promising prospects in the application of field electron emitting devices.

  10. Growth of high quality AlN films on CVD diamond by RF reactive magnetron sputtering

    Science.gov (United States)

    Chen, Liang-xian; Liu, Hao; Liu, Sheng; Li, Cheng-ming; Wang, Yi-chao; An, Kang; Hua, Chen-yi; Liu, Jin-long; Wei, Jun-jun; Hei, Li-fu; Lv, Fan-xiu

    2018-02-01

    A highly oriented AlN layer has been successfully grown along the c-axis on a polycrystalline chemical vapor deposited (CVD) diamond by RF reactive magnetron sputtering. Structural, morphological and mechanical properties of the heterostructure were investigated by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Nano-indentation and Four-probe meter. A compact AlN film was demonstrated on the diamond layer, showing columnar grains and a low surface roughness of 1.4 nm. TEM results revealed a sharp AlN/diamond interface, which was characterized by the presence of a distinct 10 nm thick buffer layer resulting from the initial AlN growth stage. The FWHM of AlN (002) diffraction peak and its rocking curve are as low as 0.41° and 3.35° respectively, indicating a highly preferred orientation along the c-axis. AlN sputtered films deposited on glass substrates show a higher bulk resistivity (up to 3 × 1012 Ω cm), compared to AlN films deposited on diamond (∼1010 Ω cm). Finally, the film hardness and Young's modulus of AlN films on diamond are 25.8 GPa and 489.5 GPa, respectively.

  11. Detection of organic vapors on sputtered and annealed thin Au films

    Science.gov (United States)

    Kvitek, O.; Kopacek, V.; Reznickova, A.; Svorcik, V.

    2018-03-01

    Unique optical properties of metal nanostructures enable construction of new types of chemical sensors. Nanostructures composed of Au on glass substrate were prepared by annealing of 2-20 nm thick sputtered Au films at 300 °C for 1 h. The annealing leads to transformation of the as sputtered continuous Au layers to a nanoisland structure. The forming nanostructure shows a strong, well defined surface plasmon resonance absorption band in UV-Vis spectrum, which is useful for construction of a chemical sensor. The samples were used to detect vapors of acetone and water in an experimental testing apparatus. The achieved signal-to-noise ratio was 583 and 386 for acetone and water vapors, respectively on the nanostructure prepared from 4 nm thick Au layer. The nanostructured sensitive layers, however, showed poor signal stability; therefore a polymer overlayer was introduced to protect it. The employed polystyrene film prepared by spin-coating improved sensitivity and selectivity of the sensor, while the dynamic properties of the sensing influenced only slightly.

  12. Multilayer Optical Coating Fabrication By Ion Beam Sputter Deposition

    Science.gov (United States)

    Becker, Juergen; Scheuer, Volker

    1989-02-01

    Ion Beam Sputter Deposition (IBSD) was proven to be a useful technique for producing high performance optical coatings. However, compared to other deposition techniques, several problems remain to be solved, such as low deposition rates, small areas with homogeneous deposition rate and the problem of contamination. In the work described here, a cubic vacuum chamber has been equipped with a commercially available ion beam source, a triple stage target holder and a rotating substrate holder. The primary interest was to get a reasonable deposition rate over a sufficiently large area. Single layers of SiO2, Ta205 and TiO2 and multilayers of Si02/Ta205 were produced. Contaminants in the films were analyzed by various techniques mainly by Total-Reflection X-ray Fluorescence (TXRF). Optical properties of the coatings were investigated to study the influence of the contaminants on the performance of the optical coatings. The optical properties were characterized by the refractive index, the absorption coefficient and the scattering behaviour. Scattering losses were measured by means of Total Integrated Scattering (TIS) and Angle Resolved Scattering (ARS). The damage threshold against high-power laser pulses of 1.06 pm was determined.

  13. Growth and magnetic study of sputtered Fe/Al multilayers

    International Nuclear Information System (INIS)

    Cherif, S.M.; Bouziane, K.; Roussigne, Y.; Al-Busaidy, M.

    2007-01-01

    Brillouin light scattering (BLS) and vibrating sample magnetometry (VSM) were used to study the effect of interfacial intermixing and microstructure on the magnetic properties of DC magnetron sputtered Fe/Al multilayers (MLs) on Si(1 0 0) substrate. Three samples with nominal composition [Al (4 nm)/Fe (3.7 nm)] x18 and deposited under different negative DC bias voltages (V b = -50, -200 and -400 V) have been investigated. The X-ray diffraction results indicate that the FeAl MLs have a poor crystallinity with no evidence of the absence of B2 phase. The grazing X-ray reflectivity results suggest that the interfacial roughness and intermixing were gradually reduced from 0.7 to 0.5 nm (±0.05 nm) by increasing V b from -50 to -400 V. The magnetization measurements demonstrate the presence of in-plane uniaxial anisotropy and magnetically dead interfacial layers. The BLS results reveal spin-wave surface modes whose frequencies also depend on the applied V b . The same trend upon V b was observed for the perpendicular and in-plane anisotropies

  14. Growth and magnetic study of sputtered Fe/Al multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Cherif, S.M. [LPMTM (CNRS-UPR 9001), Universite Paris 13, 99 Av. J.B. Clement, 93430 Villetaneuse (France); Bouziane, K. [LPMTM (CNRS-UPR 9001), Universite Paris 13, 99 Av. J.B. Clement, 93430 Villetaneuse (France) and Department of Physics, College of Science, Sultan Qaboos University, P.O. Box 36, Al-Khodh 123 (Oman)]. E-mail: bouzi@squ.edu.om; Roussigne, Y. [LPMTM (CNRS-UPR 9001), Universite Paris 13, 99 Av. J.B. Clement, 93430 Villetaneuse (France); Al-Busaidy, M. [Department of Physics, College of Science, Sultan Qaboos University, P.O. Box 36, Al-Khodh 123 (Oman)

    2007-03-15

    Brillouin light scattering (BLS) and vibrating sample magnetometry (VSM) were used to study the effect of interfacial intermixing and microstructure on the magnetic properties of DC magnetron sputtered Fe/Al multilayers (MLs) on Si(1 0 0) substrate. Three samples with nominal composition [Al (4 nm)/Fe (3.7 nm)]{sub x18} and deposited under different negative DC bias voltages (V {sub b} = -50, -200 and -400 V) have been investigated. The X-ray diffraction results indicate that the FeAl MLs have a poor crystallinity with no evidence of the absence of B2 phase. The grazing X-ray reflectivity results suggest that the interfacial roughness and intermixing were gradually reduced from 0.7 to 0.5 nm ({+-}0.05 nm) by increasing V {sub b} from -50 to -400 V. The magnetization measurements demonstrate the presence of in-plane uniaxial anisotropy and magnetically dead interfacial layers. The BLS results reveal spin-wave surface modes whose frequencies also depend on the applied V{sub b}. The same trend upon V {sub b} was observed for the perpendicular and in-plane anisotropies.

  15. AlN/Al dual protective coatings on NdFeB by DC magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Li Jinlong; Mao Shoudong; Sun Kefei [Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Li Xiaomin [Shanghai Institute of Ceramics Chinese Academy of Sciences, Shanghai 200050 (China); Song Zhenlun [Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)], E-mail: songzhenlun@nimte.ac.cn

    2009-11-15

    AlN/Al dual protective coatings were prepared on NdFeB by DC magnetron sputtering in a home-made industrial apparatus. Comparing with Al coating, AlN/Al coatings have a denser structure of an outmost AlN amorphous layer following an inner Al columnar crystal layer. The coatings and NdFeB substrate combine well, and moreover, there is occurrence of metallurgy bonding in the interface layer. Both Al and AlN/Al coatings have a good protective ability to NdFeB. Especially, the corrosion resistance of AlN/Al coated NdFeB is improved largely. AlN/Al and Al protective coatings not only do not deteriorate the magnetic properties of NdFeB, but contribute to their slight increase.

  16. AlN/Al dual protective coatings on NdFeB by DC magnetron sputtering

    International Nuclear Information System (INIS)

    Li Jinlong; Mao Shoudong; Sun Kefei; Li Xiaomin; Song Zhenlun

    2009-01-01

    AlN/Al dual protective coatings were prepared on NdFeB by DC magnetron sputtering in a home-made industrial apparatus. Comparing with Al coating, AlN/Al coatings have a denser structure of an outmost AlN amorphous layer following an inner Al columnar crystal layer. The coatings and NdFeB substrate combine well, and moreover, there is occurrence of metallurgy bonding in the interface layer. Both Al and AlN/Al coatings have a good protective ability to NdFeB. Especially, the corrosion resistance of AlN/Al coated NdFeB is improved largely. AlN/Al and Al protective coatings not only do not deteriorate the magnetic properties of NdFeB, but contribute to their slight increase.

  17. Sputter-Deposited Oxides for Interface Passivation of CdTe Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Kephart, Jason M.; Kindvall, Anna; Williams, Desiree; Kuciauskas, Darius; Dippo, Pat; Munshi, Amit; Sampath, W. S.

    2018-03-01

    Commercial CdTe PV modules have polycrystalline thin films deposited on glass, and devices made in this format have exceeded 22% efficiency. Devices made by the authors with a magnesium zinc oxide window layer and tellurium back contact have achieved efficiency over 18%, but these cells still suffer from an open-circuit voltage far below ideal values. Oxide passivation layers made by sputter deposition have the potential to increase voltage by reducing interface recombination. CdTe devices with these passivation layers were studied with photoluminescence (PL) emission spectroscopy and time-resolved photoluminescence (TRPL) to detect an increase in minority carrier lifetime. Because these oxide materials exhibit barriers to carrier collection, micropatterning was used to expose small point contacts while still allowing interface passivation. TRPL decay lifetimes have been greatly enhanced for thin polycrystalline absorber films with interface passivation. Device performance was measured and current collection was mapped spatially by light-beam-induced current.

  18. Structure of anodized Al–Zr sputter deposited coatings and effect on optical appearance

    DEFF Research Database (Denmark)

    Gudla, Visweswara Chakravarthy; Canulescu, Stela; Shabadi, Rajashekhara

    2014-01-01

    The mechanism of interaction of light with the microstructure of anodized layer giving specific optical appearance is investigated using Al–Zr sputter deposited coating as a model system on an AA6060 substrate. Differences in the oxidative nature of various microstructural components result...... in the evolution of typical features in the anodized layer, which are investigated as a function of microstructure and correlated with its optical appearance. The Zr concentration in the coating was varied from 6 wt.% to 23 wt.%. Heat treatment of the coated samples was carried out at 550°C for 4 h in order...... to evolve Al–Zr based second phase precipitates in the microstructure. Anodizing was performed using 20 wt.% sulphuric acidat 18°C with an intention to study the effect of anodizing on the Al–Zr based precipitates in the coating.Detailed microstructural characterization of the coating and anodized layer...

  19. Studies on ion scattering and sputtering processes relevant to ion beam sputter deposition of multicomponent thin films

    International Nuclear Information System (INIS)

    Auciello, O.; Ameen, M.S.; Kingon, A.I.

    1989-01-01

    Results from computer simulation and experiments on ion scattering and sputtering processes in ion beam sputter deposition of high Tc superconducting and ferroelectric thin films are presented. It is demonstrated that scattering of neutralized ions from the targets can result in undesirable erosion of, and inert gas incorporation in, the growing films, depending on the ion/target atom ass ratio and ion beam angle of incidence/target/substrate geometry. The studies indicate that sputtering Kr + or Xe + ions is preferable to the most commonly used Ar + ions, since the undesirable phenomena mentioned above are minimized for the first two ions. These results are used to determine optimum sputter deposition geometry and ion beam parameters for growing multicomponent oxide thin films by ion beam sputter-deposition. 10 refs., 5 figs

  20. Very thick mixture oxide ion beam sputtering films for investigation of nonlinear material properties

    Science.gov (United States)

    Steinecke, Morten; Kiedrowski, Kevin; Jupé, Marco; Ristau, Detlev

    2017-11-01

    Currently, optical coating technology is facing a multitude of new challenges. Some of the new requirements are addressed to the spectral behavior of complex coatings, but in addition, the power handling capabilities gain in importance. Often, both demands are combined in the same component, for example in chirped mirrors for ultra-short pulse applications. The consequent demands on the accuracy of the layer thicknesses and the stability of the refractive indices require a deposition by sputtering processes. For high end components, Ion Beam Sputtering (IBS) is often the method of choice. Utilizing the Co-sputtering technique, IBS additionally allows a higher flexibility in the possible coating materials by mixing two pure oxides into one ternary composite material. These composite materials are also advantageous for researching third order nonlinear effects, which can limit the functionality of optics at high powers. The layer thicknesses required for this fundamental research often exceed 100 µm, which therefore makes low stress and absorption in the layer materials mandatory. A reduction of these decisive properties can be achieved by a thermal treatment of the sample. Usually, this is performed by a post-deposition annealing. Alternatively, the coating temperature can be increased. This is rarely done for IBS processes, but it can be assumed, that the effect is comparable to that of ex-situ annealing. In this work, different ternary mixtures of Al2O3/SiO2, HfO2/Al2O3 as well as Nb2O5/Al2O3 were investigated for their layer stress and absorption, applying both, in-situ temperature treatment as well as post manufacturing annealing. It is observed that suitable thermal treatment as well as material composition can significantly reduce layer stress and absorption in the deposited layer. This enabled the manufacturing of layers with thicknesses of over 180 µm as well as the measurement of nonlinear properties of the deposited materials. Contribution to the topical

  1. Physical and chemical characterization of Ag-doped Ti coatings produced by magnetron sputtering of modular targets

    International Nuclear Information System (INIS)

    Schmitz, Tobias; Warmuth, Franziska; Werner, Ewald; Hertl, Cornelia; Groll, Jürgen; Gbureck, Uwe; Moseke, Claus

    2014-01-01

    Silver-doped Ti films were produced using a single magnetron sputtering source equipped with a titanium target containing implemented silver modules under variation of bias voltage and substrate temperature. The Ti(Ag) films were characterized regarding their morphology, contact angle, phase composition, silver content and distribution as well as the elution of Ag + ions into cell media. SEM and AFM pictures showed that substrate heating during film deposition supported the formation of even and dense surface layers with small roughness values, an effect that could even be enforced, when a substrate bias voltage was applied instead. The deposition of both Ti and Ag was confirmed by X-ray diffraction. ICP-MS and EDX showed a clear correlation between the applied sputtering parameters and the silver content of the coatings. Surface-sensitive XPS measurements revealed that higher substrate temperatures led to an accumulation of Ag in the near-surface region, while the application of a bias voltage had the opposite effect. Additional elution measurements using ICP-MS showed that the release kinetics depended on the amount of silver located at the film surface and hence could be tailored by variation of the sputter parameters. - Highlights: • Modular targets were used to deposit Ti(Ag) films. • Ag-content is adjustable by bias voltage, sputtering power and substrate temperature. • Coating parameters significantly change film morphology and roughness. • A critical parameter for Ag release is the fraction of silver on the film surface

  2. The optical properties and applications of AlN thin films prepared by a helicon sputtering system

    CERN Document Server

    Chiu, W Y; Kao, H L; Jeng, E S; Chen, J S; Jaing, C C

    2002-01-01

    AlN thin films were grown on SiO sub 2 /Si and quartz substrates using a helicon sputtering system. The dependence of film quality on growth parameters, such as total sputtering pressure, substrate temperature, and nitrogen concentration has been studied. There is a good correlation of thin film crystallinity addressed by x-ray diffraction (XRD) and spectroscopic ellipsometer. The optimized films exhibit highly oriented, with only (002) peak shown in a theta-2 theta scan XRD pattern, and extremely smooth surface with rms roughness of 2 Aa. The extinction coefficient of the film was 4x10 sup - sup 4 , which is lower than that of AlN films grown by conventional sputtering. Double-layer antireflection (DLAR) coating using AlN and Al sub 3 O sub 3 grown on quartz has been demonstrated. The transmittance of DLAR was high as 96% compared to 93% of bare substrates with the measurement error less than 0.2%. AlN films prepared by Helicon sputtering thus are potential for optical application.

  3. Discharge Physics of High Power Impulse Magnetron Sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2010-10-13

    High power impulse magnetron sputtering (HIPIMS) is pulsed sputtering where the peak power exceeds the time-averaged power by typically two orders of magnitude. The peak power density, averaged over the target area, can reach or exceed 107 W/m2, leading to plasma conditions that make ionization of the sputtered atoms very likely. A brief review of HIPIMS operation is given in a tutorial manner, illustrated by some original data related to the self-sputtering of niobium in argon and krypton. Emphasis is put on the current-voltage-time relationships near the threshold of self-sputtering runaway. The great variety of current pulse shapes delivers clues on the very strong gas rarefaction, self-sputtering runaway conditions, and the stopping of runaway due to the evolution of atom ionization and ion return probabilities as the gas plasma is replaced by metal plasma. The discussions are completed by considering instabilities and the special case of ?gasless? self-sputtering.

  4. High rate reactive sputtering in an opposed cathode closed-field unbalanced magnetron sputtering system

    Science.gov (United States)

    Sproul, William D.; Rudnik, Paul J.; Graham, Michael E.; Rohde, Suzanne L.

    1990-01-01

    Attention is given to an opposed cathode sputtering system constructed with the ability to coat parts with a size up to 15 cm in diameter and 30 cm in length. Initial trials with this system revealed very low substrate bias currents. When the AlNiCo magnets in the two opposed cathodes were arranged in a mirrored configuration, the plasma density at the substrate was low, and the substrate bias current density was less than 1 mA/sq cm. If the magnets were arranged in a closed-field configuration where the field lines from one set of magnets were coupled with the other set, the substrate bias current density was as high as 5.7 mA/sq cm when NdFeB magnets were used. In the closed-field configuration, the substrate bias current density was related to the magnetic field strength between the two cathodes and to the sputtering pressure. Hard well-adhered TiN coatings were reactively sputtered in the opposed cathode system in the closed-field configuration, but the mirrored configuration produced films with poor adhesion because of etching problems and low plasma density at the substrate.

  5. Sputtered protective coatings for die casting dies

    Science.gov (United States)

    Mirtich, M. J.; Nieh, C.-Y.; Wallace, J. F.

    1981-01-01

    Three experimental research designs investigating candidate materials and processes involved in protective die surface coating procedures by sputter deposition, using ion beam technologies, are discussed. Various pre-test results show that none of the coatings remained completely intact for 15,000 test cycles. The longest lifetime was observed for coatings such as tungsten, platinum, and molybdenum which reduced thermal fatigue, but exhibited oxidation and suppressed crack initiation only as long as the coating did not fracture. Final test results confirmed earlier findings and coatings with Pt and W proved to be the candidate materials to be used on a die surface to increase die life. In the W-coated specimens, which remained intact on the surface after thermal fatigue testing, no oxidation was found under the coating, although a few cracks formed on the surface where the coating broke down. Further research is planned.

  6. Magnetostrictive thin films prepared by RF sputtering

    International Nuclear Information System (INIS)

    Carabias, I.; Martinez, A.; Garcia, M.A.; Pina, E.; Gonzalez, J.M.; Hernando, A.; Crespo, P.

    2005-01-01

    Fe 80 B 20 thin films have been prepared by ion beam sputtering magnetron on room temperature. The films were fabricated on different substrates to compare the different magnetic and structural properties. In particular the growth of films on flexible substrates (PDMS, Kapton) has been studied to allow a simple integration of the system in miniaturized magnetostrictive devices. X-ray diffraction patterns indicate that films are mainly amorphous although the presence of some Fe nanoparticles cannot be ruled out. The coercive field of thin films ranges between 15 and 35 Oe, depending on substrate. Magnetostriction measurements indicate the strong dependence of the saturation magnetostriction with the substrate. Samples on flexible substrates exhibit a better performance than samples deposited onto glass substrates

  7. Structure, properties and wear behaviour of multilayer coatings consisting of metallic and covalent hard materials, prepared by magnetron sputtering

    International Nuclear Information System (INIS)

    Schier, V.

    1995-12-01

    Novel multilayer coatings with metallic and covalent layer materials were prepared by magnetron sputtering and characterised concerning structure, properties and application behaviour. At first single layer coatings were deposited for the determination of the material properties. To evaluate relations between structure and properties of the multilayer coatings, different multilayer concepts were realised: - coatings consisting of at most 7 layers of metallic hard materials, - 100-layer coatings consisting of metallic and covalent hard materials, - TiN-TiC multilayer coatings with different numbers of layers (between 10 and 1000), - 150-layer coatings, based on TiN-TiC multilayers, with thin ( 4 C, AlN, SiC, a:C, Si 3 N 4 , SiAlON). X-rays and electron microscopic analysis indicate in spite of nonstoichiometric compositions single phase crystalline structures for nonreactively and reactively sputtered metastable single layer Ti(B,C)-, Ti(B,N)- and Ti(B,C,N)-coatings. These single layer coatings show excellent mechanical properties (e.g. hardness values up to 6000 HV0,05), caused by lattice stresses as well as by atomic bonding conditions similar to those in c:BN and B 4 C. The good tribological properties shown in pin-on-disk-tests can be attributed to the very high hardness of the coatings. The coatings consisting of at most 7 layers of metallic hard materials show good results mainly for the cutting of steel Ck45, due to the improved mechanical properties (e.g. hardness, toughness) of the multilayers compared to the single layer coatings. This improvement is caused by inserting the hard layer materials and the coherent reinforcement of the coatings. (orig.)

  8. Ultrasound guided supraclavicular block.

    LENUS (Irish Health Repository)

    Hanumanthaiah, Deepak

    2013-09-01

    Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance.

  9. Stoichiometric carbon nitride synthesized by ion beam sputtering and post nitrogen ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Valizadeh, R.; Colligon, J.S. [Salford Univ. (United Kingdom). DMM Institute; Katardiev, I.V. [Uppsala Univ. (Sweden). Angstrom Laboratory; Faunce, C.A.; Donnelly, S.E. [Salford Univ. (United Kingdom). Science Institute

    1998-06-01

    Full text: Carbon nitride films have been deposited on Si (100) by ion beam sputtering a vitreous graphite target with nitrogen and argon ions with and without concurrent N2 ion bombardment at room temperature. The sputtering beam energy was 1000 eV and the assisted beam energy was 300 eV with ion / atom arrival ratio ranging from 0.5 to 5. The carbon nitride films were deposited both as single layer directly on silicon substrate and as multilayer between two layers of stoichiometric amorphous silicon nitride and polycrystalline titanium nitride. The deposited films were implanted ex-situ with 30 keV nitrogen ions with various doses ranging from 1E17 to 4E17 ions.cm{sup -2} and 2 GeV xenon ion with a dose of 1E12 ions.cm{sup -2} . The nitrogen concentration of the films was measured with Rutherford Backscattering (RBS), Secondary Neutral Mass Spectrometry (SNMS) and Parallel Electron Energy Loss Spectroscopy (PEELS). The nitrogen concentration for as deposited sample was 34 at% and stoichiometric carbon nitride C{sub 3}N{sub 4} was achieved by post nitrogen implantation of the multi-layered films. Post bombardment of single layer carbon nitride films lead to reduction in the total nitrogen concentration. Carbon K edge structure obtained from PEELS analysis suggested that the amorphous C{sub 3}N{sub 4} matrix was predominantly sp{sup 2} bonded. This was confirmed by Fourier Transforrn Infra-Red Spectroscopy (FTIR) analysis of the single CN layer which showed the nitrogen was mostly bonded with carbon in nitrile (C{identical_to}N) and imine (C=N) groups. The microstructure of the film was determined by Transmission Electron Microscopy (TEM) which indicated that the films were amorphous.

  10. Origin of the improved stability under negative gate-bias illumination stress in various sputtering power fabricated ZnSnO TFTs

    Science.gov (United States)

    Huang, Chuan-Xin; Li, Jun; Fu, Yi-Zhou; Zhang, Jian-Hua; Jiang, Xue-Yin; Zhang, Zhi-Lin

    2015-12-01

    In this work, we report the influence of ZnSnO channel layer sputtering power in the stability of ZnSnO TFTs under negative gate-bias illumination stress (NBIS). The origin of threshold voltage shift results from combined effect of two factors between the little defect-induced trap densities originated from oxygen vacancies and better channel-insulator interface. The kinetic energy of the ions at a proper rf sputtering power is responsible for less defect-induced trap density and better channel-insulator interface. Therefore, the ZnSnO TFT fabricated at 75 W sputtering power shows a better NBIS stability. In addition, the trap density is extracted by temperature-dependent field-effect measurements and it is consistent with the change of stability under NBIS and thermal stress.

  11. Applications of ZnO:Al deposited by RF sputtering to InN low-cost technology

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, S. [Departamento de Energias Renovables, Energia Solar Fotovoltaica, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Madrid (Spain); Naranjo, F.B.; Valdueza-Felip, S. [Grupo de Ingenieria Fotonica, Departamento de Electronica, Escuela Politecnica Superior, Universidad de Alcala Campus Universitario, Madrid (Spain); Abril, O. de [ISOM y Departamento de Fisica Aplicada, Escuela Tecnica Superior de Ingenieros de Telecomunicacion, Universidad Politenica de Madrid (Spain)

    2010-07-15

    InN/ZnO:Al heterostructures deposited at low temperature on different substrates by radio-frequency sputtering were studied. Using ZnO:Al as buffer layer, an improvement in the InN structural properties was achieved. Evaluating ZnO:Al as contact on InN, an Ohmic behaviour for the as-deposited layer on InN was achieved. A specific contact resistance of 2 {omega} cm{sup 2} was measured without any post-deposition treatment. These properties could result very promising for optoelectronic device applications. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  12. Effect of sputtered lanthanum hexaboride film thickness on field emission from metallic knife edge cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Kirley, M. P.; Novakovic, B.; Sule, N.; Weber, M. J.; Knezevic, I.; Booske, J. H. [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

    2012-03-15

    We report experiments and analysis of field emission from metallic knife-edge cathodes, which are sputter-coated with thin films of lanthanum hexaboride (LaB{sub 6}), a low-work function material. The emission current is found to depend sensitively on the thickness of the LaB{sub 6} layer. We find that films thinner than 10 nm greatly enhance the emitted current. However, cathodes coated with a thicker layer of LaB{sub 6} are observed to emit less current than the uncoated metallic cathode. This result is unexpected due to the higher work function of the bare metal cathode. We show, based on numerical calculation of the electrostatic potential throughout the structure, that the external (LaB{sub 6}/vacuum) barrier is reduced with respect to uncoated samples for both thin and thick coatings. However, this behavior is not exhibited at the internal (metal/LaB{sub 6}) barrier. In thinly coated samples, electrons tunnel efficiently through both the internal and external barrier, resulting in current enhancement with respect to the uncoated case. In contrast, the thick internal barrier in thickly coated samples suppresses current below the value for uncoated samples in spite of the lowered external barrier. We argue that this coating thickness variation stems from a relatively low (no higher than 10{sup 18} cm{sup -3}) free carrier density in the sputtered polycrystalline LaB{sub 6}.

  13. Antibacterial properties of palladium nanostructures sputtered on polyethylene naphthalate

    Czech Academy of Sciences Publication Activity Database

    Polívková, M.; Válová, M.; Siegel, J.; Rimpelová, S.; Hubáček, Tomáš; Lyutakov, O.; Švorčík, V.

    2015-01-01

    Roč. 5, č. 90 (2015), s. 73767-73774 ISSN 2046-2069 Institutional support: RVO:60077344 Keywords : polymer * palladium sputtering * annealing * nanostructure * antibacterial effect Subject RIV: JJ - Other Materials Impact factor: 3.289, year: 2015

  14. Sputter-Resistant Materials for Electric Propulsion, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase 2 project shall develop sputter-resistant materials for use in electric propulsion test facilities and for plume shields on spacecraft using electric...

  15. Development of ion beam sputtering techniques for actinide target preparation

    International Nuclear Information System (INIS)

    Aaron, W.S.; Zevenbergen, L.A.; Adair, H.L.

    1985-01-01

    Ion beam sputtering is a routine method for the preparation of thin films used as targets because it allows the use of minimum quantity of starting material, and losses are much lower than most other vacuum deposition techniques. Work is underway in the Isotope Research Materials Laboratory (IRML) at ORNL to develop the techniques that will make the preparation of actinide targets up to 100 μg/cm 2 by ion beam sputtering a routinely available service from IRML. The preparation of the actinide material in a form suitable for sputtering is a key to this technique, as is designing a sputtering system that allows the flexibility required for custom-ordered target production. At present, development work is being conducted on low-activity in a bench-top system. The system will then be installed in a hood or glove box approved for radioactive materials handling where processing of radium, actinium, and plutonium isotopes among others will be performed. (orig.)

  16. Sputter deposition of metallic thin film and directpatterning

    Energy Technology Data Exchange (ETDEWEB)

    Ji, L.; Chen, Y.; Jiang, X.; Ji, Q.; Leung, K.-N.

    2005-09-09

    A compact apparatus is developed for deposition of metal thin film. The system employs an RF discharge plasma source with a straight RF antenna, which is made of or covered with deposition material, serving as sputtering target at the same time. The average deposition rate of copper thin film is as high as 450nm/min. By properly allocating the metal materials on the sputtering antenna, mixture deposition of multiple metal species is achieved. Using an ion beam imprinting scheme also taking advantage of ion beam focusing technique, two different schemes of direct patterning deposition process are developed: direct depositing patterned metallic thin film and resistless ion beam sputter patterning. Preliminary experiments have demonstrated direct pattern transfer from a template with feature size of micro scale; patterns with more than 10x reduction are achieved by sputtering patterning method.

  17. CO2 gas sensitivity of sputtered zinc oxide thin films

    Indian Academy of Sciences (India)

    TECS

    Abstract. For the first time, sputtered zinc oxide (ZnO) thin films have been used as a CO2 gas sensor. Zinc oxide thin films have been synthesized using reactive d.c. sputtering method for gas sensor applications, in the deposition temperature range from 130–153°C at a chamber pressure of 8⋅5 mbar for 18 h. Argon and ...

  18. Sputtering of Thick Deuterium Films by KeV Electrons

    DEFF Research Database (Denmark)

    Thestrup Nielsen, Birgitte; Svendsen, Winnie Edith; Schou, Jørgen

    1994-01-01

    Sputtering of thick films of solid deuterium up to several μm by keV electrons is reported for the first time. The sputtering yield increases within a narrow range of thicknesses around 1.6 μm by about 2 orders of magnitude for 1.5 keV electrons. A similar behavior has not been observed for ion...... bombardment. The yield enhancement is accompanied by an increasing electron accumulation in the film....

  19. Deposition and characterization of titania-silica optical multilayers by asymmetric bipolar pulsed dc sputtering of oxide targets

    International Nuclear Information System (INIS)

    Sagdeo, P R; Shinde, D D; Misal, J S; Kamble, N M; Tokas, R B; Biswas, A; Poswal, A K; Thakur, S; Bhattacharyya, D; Sahoo, N K; Sabharwal, S C

    2010-01-01

    Titania-silica (TiO 2 /SiO 2 ) optical multilayer structures have been conventionally deposited by reactive sputtering of metallic targets. In order to overcome the problems of arcing, target poisoning and low deposition rates encountered there, the application of oxide targets was investigated in this work with asymmetric bipolar pulsed dc magnetron sputtering. In order to evaluate the usefulness of this deposition methodology, an electric field optimized Fabry Perot mirror for He-Cd laser (λ = 441.6 nm) spectroscopy was deposited and characterized. For comparison, this mirror was also deposited by the reactive electron beam (EB) evaporation technique. The mirrors developed by the two complementary techniques were investigated for their microstructural and optical reflection properties invoking atomic force microscopy, ellipsometry, grazing incidence reflectometry and spectrophotometry. From these measurements the layer geometry, optical constants, mass density, topography, surface and interface roughness and disorder parameters were evaluated. The microstructural properties and spectral functional characteristics of the pulsed dc sputtered multilayer mirror were found to be distinctively superior to the EB deposited mirror. The knowledge gathered during this study has been utilized to develop a 21-layer high-pass edge filter for radio photoluminescence dosimetry.

  20. Application of torsion vacuum microbalance to sputtering yield measurement

    International Nuclear Information System (INIS)

    Akaishi, Kenya; Miyahara, Akira; Sukenobu, Satoru; Komizo, Mutsuo.

    1977-01-01

    The torsion vacuum microbalance technique useful for the determination of the sputtering yield of wall materials for fusion reactors was developed. In order to measure the rate of weight change of the samples during sputtering continuously, it is very important to keep the null point drift of the microbalance as small as possible. The deflection angle of the balance beam was detected and amplified by optical lever, and was transformed to electrical output by linear photopotentiometer. The null point drift wave mainly caused by temperature change in the laboratory, which induced relative displacement by thermal expansion between the balance system and the optical measuring system. The drift was reduced less than the equivalent weight of 4 x 10 -7 g/hr when the balance system wosset in the thermostat kept at 20 +- 0.5 0 C. The sensitivity of the balance was 8.3 x 10 -7 g/mV. The microbalance technique developed was applied to the measurement of sputtering yield of Cu by Ar + . The measurement was carried out with Ar + ion energy of 0.2 -- 2 keV, beam current of 0.5 -- 1.5 μA, and sputtering time of 2 hrs. The initial weight of Cu sample was 0.4g (15 mm x 15 mm sheet) and the sample temperature during sputtering was about 120 0 C. The sputtering yields obtained show good agreement with the results reported by Wehner et al. (auth.)

  1. Sputter-grown Si quantum dot nanostructures for tandem solar cells

    Science.gov (United States)

    Huang, Shujuan; Conibeer, Gavin

    2013-01-01

    Silicon quantum dot (QD)-based ‘all-silicon’ tandem solar cells have emerged as a promising third generation photovoltaic approach to realize high-efficiency and cost effective solar cells. This approach exploits the quantum confinement effect of silicon QDs embedded in a dielectric matrix to engineer the effective electronic bandgap of a solar cell material. Research work in our group has shown that such a Si QD solar cell can be fabricated by co-sputtering of thin layers of Si-rich dielectric sandwiched between stoichiometric dielectric layers which crystallize to form Si QDs of uniform size on annealing. The Si-richness in the Si-rich layer plays an important role in formation of uniform size and shape. The matrix and barrier layer materials also affect the formation of Si QDs. The bandgap tunability of such Si QD superlattice structures has been clearly demonstrated by photoluminescence and electroluminescence measurements. Doping of Si QD layers has been achieved by impurity incorporation of P, Sb or B in the Si-rich layers. Strong evidence of effective doping has been demonstrated from the enhanced conductivity, from the dopant concentrations extracted from MOS structures and from the formation of rectifying p-n junctions which give an open circuit voltage (Voc) of 492 mV. The doping mechanism is more likely to be modified interface doping rather than direct doping to the Si QDs.

  2. Self-assembled metal nano-multilayered film prepared by co-sputtering method

    Science.gov (United States)

    Xie, Tianle; Fu, Licai; Qin, Wen; Zhu, Jiajun; Yang, Wulin; Li, Deyi; Zhou, Lingping

    2018-03-01

    Nano-multilayered film is usually prepared by the arrangement deposition of different materials. In this paper, a self-assembled nano-multilayered film was deposited by simultaneous sputtering of Cu and W. The Cu/W nano-multilayered film was accumulated by W-rich layer and Cu-rich layer. Smooth interfaces with consecutive composition variation and semi-coherent even coherent relationship were identified, indicating that a spinodal-like structure with a modulation wavelength of about 20 nm formed during co-deposition process. The participation of diffusion barrier element, such as W, is believed the essential to obtain the nano-multilayered structure besides the technological parameters.

  3. Anodisation of sputter deposited aluminium–titanium coatings: Effect of microstructure on optical characteristics

    DEFF Research Database (Denmark)

    Aggerbeck, Martin; Junker-Holst, Andreas; Vestergaard Nielsen, Daniel

    2014-01-01

    Magnetron sputtered coatings of aluminium containing up to 18 wt.% titanium were deposited on aluminium substrates to study the effect of microstructure on the optical appearance of the anodised layer. The microstructure and morphology were studied using transmission electron microscopy (TEM), X......-ray diffraction (XRD), and glow discharge optical emission spectroscopy (GDOES), while the optical appearance was investigated using photospectrometry. The microstructure of the coatings was varied by heat treatment, resulting in the precipitation of Al3Ti phases. The reflectance of the anodised surfaces...... decreasedwith titaniumcontent in the as-deposited, and heat-treated states, and after anodisation of the as-deposited coatings. Specimens turned grey or blackwhen anodising after heat treatment. Partially anodised Al3Ti phaseswere found in the anodised layer, and the interface between substrate and anodised...

  4. Highly-enhanced reflow characteristics of sputter deposited Cu interconnections of large scale integrated devices by optimizing sputtering conditions

    Science.gov (United States)

    Onishi, Takashi; Mizuno, Masao; Yoshikawa, Tetsuya; Munemasa, Jun; Mizuno, Masataka; Kihara, Teruo; Araki, Hideki; Shirai, Yasuharu

    2013-07-01

    Improving the reflow characteristics of sputtered Cu films was attempted by optimizing the sputtering conditions. The reflow characteristics of films deposited under various sputtering conditions were evaluated by measuring their filling level in via holes. It was found that the reflow characteristics of the Cu films are strongly influenced by the deposition parameters. Deposition at low temperatures and the addition of H2 or N2 to the Ar sputtering gas had a significant influence on the reflow characteristics. Imperfections in the Cu films before and after the high-temperature, high-pressure treatments were investigated by positron annihilation spectroscopy. The results showed that low temperature and the addition of H2 or N2 led to films containing a large number of mono-vacancies, which accelerate atomic diffusion creep and dislocation core diffusion creep, improving the reflow characteristics of the Cu films.

  5. Homogeneous bilateral block shifts

    Indian Academy of Sciences (India)

    Douglas class were classified in [3]; they are unilateral block shifts of arbitrary block size (i.e. dim H(n) can be anything). However, no examples of irreducible homogeneous bilateral block shifts of block size larger than 1 were known until now.

  6. Plasma potential of a moving ionization zone in DC magnetron sputtering

    Science.gov (United States)

    Panjan, Matjaž; Anders, André

    2017-02-01

    Using movable emissive and floating probes, we determined the plasma and floating potentials of an ionization zone (spoke) in a direct current magnetron sputtering discharge. Measurements were recorded in a space and time resolved manner, which allowed us to make a three-dimensional representation of the plasma potential. From this information we could derive the related electric field, space charge, and the related spatial distribution of electron heating. The data reveal the existence of strong electric fields parallel and perpendicular to the target surface. The largest E-fields result from a double layer structure at the leading edge of the ionization zone. We suggest that the double layer plays a crucial role in the energization of electrons since electrons can gain several 10 eV of energy when crossing the double layer. We find sustained coupling between the potential structure, electron heating, and excitation and ionization processes as electrons drift over the magnetron target. The brightest region of an ionization zone is present right after the potential jump, where drifting electrons arrive and where most local electron heating occurs. The ionization zone intensity decays as electrons continue to drift in the Ez × B direction, losing energy by inelastic collisions; electrons become energized again as they cross the potential jump. This results in the elongated, arrowhead-like shape of the ionization zone. The ionization zone moves in the -Ez × B direction from which the to-be-heated electrons arrive and into which the heating region expands; the zone motion is dictated by the force of the local electric field on the ions at the leading edge of the ionization zone. We hypothesize that electron heating caused by the potential jump and physical processes associated with the double layer also apply to magnetrons at higher discharge power, including high power impulse magnetron sputtering.

  7. Surface functionalization of nanostructured LaB{sub 6}-coated Poly Trilobal fabric by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yan, E-mail: wuyanchn@hotmail.com [Mechanical and Electrical Engineering Branch, Jiaxing Nanyang Polytechnic Institute, Jiaxing 314003 (China); Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China); Zhang, Lin, E-mail: zhanglin2007@sdu.edu.cn [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China); Min, Guanghui, E-mail: ghmin@sdu.edu.cn [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China); Yu, Huashun; Gao, Binghuan; Liu, Huihui; Xing, Shilong; Pang, Tao [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China)

    2016-10-30

    Highlights: • Nanostructured LaB{sub 6} films were deposited on flexible textile substrates by dc magnetron sputtering. • The pronounced influence of the working pressure on the morphologies and optical properties of LaB{sub 6} films has been revealed. • The concept of Ultraviolet Protection Factor (UPF) was employed and LaB{sub 6}-coated PET textiles with ultraviolet protection ability were obtained. - Abstract: Nanostructured LaB{sub 6} films were deposited on flexible Poly Trilobal substrates (PET textiles) through direct current magnetron sputtering in order to broaden its applications and realize surface functionalization of polyester fabrics. Characterizations and performances were investigated by employing a scanning electron microscope (SEM), Fourier transformation infrared spectroscopy (FT-IR) and ultraviolet-visible (UV–vis) spectrophotometer. Ultraviolet Protection Factor (UPF) conducted by the integral conversion was employed to measure the ultraviolet protection ability. As expected, the growth of LaB{sub 6} film depending on the pressure variation enhanced UV-blocking ability (UPF rating at 30.17) and absorption intensity of the textiles.

  8. Analyzing block placement errors in SADP patterning

    Science.gov (United States)

    Kobayashi, Shinji; Okada, Soichiro; Shimura, Satoru; Nafus, Kathleen; Fonseca, Carlos; Demand, Marc; Biesemans, Serge; Versluijs, Janko; Ercken, Monique; Foubert, Philippe; Miyazaki, Shinobu

    2016-03-01

    We discuss edge placement errors (EPE) for multi-patterning of Mx critical layers using ArF lithography. Specific focus is placed on the block formation part of the process. While plenty of literature characterization data exist on spacer formation, only limited published data is available on block processes. We analyze the accuracy of placing blocks relative to narrow spacers. Many publications calculate EPE assuming Gaussian distributions for key process variations contributing to EPE. For practical reasons, each contributor is measured on dedicated test structures. In this work, we complement such analysis and directly measure the EPE in product. We perform high density sampling of blocks using CDSEM images and analyze all feature edges of interest. We find that block placement errors can be very different depending on their local design context. Specifically we report on 2 block populations (further called block A and B) which have a 4x different standard deviation. We attribute this to differences in local topography (spacer shape) and interaction with the plasma-etch process design. Block A (on top of the `core space' S1) has excellent EPE uniformity of ~1 nm while block B (on top of `gap space' S2) has degraded EPE control of ~4 nm. Finally, we suggest that the SOC etch process is at the origin on positioning blocks accurately on slim spacers, helping the manufacturability of spacer-based patterning techniques, and helping its extension toward the 5nm node.

  9. Thick beryllium coatings by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H; Nikroo, A; Youngblood, K; Moreno, K; Wu, D; Fuller, T; Alford, C; Hayes, J; Detor, A; Wong, M; Hamza, A; van Buuren, T; Chason, E

    2011-04-14

    Thick (>150 {micro}m) beryllium coatings are studied as an ablator material of interest for fusion fuel capsules for the National Ignition Facility (NIF). As an added complication, the coatings are deposited on mm-scale spherical substrates, as opposed to flats. DC magnetron sputtering is used because of the relative controllability of the processing temperature and energy of the deposits. We used ultra small angle x-ray spectroscopy (USAXS) to characterize the void fraction and distribution along the spherical surface. We investigated the void structure using a combination focused ion beam (FIB) and scanning electron microscope (SEM), along with transmission electron microscopy (TEM). Our results show a few volume percent of voids and a typical void diameter of less than two hundred nanometers. Understanding how the stresses in the deposited material develop with thickness is important so that we can minimize film cracking and delamination. To that end, an in-situ multiple optical beam stress sensor (MOSS) was used to measure the stress behavior of thick Beryllium coatings on flat substrates as the material was being deposited. We will show how the film stress saturates with thickness and changes with pressure.

  10. Pressureless Bonding Using Sputtered Ag Thin Films

    Science.gov (United States)

    Oh, Chulmin; Nagao, Shijo; Suganuma, Katsuaki

    2014-12-01

    To improve the performance and reliability of power electronic devices, particularly those built around next-generation wide-bandgap semiconductors such as SiC and GaN, the bonding method used for packaging must change from soldering to solderless technology. Because traditional solders are problematic in the harsh operating conditions expected for emerging high-temperature power devices, we propose a new bonding method in this paper, namely a pressureless, low-temperature bonding process in air, using abnormal grain growth on sputtered Ag thin films to realize extremely high temperature resistance. To investigate the mechanisms of this bonding process, we characterized the microstructural changes in the Ag films over various bonding temperatures and times. We measured the bonding properties of the specimens by a die-shear strength test, as well as by x-ray diffraction measurements of the residual stress in the Ag films to show how the microstructural developments were essential to the bonding technology. Sound bonds with high die strength can be achieved only with abnormal grain growth at optimum bonding temperature and time. Pressureless bonding allows for production of reliable high-temperature power devices for a wide variety of industrial, energy, and environmental applications.

  11. Energy dissipation in intercalated carbon nanotube forests with metal layers

    Science.gov (United States)

    Vertically aligned carbon nanotube (CNT) forests were synthesized to study their quasi-static mechanical properties in a layered configuration with metallization. The top and bottom surfaces of CNT forests were metalized with Ag, Fe, and In using paste, sputtering, and thermal evaporation, respectiv...

  12. Morphology and N₂ Permeance of Sputtered Pd-Ag Ultra-Thin Film Membranes.

    Science.gov (United States)

    Fernandez, Ekain; Sanchez-Garcia, Jose Angel; Viviente, Jose Luis; van Sint Annaland, Martin; Gallucci, Fausto; Tanaka, David A Pacheco

    2016-02-10

    The influence of the temperature during the growth of Pd-Ag films by PVD magnetron sputtering onto polished silicon wafers was studied in order to avoid the effect of the support roughness on the layer growth. The surfaces of the Pd-Ag membrane films were analyzed by atomic force microscopy (AFM), and the results indicate an increase of the grain size from 120 to 250-270 nm and film surface roughness from 4-5 to 10-12 nm when increasing the temperature from around 360-510 K. After selecting the conditions for obtaining the smallest grain size onto silicon wafer, thin Pd-Ag (0.5-2-µm thick) films were deposited onto different types of porous supports to study the influence of the porous support, layer thickness and target power on the selective layer microstructure and membrane properties. The Pd-Ag layers deposited onto ZrO₂ 3-nm top layer supports (smallest pore size among all tested) present high N₂ permeance in the order of 10(-6) mol·m(-2)·s(-1)·Pa(-1) at room temperature.

  13. Morphology and N2 Permeance of Sputtered Pd-Ag Ultra-Thin Film Membranes

    Directory of Open Access Journals (Sweden)

    Ekain Fernandez

    2016-02-01

    Full Text Available The influence of the temperature during the growth of Pd-Ag films by PVD magnetron sputtering onto polished silicon wafers was studied in order to avoid the effect of the support roughness on the layer growth. The surfaces of the Pd-Ag membrane films were analyzed by atomic force microscopy (AFM, and the results indicate an increase of the grain size from 120 to 250–270 nm and film surface roughness from 4–5 to 10–12 nm when increasing the temperature from around 360–510 K. After selecting the conditions for obtaining the smallest grain size onto silicon wafer, thin Pd-Ag (0.5–2-µm thick films were deposited onto different types of porous supports to study the influence of the porous support, layer thickness and target power on the selective layer microstructure and membrane properties. The Pd-Ag layers deposited onto ZrO2 3-nm top layer supports (smallest pore size among all tested present high N2 permeance in the order of 10−6 mol·m−2·s−1·Pa−1 at room temperature.

  14. Superconducting structure with layers of niobium nitride and aluminum nitride

    Science.gov (United States)

    Murduck, J.M.; Lepetre, Y.J.; Schuller, I.K.; Ketterson, J.B.

    1989-07-04

    A superconducting structure is formed by depositing alternate layers of aluminum nitride and niobium nitride on a substrate. Deposition methods include dc magnetron reactive sputtering, rf magnetron reactive sputtering, thin-film diffusion, chemical vapor deposition, and ion-beam deposition. Structures have been built with layers of niobium nitride and aluminum nitride having thicknesses in a range of 20 to 350 Angstroms. Best results have been achieved with films of niobium nitride deposited to a thickness of approximately 70 Angstroms and aluminum nitride deposited to a thickness of approximately 20 Angstroms. Such films of niobium nitride separated by a single layer of aluminum nitride are useful in forming Josephson junctions. Structures of 30 or more alternating layers of niobium nitride and aluminum nitride are useful when deposited on fixed substrates or flexible strips to form bulk superconductors for carrying electric current. They are also adaptable as voltage-controlled microwave energy sources. 8 figs.

  15. The corrosion and passivity of sputtered Mg–Ti alloys

    International Nuclear Information System (INIS)

    Song, Guang-Ling; Unocic, Kinga A.; Meyer, Harry; Cakmak, Ercan; Brady, Michael P.; Gannon, Paul E.; Himmer, Phil; Andrews, Quinn

    2016-01-01

    Highlights: • A supersaturated single phase Mg–Ti alloy can be obtained by magnetron sputtering. • The anodic dissolution of Mg–Ti alloy is inhibited by Ti addition. • The alloy becomes passive when Ti content is high and the alloy has become Ti based. • The formation of a continuous thin passive film is responsible for the passivation of the alloy. - Abstract: This study explored the possibility of forming a “stainless” Mg–Ti alloy. The electrochemical behavior of magnetron-sputtered Mg–Ti alloys was measured in a NaCl solution, and the surface films on the alloys were examined by XPS, SEM and TEM. Increased corrosion resistance was observed with increased Ti content in the sputtered Mg–Ti alloys, but passive-like behavior was not reached until the Ti level (atomic %) was higher than the Mg level. The surface film that formed on sputtered Mg–Ti based alloys in NaCl solution was thick, discontinuous and non-protective, whereas a thin, continuous and protective Mg and Ti oxide film was formed on a sputtered Ti–Mg based alloy.

  16. Block copolymer structures in nano-pores

    Science.gov (United States)

    Pinna, Marco; Guo, Xiaohu; Zvelindovsky, Andrei

    2010-03-01

    We present results of coarse-grained computer modelling of block copolymer systems in cylindrical and spherical nanopores on Cell Dynamics Simulation. We study both cylindrical and spherical pores and systematically investigate structures formed by lamellar, cylinders and spherical block copolymer systems for various pore radii and affinity of block copolymer blocks to the pore walls. The obtained structures include: standing lamellae and cylinders, ``onions,'' cylinder ``knitting balls,'' ``golf-ball,'' layered spherical, ``virus''-like and mixed morphologies with T-junctions and U-type defects [1]. Kinetics of the structure formation and the differences with planar films are discussed. Our simulations suggest that novel porous nano-containers can be formed by confining block copolymers in pores of different geometries [1,2]. [4pt] [1] M. Pinna, X. Guo, A.V. Zvelindovsky, Polymer 49, 2797 (2008).[0pt] [2] M. Pinna, X. Guo, A.V. Zvelindovsky, J. Chem. Phys. 131, 214902 (2009).

  17. Alloying process of sputter-deposited Ti/Ni multilayer thin films

    International Nuclear Information System (INIS)

    Cho, H.; Kim, H.Y.; Miyazaki, S.

    2006-01-01

    Alloying process of a Ti/Ni multilayer thin film was investigated in detail by differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and transmission electron microscopy (TEM). The Ti/Ni multilayer thin film was prepared by depositing Ti and Ni layers alternately on a SiO 2 /Si substrate. The number of each metal layer was 100, and the total thickness was 3 μm. The alloy composition was determined as Ti-51 at.%Ni by electron probe micro analysis (EPMA). The DSC curve exhibited three exothermic peaks at 621, 680 and 701 K during heating the as-sputtered multilayer thin film. In order to investigate the alloying process, XRD and TEM observation was carried out for the specimens heated up to various temperatures with the heating rate same as the DSC measurement. The XRD profile of the as-sputtered film revealed only diffraction peaks of Ti and Ni. But reaction layers of 3 nm in thickness were observed at the interfaces of Ti and Ni layers in cross-sectional TEM images. The reaction layer was confirmed as an amorphous phase by the nano beam diffraction analysis. The XRD profiles exhibited that the intensity of Ti diffraction peak decreased in the specimen heat-treated above 600 K. The peak from Ni became broad and shifted to lower diffraction angle. The amorphous layer thickened up to 6 nm in the specimen heated up to 640 K. The diffraction peak corresponding to Ti-Ni B2 phase appeared and the peak from Ni disappeared for the specimen heated up to 675 K. The Ti-Ni B2 crystallized from the amorphous reaction layer. After further heating above the third exothermic peak, the intensity of the peak from the Ti-Ni B2 phase increased, the peak from Ti disappeared and the peaks corresponding to Ti 2 Ni appeared. The Ti 2 Ni phase was formed by the reaction of the Ti-Ni B2 and Ti

  18. Current Spreading Layer with High Transparency and Conductivity for near-ultraviolet light emitting diodes

    DEFF Research Database (Denmark)

    Lin, Li; Jensen, Flemming; Herstrøm, Berit

    Transparent conductive aluminum-doped zinc oxide (AZO) layer was deposited on GaN-based near-ultraviolet (NUV) light emitting epitaxial wafers as current spreading layer by a sputtering process. Efforts were made to improve the electrical properties of AZO in order to produce ohmic contact....

  19. Laser micromachined wax-covered plastic paper as both sputter deposition shadow masks and deep-ultraviolet patterning masks for polymethylmethacrylate-based microfluidic systems

    KAUST Repository

    Fan, Yiqiang

    2013-12-16

    We report a technically innovative method of fabricating masks for both deep-ultraviolet (UV) patterning and metal sputtering on polymethylmethacrylate (PMMA) for microfluidic systems. We used a CO2 laser system to cut the required patterns on wax-covered plastic paper; the laser-patterned wax paper will either work as a mask for deep-UV patterning or as a mask for metal sputtering. A microfluidic device was also fabricated to demonstrate the feasibility of this method. The device has two layers: the first layer is a 1-mm thick PMMA substrate that was patterned by deep-UV exposure to create microchannels. The mask used in this process was the laser-cut wax paper. The second layer, also a 1-mm thick PMMA layer, was gold sputtered with patterned wax paper as the shadow mask. These two pieces of PMMA were then bonded to form microchannels with exposed electrodes. This process is a simple and rapid method for creating integrated microfluidic systems that do not require cleanroom facilities.

  20. On the AlxGa1-xN/AlyGa1-yN/AlxGa1-xN (x>y) p-electron blocking layer to improve the hole injection for AlGaN based deep ultraviolet light-emitting diodes

    Science.gov (United States)

    Chu, Chunshuang; Tian, Kangkai; Fang, Mengqian; Zhang, Yonghui; Li, Luping; Bi, Wengang; Zhang, Zi-Hui

    2018-01-01

    This work proposes the [0001] oriented AlGaN-based deep ultraviolet (DUV) light-emitting diode (LED) possessing a specifically designed p-electron blocking layer (p-EBL) to achieve the high internal quantum efficiency. Both electrons and holes can be efficiently injected into the active region by adopting the Al0.60Ga0.40N/Al0.50Ga0.50N/Al0.60Ga0.40N structured p-EBL, in which a p-Al0.50Ga0.50N layer is embedded into the p-EBL. Moreover, the impact of different thicknesses for the p-Al0.50Ga0.50N insertion layer on the hole and electron injections has also been investigated. Compared with the DUV LED with the bulk p-Al0.60Ga0.40N as the EBL, the proposed LED architectures improve the light output power if the thickness of the p-Al0.50Ga0.50N insertion layer is properly designed.

  1. The Adobe Photoshop layers book

    CERN Document Server

    Lynch, Richard

    2011-01-01

    Layers are the building blocks for working in Photoshop. With the correct use of the Layers Tool, you can edit individual components of your images nondestructively to ensure that your end result is a combination of the best parts of your work. Despite how important it is for successful Photoshop work, the Layers Tool is one of the most often misused and misunderstood features within this powerful software program. This book will show you absolutely everything you need to know to work with layers, including how to use masks, blending, modes and layer management. You'll learn professional tech

  2. Infrared metamaterial by RF magnetron sputtered ZnO/Al:ZnO multilayers

    Science.gov (United States)

    Santiago, Kevin C.; Mundle, Rajeh; White, Curtis; Bahoura, Messaoud; Pradhan, Aswini K.

    2018-03-01

    Hyperbolic metamaterials create artificial anisotropy using metallic wires suspended in dielectric media or alternating layers of a metal and dielectric (Type I or Type II). In this study we fabricated ZnO/Al:ZnO (AZO) multilayers by the RF magnetron sputtering deposition technique. Our fabricated multilayers satisfy the requirements for a type II hyperbolic metamaterial. The optical response of individual AZO and ZnO films, as well as the multilayered film were investigated via UV-vis-IR transmittance and spectroscopic ellipsometry. The optical response of the multilayered system is calculated using the nonlocal-corrected Effective Medium Approximation (EMA). The spectroscopic ellipsometry data of the multilayered system was modeled using a uniaxial material model and EMA model. Both theoretical and experimental studies validate the fabricated multilayers undergo a hyperbolic transition at a wavelength of 2.2 μm. To our knowledge this is the first AZO/ZnO type II hyperbolic metamaterial system fabricated by magnetron sputtering deposition method.

  3. Characteristics of Cu films prepared using a magnetron sputter type negative ion source (MSNIS)

    Science.gov (United States)

    Paik, Namwoong

    2005-12-01

    Cu films have been deposited at room temperature using a magnetron sputter type negative ion source (MSNIS) at various conditions. By the principle of operation, the negative ion production probability is the function of the Cs flow rate in MSNIS. A set of films were deposited at different Cs flow rates and compared with normal-magnetron-sputtered films. The long-throw method was combined to MSNIS to increase the directionality and the negative ion arrival ratio. The film properties, such as resistivity, surface roughness, film structure, and step coverage on high aspect-ratio trench samples were obtained and analyzed using SEM, SIMS and AFM methods. The results showed that the resistivity of the film improved toward the theoretical values from 2.3 to 1.8 μΩ cm for the 100 nm thickness films. AFM scan of the film showed surface roughness was improved using MSNIS by ion bombarding effect. Depth profiling SIMS result showed Cs level resided in the film was less than 1 × 10 19 at./cm 3. As an application, Cu seed layer deposition on trench structure was investigated. Cross-sectional SEM was employed to see the step coverage of the film. The biasing effect was investigated. The different biasing conditions resulted as the clearly different coverage mode.

  4. Low Temperature Reactive Sputtering of Thin Aluminum Nitride Films on Metallic Nanocomposites.

    Directory of Open Access Journals (Sweden)

    Khaled Sayed Elbadawi Ramadan

    Full Text Available Piezoelectric aluminum nitride thin films were deposited on aluminum-molybdenum (AlMo metallic nanocomposites using reactive DC sputtering at room temperature. The effect of sputtering parameters on film properties was assessed. A comparative study between AlN grown on AlMo and pure aluminum showed an equivalent (002 crystallographic texture. The piezoelectric coefficients were measured to be 0.5±0.1 C m(-2 and 0.9±0.1 C m(-2, for AlN deposited on Al/0.32Mo and pure Al, respectively. Films grown onto Al/0.32Mo however featured improved surface roughness. Roughness values were measured to be 1.3nm and 5.4 nm for AlN films grown on AlMo and on Al, respectively. In turn, the dielectric constant was measured to be 8.9±0.7 for AlN deposited on Al/0.32Mo seed layer, and 8.7±0.7 for AlN deposited on aluminum; thus, equivalent within experimental error. Compatibility of this room temperature process with the lift-off patterning of the deposited AlN is also reported.

  5. Low Temperature Reactive Sputtering of Thin Aluminum Nitride Films on Metallic Nanocomposites.

    Science.gov (United States)

    Ramadan, Khaled Sayed Elbadawi; Evoy, Stephane

    2015-01-01

    Piezoelectric aluminum nitride thin films were deposited on aluminum-molybdenum (AlMo) metallic nanocomposites using reactive DC sputtering at room temperature. The effect of sputtering parameters on film properties was assessed. A comparative study between AlN grown on AlMo and pure aluminum showed an equivalent (002) crystallographic texture. The piezoelectric coefficients were measured to be 0.5±0.1 C m(-2) and 0.9±0.1 C m(-2), for AlN deposited on Al/0.32Mo and pure Al, respectively. Films grown onto Al/0.32Mo however featured improved surface roughness. Roughness values were measured to be 1.3nm and 5.4 nm for AlN films grown on AlMo and on Al, respectively. In turn, the dielectric constant was measured to be 8.9±0.7 for AlN deposited on Al/0.32Mo seed layer, and 8.7±0.7 for AlN deposited on aluminum; thus, equivalent within experimental error. Compatibility of this room temperature process with the lift-off patterning of the deposited AlN is also reported.

  6. Manipulating single second mode transparency in a corrugated waveguide via the thickness of sputtered gold

    International Nuclear Information System (INIS)

    Xu, Dan; Fan, Ya-Xian; Sang, Tang-Qing; Xu, Lan-Lan; Bibi, Aysha; Tao, Zhi-Yong

    2016-01-01

    We propose a classical analog of electromagnetically induced transparency in a cylindrical waveguide with undulated metallic walls. The transparency, induced by multi-mode interactions in waveguides, not only has a narrow line-width, but also consists of a single second-order transverse mode, which corresponds to the Bessel function distributions investigated extensively due to their unique characteristics. By increasing the thickness of sputtered gold layers of the waveguide, we demonstrate a frequency-agile single mode transparency phenomenon in a terahertz radiation. It is found that the center frequency of the transparency is linearly related to the gold thickness, indicating the achievement of a controllable single mode terahertz device. The field distributions at the cross-sections of outlets verify the single second mode transparency and indicate the mechanism of its frequency manipulation, which will significantly benefit the mode-control engineering in terahertz applications. - Highlights: • An analog of electromagnetically induced transparency in terahertz tubes is proposed. • A single second transverse mode of Bessel distributions is observed in the pass band. • The operating frequency can be linearly controlled by the sputtered gold thickness. • We can effectively manipulate the slow down factor of light by the gold thickness. • The transparency characteristics rely on the transition of multi-mode interactions.

  7. Manipulating single second mode transparency in a corrugated waveguide via the thickness of sputtered gold

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Dan [Key Lab of In-fiber Integrated Optics, Ministry of Education of China, Harbin Engineering University, Harbin 150001 (China); Photonics Research Center, College of Science, Harbin Engineering University, Harbin 150001 (China); Fan, Ya-Xian, E-mail: yxfan@hrbeu.edu.cn [Key Lab of In-fiber Integrated Optics, Ministry of Education of China, Harbin Engineering University, Harbin 150001 (China); Photonics Research Center, College of Science, Harbin Engineering University, Harbin 150001 (China); Sang, Tang-Qing; Xu, Lan-Lan; Bibi, Aysha [Key Lab of In-fiber Integrated Optics, Ministry of Education of China, Harbin Engineering University, Harbin 150001 (China); Photonics Research Center, College of Science, Harbin Engineering University, Harbin 150001 (China); Tao, Zhi-Yong, E-mail: zytao@hrbeu.edu.cn [Key Lab of In-fiber Integrated Optics, Ministry of Education of China, Harbin Engineering University, Harbin 150001 (China); Photonics Research Center, College of Science, Harbin Engineering University, Harbin 150001 (China)

    2016-03-11

    We propose a classical analog of electromagnetically induced transparency in a cylindrical waveguide with undulated metallic walls. The transparency, induced by multi-mode interactions in waveguides, not only has a narrow line-width, but also consists of a single second-order transverse mode, which corresponds to the Bessel function distributions investigated extensively due to their unique characteristics. By increasing the thickness of sputtered gold layers of the waveguide, we demonstrate a frequency-agile single mode transparency phenomenon in a terahertz radiation. It is found that the center frequency of the transparency is linearly related to the gold thickness, indicating the achievement of a controllable single mode terahertz device. The field distributions at the cross-sections of outlets verify the single second mode transparency and indicate the mechanism of its frequency manipulation, which will significantly benefit the mode-control engineering in terahertz applications. - Highlights: • An analog of electromagnetically induced transparency in terahertz tubes is proposed. • A single second transverse mode of Bessel distributions is observed in the pass band. • The operating frequency can be linearly controlled by the sputtered gold thickness. • We can effectively manipulate the slow down factor of light by the gold thickness. • The transparency characteristics rely on the transition of multi-mode interactions.

  8. High-power DPL thin films prepared by ion beam sputtering

    Science.gov (United States)

    Liu, Hongxiang; Xiong, Shengming; Zhang, Yundong

    2006-08-01

    Ion beam sputtering enables high laser damage threshold mirrors to be manufactured. Oxygen partial pressure was found to have significant influence on the microstructure and optical properties of HfO II thin films deposited by ion beam sputtering (IBS). Atomic force microscopy studies have shown that the surface of single HfO II films is clearly characterized by deep holes. When oxygen is excessive, the RMS roughness of the surface increases with the presence of the holes, and the transmittance of the single HfO II layers reduces evidently in the shortwave spectral region. The laser-induced damage threshold (LIDT) of HfO II/SiO II multilayer stacks was investigated with a diode pump laser at 1064 nm under a certain repetition frequency. The laser-induced damage morphology of DPL thin films were observed by the optical microscope. SiO II overcoats increase the damage threshold and modify the damage morphology of IBS coatings. The LIDT of the cavity mirrors is > 1 GW/cm2 at 1064 nm (80 ns, 10 KHz).

  9. Improvement of corrosion resistance of transparent conductive multilayer coating consisting of silver layers and transparent metal oxide layers

    International Nuclear Information System (INIS)

    Koike, Katsuhiko; Yamazaki, Fumiharu; Okamura, Tomoyuki; Fukuda, Shin

    2007-01-01

    An optical filter for plasma display panel (PDP) requires an electromagnetic shield with very high ability. The authors investigated a transparent conductive multilayer coating consisting of silver (Ag) layers and transparent metal oxide layers. The durability of the multilayer sputter coating, including the silver layer, is very sensitive to the surrounding atmosphere. For example, after an exposure test they found discolored points on the multilayer sputter coatings, possibly caused by migration of silver atoms in the silver layers. In their investigation, they modified the top surface of the multilayer sputter coatings with transition metals to improve the corrosion resistance of the multilayer coating. Specifically, they deposited transition metals 0.5-2 nm thick on the top surface of the multilayer coatings by sputtering. They chose indium tin oxide (ITO) as the transparent metal oxide. They applied the multilayer sputter coatings of seven layers to a polyethylene terephthalate (PET) film substrate. A cross-sectional structure of the film with the multilayer coatings is PET film/ITO/Ag/ITO/Ag/ITO/Ag/ITO. They evaluated the corrosion resistance of the films by a salt-water immersion test. In the test, they immersed the film with multilayer coatings into salt water, and then evaluated the appearance, transmittance, and electrical resistance of the multilayer coatings. They investigated several transition metals as the modifying material, and found that titanium and tantalum drastically improved the resistance of the multilayer coatings to the salt-water exposure without a significant decline in transmittance. They also investigated the relation between elapsed time after deposition of the modifying materials and resistance to the salt water. Furthermore, they investigated the effects of a heat treatment and an oxide plasma treatment on resistance to the salt water

  10. Significance of negative ion formation in sputtering and SIMS analysis

    International Nuclear Information System (INIS)

    Cuomo, J.J.; Gambino, R.J.; Harper, J.M.E.; Kuptsis, J.D.; Webber, J.C.

    1978-01-01

    An unexpected substrate etching phenomenon during the sputtering of certain intermetallic compounds has been found to be caused by a large flux of negative metal ions from the sputtering target. The substrates directly under the target in a diode geometry are etched (eroded) rather than coated with a film. The occurrence of this substrate etching has been correlated with negative ion yields measured by secondary ion mass spectroscopy (SIMS). We find a high yield of negative metal ions from several intermetallic compounds in addition to the highly ionic compounds previously reported. A model based on electron charge transfer is presented which predicts when negative ion formation will be important, and the dependence of etch rate on target voltage is also treated. We predict that negative ion effects will be found in the sputtering of a wide range of compounds

  11. Magnetron sputtering cathode for low power density operation

    Directory of Open Access Journals (Sweden)

    T. Motomura

    2017-12-01

    Full Text Available A novel magnetron sputtering cathode with a magnetic mirror configuration is proposed, for low power density operation. The magnetic field profiles are simply constructed using two cylindrical permanent magnets positioned behind the disk-shaped sputtering target of 50 mm in diameter. The magnetic mirror configuration near the center and the outer edges of the target enables low power density operation up to 0.25 W/cm2 in the case of DC input power of 5 W. A sputtering rate of ∼0.2 nm/min was obtained under experimental conditions with target-substrate distance of 280 mm, Ar gas pressure of 0.1 Pa, and DC input power of 15 W.

  12. Angular distributions of sputtered particles from NiTi alloy

    International Nuclear Information System (INIS)

    Neshev, I.; Hamishkeev, V.; Chernysh, V.S.; Postnikov, S.; Mamaev, B.

    1993-01-01

    The angular distributions of sputtered Ni and Ti from a polycrystalline NiTi (50-50%) alloy are investigated by Auger electron spectroscopy and Rutherford backscattering spectroscopy. A difference in the angular distributions is observed with Ni being sputtered preferentially near the surface normal. A computer program for the calculation of the angular distributions of constituents sputtered from binary targets is created and used. The mechanisms responsible for the observed differences in the angular distributions are discussed. It is found that the collisional cascade theory is not directly applicable to the results of the constituents' angular distributions obtained in the presence of oxygen. The fitted coefficients of bombardment-induced segregation are found to be greater than the experimentally obtained ones. (author)

  13. Recent advancements in sputter-type heavy negative ion sources

    International Nuclear Information System (INIS)

    Alton, G.D.

    1989-01-01

    Significant advancement have been made in sputter-type negative ion sources which utilize direct surface ionization, or a plasma to form the positive ion beam used to effect sputtering of samples containing the material of interest. Typically, such sources can be used to generate usable beam intensities of a few μA to several mA from all chemically active elements, depending on the particular source and the electron affinity of the element in question. The presentation will include an introduction to the fundamental processes underlying negative ion formation by sputtering from a low work function surface and several sources will be described which reflect the progress made in this technology. 21 refs., 9 figs., 1 tab

  14. Optical properties of aluminum nitride thin films grown by direct-current magnetron sputtering close to epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Stolz, A. [Institut d' Electronique de Microélectronique et de Nanotechnologie (IEMN), UMR CNRS 8520, PRES Lille, Université Nord de France, Avenue Poincaré, 59652 Villeneuve d' Ascq Cedex (France); Soltani, A., E-mail: ali.soltani@iemn.univ-lille1.fr [Institut d' Electronique de Microélectronique et de Nanotechnologie (IEMN), UMR CNRS 8520, PRES Lille, Université Nord de France, Avenue Poincaré, 59652 Villeneuve d' Ascq Cedex (France); Abdallah, B. [Department of Materials Physics, Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic); Charrier, J. [Fonctions Optiques pour les Technologies de l' informatiON (FOTON), UMR CNRS 6082, 6, rue de Kerampont CS 80518, 22305 Lannion Cedex (France); Deresmes, D. [Institut d' Electronique de Microélectronique et de Nanotechnologie (IEMN), UMR CNRS 8520, PRES Lille, Université Nord de France, Avenue Poincaré, 59652 Villeneuve d' Ascq Cedex (France); Jouan, P.-Y.; Djouadi, M.A. [Institut des Matériaux Jean Rouxel – IMN, UMR CNRS 6502, 2, rue de la Houssinère BP 32229, 44322 Nantes (France); Dogheche, E.; De Jaeger, J.-C. [Institut d' Electronique de Microélectronique et de Nanotechnologie (IEMN), UMR CNRS 8520, PRES Lille, Université Nord de France, Avenue Poincaré, 59652 Villeneuve d' Ascq Cedex (France)

    2013-05-01

    Low-temperature Aluminum Nitride (AlN) thin films with a thickness of 3 μm were deposited by Direct-Current magnetron sputtering on sapphire substrate. They present optical properties similar to those of epitaxially grown films. Different characterization methods such as X-Ray Diffraction, Transmission Electron Microscopy and Atomic Force Microscopy were used to determine the structural properties of the films such as its roughness and crystallinity. Newton interferometer was used for stress measurement of the films. Non-destructive prism-coupling technique was used to determine refractive index and thickness homogeneity by a mapping on the whole sample area. Results show that AlN films grown on AlGaN layer have a high crystallinity close to epitaxial films, associated to a low intrinsic stress for low thickness. These results highlight that it is possible to grow thick sample with microstructure and optical properties close to epitaxy, even on a large surface. - Highlights: ► Aluminum Nitride sputtering technique with a low temperature growth process ► Epitaxial quality of two microns sputtered Aluminum Nitride film ► Optics as a non-destructive accurate tool for acoustic wave investigation.

  15. Full Sputtering Deposition of Thin Film Solar Cells: A Way of Achieving High Efficiency Sustainable Tandem Cells?

    Science.gov (United States)

    Vilcot, J.-P.; Ayachi, B.; Aviles, T.; Miska, P.

    2017-11-01

    In the first part of this paper, we will show that a sputtering-based fabrication process exhibiting a low environmental footprint has been developed for the fabrication of copper indium gallium selenide (CIGS) absorbing material. Its originality lies in using room temperature sputtering in a pulsed—direct current mode of a single quaternary target followed by a post-anneal. At any stage of the process, selenium or sulfur atmosphere is used. Inert gas is used, respectively argon and a forming gas, for the deposition and annealing step, respectively. CIGS cells have been fabricated using such an absorbing layer. They exhibit an efficiency close to 12%. A tandem cell approach, using a thin film technology in conjunction with the well-established Si technology, is a promising technique, achieving cells with 30%, and higher, efficiency. Such cells are awaited, jointly with a stronger implementation of low environmental footprint technologies, as a vision for 2030. In the first section, sputtering technique has shown its ability to be developed in such a way achieving an environmentally friendly process that can be moreover compatible to be co-integrated with, for example, Si technology. In a second section, we will present a prospective discussion on the materials that can be applied to produce a sustainable approach for such a tandem cell configuration.

  16. Heteroepitaxial growth of CuInS2 thin films on sapphire by radio frequency reactive sputtering

    International Nuclear Information System (INIS)

    He, Y.B.; Kriegseis, W.; Meyer, B.K.; Polity, A.; Serafin, M.

    2003-01-01

    Direct heteroepitaxial growth of uniform stoichiometric CuInS 2 (CIS) thin films on sapphire (0001) substrates has been achieved by radio frequency reactive sputtering. X-ray ω-2θ scans reveal that the sputtered layers grow in a (112) orientation with a chalcopyrite structure. A rocking curve full width at half maximum of about 0.05 deg. (180 arc sec) for the (112) peak demonstrates a nearly perfect out-of-plane arrangement of CIS (112) parallel sapphire (0001). X-ray diffraction Phi scans further illustrate an excellent in-plane ordering of CIS [1-bar10] parallel sapphire (101-bar0). The sputtered thin CIS epilayers had a smooth surface with a typical root-mean-square roughness of about 3.3 nm as evaluated by atomic force microscopy. The epitaxial growth of tetragonal CIS on hexagonal sapphire provides evidence that heteroepitaxial growth may be realized between structures of different symmetry, such as films of cubic or tetragonal structures on hexagonal substrates or vice versa

  17. Lattice distortion due to surface treatment of bias sputtering revealed by extremely asymmetric X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Y.; Akimoto, K.; Emoto, T.; Kikuchi, S.; Itagaki, K.; Namita, H

    2004-07-15

    Strain fields near InGaP or GaAs surfaces due to bias sputtering (Ar plasma-ion irradiation) for surface cleaning were measured by using a strain-sensitive X-ray diffraction technique. An extremely asymmetric InGaP or GaAs 1 1 3 reflection of the sample was measured to observe strain fields. We found that strain fields near InGaP or GaAs surfaces due to bias sputtering are affected by the bias voltage (Ar plasma-ion irradiation energy) used in this surface-cleaning treatment. By comparing measured 1 1 3 rocking curves and calculated ones based on the dynamical theory of X-rays, we estimated the thickness of a strained layer and a maximum strain at the surface. Resulting estimated parameters clearly show the bias sputtering to have two effects. One should be corresponding to the surface cleaning process of removing oxides on surfaces. The other is the lattice expansion, which is thought to be caused by compositional fluctuation near the surface or peening process of Ar ion.

  18. Nanoporous sputtered platinum-iridium-thinfilms for medical and energy applications; Nanoporoese gesputterte Platin-Iridium-Schichten fuer Anwendungen in der Medizin- und Energietechnik

    Energy Technology Data Exchange (ETDEWEB)

    Ganske, Gerald

    2012-10-05

    Sputtering makes it possible to create thinfilms of only a few atom layers and to customize them for special applications by adjusting the deposition parameters. In this work interface-layers are deposited and characterized in biological systems as stimulation electrodes for neural cells and as catalysts in hydrogen fuel cells. First of all, highly porous platinum films were created by sputtering at a pressure of 9 Pa and low power of less than 100 W. These parameters are an ideal compromise between deposition rate, porosity and disordered crystal structure of the layers. Investigations on co-sputtered platinum-iridium-films (PtIr) showed that these films form homogeneous structures and no distinction between the separate layers is possible. It was demonstrated that these films obtain the crystal structure of Pt as well as the finer cauliflower-like structure of iridium, if the atoms reach the substrate surface only with their thermal energy. Furthermore, it was shown that the film composition reflects the sputtering power of the separate targets in a linear way. The structure of the films can be predicted by means of monte-carlo-simulation, which was verified by SEM-pictures. The ratio of the sputtering power can be used to control the amount of interface elements which was confirmed by electrochemical tests. Electrode materials for the stimulation of neural cells need a large electrochemically active surface that allows for an interface between electron and ion conductivity. Test on platinum, iridium and PtIr have shown that the films sputtered at the lowest impact energy do have the largest active surface as well as the largest charge delivery capacity (CDC). Iridium films show the highest CDC (48 mC/cm{sup 2}), followed by platinum-iridium (2 mC/cm{sup 2}, 100 W power at both targets) and pure platinum (16 mC/cm{sup 2}). This can be explained by the large surface area of iridium and its electrochemical activation process. Although PtIr layers also show an

  19. Homogeneous bilateral block shifts

    Indian Academy of Sciences (India)

    A new 3-parameter family of homogeneous 2-by-2 block shifts is described. These are the first examples of irreducible homogeneous bilateral block shifts of block size larger than 1. Author Affiliations. Adam Korányi1. Department of Mathematics, The Graduate Center, City University of New York, New York, NY 10016, USA ...

  20. Arc generation from sputtering plasma-dielectric inclusion interactions

    International Nuclear Information System (INIS)

    Wickersham, C.E. Jr.; Poole, J.E.; Fan, J.S.

    2002-01-01

    Arcing during sputter deposition and etching is a significant cause of particle defect generation during device fabrication. In this article we report on the effect of aluminum oxide inclusion size, shape, and orientation on the propensity for arcing during sputtering of aluminum targets. The size, shape, and orientation of a dielectric inclusion plays a major role in determining the propensity for arcing and macroparticle emission. In previous studies we found that there is a critical inclusion size required for arcing to occur. In this article we used high-speed videos, electric arc detection, and measurements of particle defect density on wafers to study the effect of Al 2 O 3 inclusion size, shape, and orientation on arc rate, intensity, and silicon wafer particle defect density. We found that the cross-sectional area of the inclusion exposed to the sputtering plasma is the critical parameter that determines the arc rate and rate of macroparticle emission. Analysis of the arc rate, particle defect density, and the intensity of the optical emission from the arcing plasma indicates that the critical aluminum oxide inclusion area for arcing is 0.22±0.1 mm2 when the sputtering plasma sheath dark-space λ d , is 0.51 mm. Inclusions with areas greater than this critical value readily induce arcing and macroparticle ejection during sputtering. Inclusions below this critical size do not cause arcing or macroparticle ejection. When the inclusion major axis is longer than 2λ d and lies perpendicular to the sputter erosion track tangent, the arcing activity increases significantly over the case where the inclusion major axis lies parallel to the erosion track tangent

  1. Advances in sputtered and ion plated solid film lubrication

    Science.gov (United States)

    Spalvins, T.

    1985-01-01

    The glow discharge or ion assisted vacuum deposition techniques, primarily sputtering and ion plating, have rapidly emerged and offer great potential to deposit solid lubricants. The increased energizing of these deposition processes lead to improved adherence and coherence, favorable morphological growth, higher density, and reduced residual stresses in the film. These techniques are of invaluable importance where high precision machines tribo-components require very thin, uniform lubricating films (0.2 m), which do not interface with component tolerances. The performance of sputtered MoS2 films and ion plated Au and Pb films are described in terms of film thickness, coefficient of friction, and wear lives.

  2. Plasma diagnostics during magnetron sputtering of aluminum doped zinc oxide

    DEFF Research Database (Denmark)

    Stamate, Eugen; Crovetto, Andrea; Sanna, Simone

    2016-01-01

    Plasma parameters during magnetron sputtering of aluminum-doped zinc oxide are investigated with optical emission spectroscopy, electrostatic probes and mass spectrometry with the aim of understanding the role of negative ions of oxygen during the film growth and improving the uniformity of the f......Plasma parameters during magnetron sputtering of aluminum-doped zinc oxide are investigated with optical emission spectroscopy, electrostatic probes and mass spectrometry with the aim of understanding the role of negative ions of oxygen during the film growth and improving the uniformity...

  3. Nanoporous zinc oxide films prepared by magnetron sputtering

    International Nuclear Information System (INIS)

    Ghimpu, L.; Lupan, O.; Popescu, L.; Tiginyanu, I.M.

    2011-01-01

    In this paper we demonstrate an inexpensive approach for the fabrication of nanoporous zinc oxide films by using magnetron sputtering. Study of the structural properties proves the crystallographic perfection of porous nanostructures and the possibility of its controlling by adjusting the technological parameters in the growth process. The XRD pattern of nanoporous ZnO films exhibits high intensity of the peaks relative to the background signal which is indicative of the ZnO hexagonal phase and a good crystallinity of the samples grown by magnetron sputtering.

  4. Growth of Sr1-xNdxCuOy thin films by rf-magnetron sputtering and pulsed-laser deposition

    International Nuclear Information System (INIS)

    Sugii, N.; Ichikawa, M.; Kuba, K.; Sakurai, T.; Iamamoto, K.; Yamauchi, H.

    1992-01-01

    This paper reports on Sr 1- x Nd x CuO y thin films grown on SrTiO 3 substrates by rf-magnetron sputtering and pulsed-laser deposition. The sputter-deposited film with x=0 has an infinite-layer structure whose lattice constants are: a=0.390 nm and c=0.347 nm. When x is larger than 0.1, the films contain a phase of the Sr 14 Cu 24 O 41 structure. The laser-deposited films of Sr 1- x Nd x CuO y with x ≥ 0.075 were single phase of the infinite-layer structure. The lattice parameter c decreased and the lattice parameter a increased, as the Nd content, x, increased. The films with x=0.10 and 0.125 exhibited superconducting onset temperatures around 26 K. Weak Meissner signals were observed for these films at temperatures below 30 K

  5. Growth and morphology of sputtered aluminum thin films on P3HT surfaces.

    Science.gov (United States)

    Kaune, Gunar; Metwalli, Ezzeldin; Meier, Robert; Körstgens, Volker; Schlage, Kai; Couet, Sebastien; Röhlsberger, Ralf; Roth, Stephan V; Müller-Buschbaum, Peter

    2011-04-01

    Growth and morphology of an aluminum (Al) contact on a poly(3-hexylthiophene) (P3HT) thin film are investigated with X-ray methods and related to the interactions at the Al:P3HT interface. Grazing incidence small-angle scattering (GISAXS) is applied in situ during Al sputter deposition to monitor the growth of the layer. A growth mode is found, in which the polymer surface is wetted and rapidly covered with a continuous layer. This growth type results in a homogeneous film without voids and is explained by the strong chemical interaction between Al and P3HT, which suppresses the formation of three-dimensional cluster structures. A corresponding three stage growth model (surface bonding, agglomeration, and layer growth) is derived. X-ray reflectivity shows the penetration of Al atoms into the P3HT film during deposition and the presence of a 2 nm thick intermixing layer at the Al:P3HT interface. © 2011 American Chemical Society

  6. Multiresonant layered plasmonic films

    Energy Technology Data Exchange (ETDEWEB)

    DeVetter, Brent M. [Pacific Northwest National Laboratory, Richland, Washington, United States; Bernacki, Bruce E. [Pacific Northwest National Laboratory, Richland, Washington, United States; Bennett, Wendy D. [Pacific Northwest National Laboratory, Richland, Washington, United States; Schemer-Kohrn, Alan [Pacific Northwest National Laboratory, Richland, Washington, United States; Alvine, Kyle J. [Pacific Northwest National Laboratory, Richland, Washington, United States

    2017-01-01

    Multi-resonant nanoplasmonic films have numerous applications in areas such as nonlinear optics, sensing, and tamper indication. While techniques such as focused ion beam milling and electron beam lithography can produce high-quality multi-resonant films, these techniques are expensive, serial processes that are difficult to scale at the manufacturing level. Here, we present the fabrication of multi-resonant nanoplasmonic films using a layered stacking technique. Periodically-spaced gold nanocup substrates were fabricated using self-assembled polystyrene nanospheres followed by oxygen plasma etching and metal deposition via magnetron sputter coating. By adjusting etch parameters and initial nanosphere size, it was possible to achieve an optical response ranging from the visible to the near-infrared. Singly resonant, flexible films were first made by performing peel-off using an adhesive-coated polyolefin film. Through stacking layers of the nanofilm, we demonstrate fabrication of multi-resonant films at a fraction of the cost and effort as compared to top-down lithographic techniques.

  7. Fabrication of Nb2O5/SiO2 mixed oxides by reactive magnetron co-sputtering

    International Nuclear Information System (INIS)

    Juškevičius, Kęstutis; Audronis, Martynas; Subačius, Andrius; Kičas, Simonas; Tolenis, Tomas; Buzelis, Rytis; Drazdys, Ramutis; Gaspariūnas, Mindaugas; Kovalevskij, Vitalij; Matthews, Allan; Leyland, Adrian

    2015-01-01

    This paper investigates niobia/silica mixed oxide thin films deposited by reactive pulse-DC/RF magnetron co-sputtering of Nb and Si metal targets at room temperature. The reactive gas flow during the sputtering processes was either controlled by direct mass flow rate (i.e. constant reactive gas flow) or by an active feedback process control system. 61% and 137% higher deposition rates of Nb 2 O 5 and SiO 2 layers, respectively, were obtained using the latter technique as compared to constant reactive gas flow. Films exhibited bulk or near-bulk density. All mixture films produced in this study had an amorphous structure. A volume law of mixtures was used to determine the coating composition. It is shown that the fraction of SiO 2 or/and Nb 2 O 5 has a linear dependency on sputter target power density. On this basis, rugate filter coating designs can be easily deposited, where refractive index gradually varies between that of pure Nb 2 O 5 and pure SiO 2 . Substantially less inhomogeneity of coating mixtures was found in films produced using a reactive sputtering process with feedback-control. - Highlights: • 61% and 137% increase in deposition rates of Nb 2 O 5 and SiO 2 • Rugate coating designs can be readily deposited. • Nb 2 O 5 /SiO 2 mixture films exhibited bulk or near-bulk density. • Optimized process leads to stoichiometric and homogenous mixtures. • Films are amorphous and suitable for low loss optical coatings

  8. Optical properties of d.c. magneto sputtered tantalum and titanium ...

    Indian Academy of Sciences (India)

    Administrator

    Department of Physics, University of Rajasthan, Jaipur 302 004, India. MS received 19 April 2009; revised 20 May 2009. Abstract. ... Magnetron sputtering has become the process of choice for the deposition of wide range of important ... Sputtering unit with multiple targets. (a) View of sputtering unit with Argon cylinder and.

  9. In situ Polarized Neutron Reflectometry: Epitaxial Thin-Film Growth of Fe on Cu(001) by dc Magnetron Sputtering

    Science.gov (United States)

    Kreuzpaintner, Wolfgang; Wiedemann, Birgit; Stahn, Jochen; Moulin, Jean-François; Mayr, Sina; Mairoser, Thomas; Schmehl, Andreas; Herrnberger, Alexander; Korelis, Panagiotis; Haese, Martin; Ye, Jingfan; Pomm, Matthias; Böni, Peter; Mannhart, Jochen

    2017-05-01

    The stepwise growth of epitaxial Fe on Cu (001 )/Si (001 ) , investigated by in situ polarized neutron reflectometry is presented. A sputter deposition system was integrated into the neutron reflectometer AMOR at the Swiss neutron spallation source SINQ, which enables the analysis of the microstructure and magnetic moments during all deposition steps of the Fe layer. We report on the progressive evolution of the accessible parameters describing the microstructure and the magnetic properties of the Fe film, which reproduce known features and extend our knowledge on the behavior of ultrathin iron films.

  10. Titanium-doped sputter-deposited AlN infrared whispering gallery mode microlaser on optical fibers.

    Science.gov (United States)

    Maqbool, Muhammad; Main, Kyle; Kordesch, Martin

    2010-11-01

    Optical fibers of 12 μm diameter were coated with a sputter-deposited layer (4 μm thick) of titanium (1 at. %)-doped amorphous aluminum nitride. When optically pumped by an Nd:YAG green laser at 532 nm, laser action was observed in whispering gallery modes around the fiber (in a ring shape) at 780.5 nm with a quality factor Q > 1500. Other modes were also observed between 775 and 800 nm. The primary and secondary modes give a mode separation of 4.6 nm. No waveguide modes were observed in the cavity.

  11. RF magnetron sputtering deposition of NiO/Ni bilayer and approach of the Magnetic behavior using the Preisach model

    Energy Technology Data Exchange (ETDEWEB)

    Bendjerad, A., E-mail: bendjerad@gmail.com [L.E.B. Research Laboratory, Electrical Engineering Department, University of Batna 2, Batna (Algeria); Head of Clean Room, L.E.A Laboratory, University of Batna 2, Batna (Algeria); Boukhtache, S. [L.E.B. Research Laboratory, Electrical Engineering Department, University of Batna 2, Batna (Algeria); Benhaya, A. [Head of Clean Room, L.E.A Laboratory, University of Batna 2, Batna (Algeria); Lahmar, A. [Laboratoire de Physiques de la Matière Condensée (LPMC), University of Picardie Jules Vernes, Amiens (France); Zergoug, M. [C.S.C Centre de soudage et de contrôle, Dely Ibrahim, BP 64 Chéraga, Alger (Algeria); Luneau, D. [Université Claude Bernard Lyon 1 Laboratoire des Multimatériaux, (UMR 5615) 69622 cedex (France)

    2017-04-15

    Bilayer of nickel and nickel oxide were deposited on glass substrates using RF magnetron sputtering technique. The magnetic properties of the prepared thin films were carried out at room temperature in both parallel and perpendicular magnetic field to the sample. The Preisach model was applied to provide a mathematical model of the magnetic hysteresis loop in the case of parallel geometry, along the easy axis of the bi-layer NiO / Ni. Good agreement was obtained between the theoretical and experimental results.

  12. Charge ordering in reactive sputtered (1 0 0) and (1 1 1) oriented epitaxial Fe3O4 films

    KAUST Repository

    Mi, Wenbo

    2013-06-01

    Epitaxial Fe3O4 films with (1 0 0) and (1 1 1) orientations fabricated by reactive sputtering present simultaneous magnetic and electrical transitions at 120 and 124 K, respectively. The symmetry decreases from face-centered cubic to monoclinic structure across the Verwey transition. Extra spots with different brightness at different positions appear in selected-area diffraction patterns at 95 K. The extra spots come from the charge ordering of outer-layer electrons of Fe atoms, and should be related to the charge ordering of octahedral B-site Fe atoms. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  13. One-step aluminium-assisted crystallization of Ge epitaxy on Si by magnetron sputtering

    International Nuclear Information System (INIS)

    Liu, Ziheng; Hao, Xiaojing; Ho-Baillie, Anita; Green, Martin A.

    2014-01-01

    In this work, one-step aluminium-assisted crystallization of Ge on Si is achieved via magnetron sputtering by applying an in-situ low temperature (50 °C to 150 °C) heat treatment in between Al and Ge depositions. The effect of heat treatment on film properties and the growth mechanism of Ge epitaxy on Si are studied via X-ray diffraction, Raman and transmission electron microscopy analyses. Compared with the conventional two-step process, the one-step aluminium-assisted crystallization requires much lower thermal budget and results in pure Ge epitaxial layer, which may be suitable for use as a virtual substrate for the fabrication of III-V solar cells

  14. Highly transparent conductive ITO/Ag/ITO trilayer films deposited by RF sputtering at room temperature

    Directory of Open Access Journals (Sweden)

    Ningyu Ren

    2017-05-01

    Full Text Available ITO/Ag/ITO (IAI trilayer films were deposited on glass substrate by radio frequency magnetron sputtering at room temperature. A high optical transmittance over 94.25% at the wavelength of 550 nm and an average transmittance over the visual region of 88.04% were achieved. The calculated value of figure of merit (FOM reaches 80.9 10-3 Ω-1 for IAI films with 15-nm-thick Ag interlayer. From the morphology and structural characterization, IAI films could show an excellent correlated electric and optical performance if Ag grains interconnect with each other on the bottom ITO layer. These results indicate that IAI trilayer films, which also exhibit low surface roughness, will be well used in optoelectronic devices.

  15. Elastic and inelastic surface effects on ion penetration and the resulting sputtering and backscattering

    International Nuclear Information System (INIS)

    Hassanein, A.M.; Smith, D.L.

    1985-01-01

    The computer code ITMC (Ion Transport in Materials and Compounds) has been developed to study in detail the transport of charged particles in solid materials and surface related phenomena such as sputtered atoms and backscattered ions. The code is based on Monte Carlo methods to follow the path and the damage produced by the charged particles in three dimension as they slow down in target materials. Single-element targets as well as alloys with possible different surface and bulk compositions or with layered structures of different materials can be used. Various models developed to calculate the inelastic energy losses with target electrons can be used in the code. Most known interatomic potentials can also be used to calculate the elastic energy losses. The major advantages of the code are its ability and flexibility to use and compare various models of elastic and inelastic energy losses in any target with different compounds and different surface and bulk composition

  16. ZnO thin film synthesis by reactive radio frequency magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Şenay, Volkan, E-mail: vsenay@bayburt.edu.tr [Bayburt University, Primary Science Education Department, Bayburt, 69000 (Turkey); Pat, Suat; Korkmaz, Şadan; Aydoğmuş, Tuna; Elmas, Saliha; Özen, Soner; Ekem, Naci [Eskisehir Osmangazi University, Physics Department, Eskisehir, 26480 (Turkey); Balbağ, M. Zafer [Eskisehir Osmangazi University, Education Faculty, Eskisehir, 26480 (Turkey)

    2014-11-01

    Highlights: • Band gaps of the layer are affected by the film thickness. • Nano structured ZnO deposited. • Spectral dependence of reflectance of deposited ZnO thin films. - Abstract: In this study, ZnO thin films were deposited on glass substrates by reactive RF magnetron sputtering method at argon–oxygen gas mixing (1:1) atmosphere. Some properties of the synthesized films were investigated by interferometry, UV–vis spectrophotometer, atomic force microscopy, and tensiometer. Tauc method was adopted to estimate the optical band gaps. The band gaps of the deposited films were affected by film thickness. We concluded that the surface composition plays a substantial role in the values of the band gaps. Nanocrystalline structures were detected in all produced samples.

  17. ZnO thin film synthesis by reactive radio frequency magnetron sputtering

    International Nuclear Information System (INIS)

    Şenay, Volkan; Pat, Suat; Korkmaz, Şadan; Aydoğmuş, Tuna; Elmas, Saliha; Özen, Soner; Ekem, Naci; Balbağ, M. Zafer

    2014-01-01

    Highlights: • Band gaps of the layer are affected by the film thickness. • Nano structured ZnO deposited. • Spectral dependence of reflectance of deposited ZnO thin films. - Abstract: In this study, ZnO thin films were deposited on glass substrates by reactive RF magnetron sputtering method at argon–oxygen gas mixing (1:1) atmosphere. Some properties of the synthesized films were investigated by interferometry, UV–vis spectrophotometer, atomic force microscopy, and tensiometer. Tauc method was adopted to estimate the optical band gaps. The band gaps of the deposited films were affected by film thickness. We concluded that the surface composition plays a substantial role in the values of the band gaps. Nanocrystalline structures were detected in all produced samples

  18. Performance of plasma sputtered fuel cell electrodes with ultra-low Pt loadings

    Energy Technology Data Exchange (ETDEWEB)

    Cavarroc, M.; Ennadjaoui, A. [MID Dreux Innovation, CAdD, 4 Rue Albert Caquot-28500 Vernouillet (France); Mougenot, M.; Brault, P.; Escalier, R.; Tessier, Y. [Groupe de Recherches sur l' Energetique des Milieux Ionises, CNRS Universite d' Orleans, BP6744, 14 rue d' Issoudun, 45067 Orleans (France); Durand, J.; Roualdes, S. [Institut Europeen des Membranes, ENSCM, UM2, CNRS, Universite Montpellier 2, CC047, Place Eugene Bataillon, 34095 Montpellier cedex 5 (France); Sauvage, T. [Conditions Extremes et Materiaux, Haute Temperature et Irradiation, UPR3079 CNRS, Site Cyclotron, 3A rue de la Ferollerie, 45071 Orleans Cedex 2 (France); Coutanceau, C. [Laboratoire de Catalyse en Chimie Organique, UMR6503 Universite de Poitiers, CNRS, 86022, Poitiers (France)

    2009-04-15

    Ultra-low Pt content PEMFC electrodes have been manufactured using magnetron co-sputtering of carbon and platinum on a commercial E-Tek {sup registered} uncatalyzed gas diffusion layer in plasma fuel cell deposition devices. Pt loadings of 0.16 and 0.01 mg cm{sup -2} have been realized. The Pt catalyst is dispersed as small clusters with size less than 2 nm over a depth of 500 nm. PEMFC test with symmetric electrodes loaded with 10 {mu}g cm{sup -2} led to maximum reproducible power densities as high as 0.4 and 0.17 W cm{sup -2} with Nafion {sup registered} 212 and Nafion {sup registered} 115 membranes, respectively. (author)

  19. Sputtering-induced surface topography on F.C.C. metals

    International Nuclear Information System (INIS)

    Carter, G.; Katardjiev, I.V.; Nobes, M.J.; Whitton, J.L.

    1987-01-01

    High fluence ion implantation of solids is known both to lead to new phase evolution and to modify, by sputtering, the surface topography of the solid. In the past the two processes have been separated by the use of only intermediate, but variable species, fluences in the former (e.g. by mixing of two-layer systems) or high fluence, inert gas or self-ion irradiation in the latter type of study. In the present study a variety of very high fluence (greater than 10 19 ions cm -2 ) implants into polycrystalline and single-crystal copper substrates have been studied to elucidate both mixing (and possible phase formation) and topographic evolution effects. The species were chosen to exert similar ballistic or collisional processes but different chemical or metallurgical effects in the substrate. (orig.)

  20. RF-sputter-deposited magnesium oxide films as high-quality adjustable tunnel barriers

    International Nuclear Information System (INIS)

    Villegier, J.C.; Radparvar, M.; Yu, L.S.; Faris, S.M.

    1989-01-01

    High quality RF-sputtered MgO films are used as tunnel barriers to fabricate small area, niobium nitride Josephson tunnel junctions. A magnesium oxide barrier deposited as a single layer, or as a multilayer film, results in devices with similar characteristics. Annealing trilayers at temperatures in excess of 250 0 C for several hours decrease junction current density and improve device quality presumably by increasing barrier heights through reducing resonant tunneling states. A self-aligned process utilizing only two mask levels is used to produce junctions as small as 0.5 μm/sup 2/ with excellent critical current uniformity. These junctions exhibit energy gaps of 5.1 mV and low subgap currents at current densities in excess of 1000 A/cm/sup 2/ which make them suitable for a variety of applications such as SIS mixers and logic circuits

  1. Tayloring of peek bio activity: impact of plasma and gold sputtered interface

    International Nuclear Information System (INIS)

    Reznickova, A.; Siegel, J.; Svorcik, V.

    2015-01-01

    Full text: This paper presents a novel way of Polyetheretherketone (PEEK) modification resulting in asymmetric samples with two different types of the surface: plasma activated and gold sputtered and its impact on adhesion of mouse fibroblasts (L929). The surface properties of pristine PEEK and its modified counterparts were studied by several techniques, such as XPS, goniometry, AFM and SEM. Biological response of L929 cells seeded on pristine and plasma treated PEEK matrices was evaluated in terms of cell adhesion, spreading, morphology, proliferation, and metabolic activity. Plasma treatment increased the surface wettability of PEEK and led to changes in its surface morphology and chemistry. The XPS method showed a decrease in carbon concentration and increase of gold concentration with increasing plasma treatment. Cell adhesion measured on prepared samples was directly proportional to the thickness of the gold layer on the sample. (Authors)

  2. Design of experiment evaluation of sputtered thin film platinum surface metallization on alumina substrate for implantable conductive structures.

    Science.gov (United States)

    Kiele, P; Cvancara, P; Mueller, M; Stieglitz, T

    2017-07-01

    Reliability and reproducibility of implants and their fabrication are highly depending on the assembly and packaging procedures. Individual fabrication skills like soldering introduce inaccuracies and should be avoided as much as possible. Screen printing is often utilized for the metallization of ceramics. Using platinum/gold (Pt/Au) paste liquidus diffusion leads to a low adhesion strength of the Pt/Au pads after soldering. As an alternative, sputtering of thin film surface metallization was investigated. However, this alternative comes with a huge amount of different layer and parameter setups. In order to keep the amount of experiments and data acquisition in a reasonable magnitude, the Design of Experiment (DoE) evaluation displays a powerful tool. We found an optimal layer setup that maximizes the adhesion strength of the layer, while simultaneously minimizing the sheet resistance and removing the dependency of soldering time.

  3. High-reflectance magnetron-sputtered scandium-based x-ray multilayer mirrors for the water window.

    Science.gov (United States)

    Burcklen, C; de Rossi, S; Meltchakov, E; Dennetière, D; Capitanio, B; Polack, F; Delmotte, F

    2017-05-15

    We present an experimental comparison of several Sc-based short period multilayer mirrors including Cr/Sc with B4C barrier layers and CrNx/Sc, and we propose a new material combination that provides high reflectance in the water window domain. Multilayer samples with period thickness in the range 1.5-1.7 nm have been deposited by magnetron sputtering and characterized by x-ray reflectometry with a Cu-Kα source and with synchrotron radiation near the Sc-L2,3 edge. Best results are achieved by combining the nitridation of Cr layers and the addition of B4C barrier layers. Near normal incidence reflectance as high as 23% has been measured at photon energy of 397 eV. A simulation model of the multilayer structure is proposed and it predicts that reflectance higher than 32% is achievable with CrNx/B4C/Sc mirrors.

  4. Blocked Randomization with Randomly Selected Block Sizes

    Directory of Open Access Journals (Sweden)

    Jimmy Efird

    2010-12-01

    Full Text Available When planning a randomized clinical trial, careful consideration must be given to how participants are selected for various arms of a study. Selection and accidental bias may occur when participants are not assigned to study groups with equal probability. A simple random allocation scheme is a process by which each participant has equal likelihood of being assigned to treatment versus referent groups. However, by chance an unequal number of individuals may be assigned to each arm of the study and thus decrease the power to detect statistically significant differences between groups. Block randomization is a commonly used technique in clinical trial design to reduce bias and achieve balance in the allocation of participants to treatment arms, especially when the sample size is small. This method increases the probability that each arm will contain an equal number of individuals by sequencing participant assignments by block. Yet still, the allocation process may be predictable, for example, when the investigator is not blind and the block size is fixed. This paper provides an overview of blocked randomization and illustrates how to avoid selection bias by using random block sizes.

  5. Blocked randomization with randomly selected block sizes.

    Science.gov (United States)

    Efird, Jimmy

    2011-01-01

    When planning a randomized clinical trial, careful consideration must be given to how participants are selected for various arms of a study. Selection and accidental bias may occur when participants are not assigned to study groups with equal probability. A simple random allocation scheme is a process by which each participant has equal likelihood of being assigned to treatment versus referent groups. However, by chance an unequal number of individuals may be assigned to each arm of the study and thus decrease the power to detect statistically significant differences between groups. Block randomization is a commonly used technique in clinical trial design to reduce bias and achieve balance in the allocation of participants to treatment arms, especially when the sample size is small. This method increases the probability that each arm will contain an equal number of individuals by sequencing participant assignments by block. Yet still, the allocation process may be predictable, for example, when the investigator is not blind and the block size is fixed. This paper provides an overview of blocked randomization and illustrates how to avoid selection bias by using random block sizes.

  6. 31 CFR 595.301 - Blocked account; blocked property.

    Science.gov (United States)

    2010-07-01

    ... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY TERRORISM SANCTIONS REGULATIONS General Definitions § 595.301 Blocked account; blocked property. The terms blocked account and blocked...

  7. Structure and morphology of magnetron sputter deposited ultrathin ZnO films on confined polymeric template

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Ajaib [Discipline of Metallurgy Engineering and Materials Science, Indian Institute of Technology Indore, Indore 453552 (India); Schipmann, Susanne [II. Insatitute of Physics and JARA-FIT, RWTH Aachen University, 52056 Aachen (Germany); Mathur, Aakash; Pal, Dipayan [Discipline of Metallurgy Engineering and Materials Science, Indian Institute of Technology Indore, Indore 453552 (India); Sengupta, Amartya [Department of Physics, Indian Institute of Technology Delhi, Delhi 110016 (India); Klemradt, Uwe [II. Insatitute of Physics and JARA-FIT, RWTH Aachen University, 52056 Aachen (Germany); Chattopadhyay, Sudeshna, E-mail: sudeshna@iiti.ac.in [Discipline of Metallurgy Engineering and Materials Science, Indian Institute of Technology Indore, Indore 453552 (India); Discipline of Physics, Indian Institute of Technology Indore, Indore 453552 (India); Centre for Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore 453552 (India)

    2017-08-31

    Highlights: • Ultra-thin ZnO films grown on confined polymeric (polystyrene, PS) template. • XRR and GISAXS explore the surface/interfaces structure and morphology of ZnO/PS. • Insights into the growth mechanism of magnetron sputtered ZnO thin film on PS template. • Nucleated disk-like cylindrical particles are the basis of the formation of ZnO layers. • Effect of ZnO film thickness on room temperature PL spectra in ZnO/PS systems. - Abstract: The structure and morphology of ultra-thin zinc oxide (ZnO) films with different film thicknesses on confined polymer template were studied through X-ray reflectivity (XRR) and grazing incidence small angle X-ray scattering (GISAXS). Using magnetron sputter deposition technique ZnO thin films with different film thicknesses (<10 nm) were grown on confined polystyrene with ∼2R{sub g} film thickness, where R{sub g} ∼ 20 nm (R{sub g} is the unperturbed radius of gyration of polystyrene, defined by R{sub g} = 0.272 √M{sub 0}, and M{sub 0} is the molecular weight of polystyrene). The detailed internal structure, along the surface/interfaces and the growth direction of the system were explored in this study, which provides insight into the growth procedure of ZnO on confined polymer and reveals that a thin layer of ZnO, with very low surface and interface roughness, can be grown by DC magnetron sputtering technique, with approximately full coverage (with bulk like electron density) even in nm order of thickness, in 2–7 nm range on confined polymer template, without disturbing the structure of the underneath template. The resulting ZnO-polystyrene hybrid systems show strong ZnO near band edge (NBE) and deep-level (DLE) emissions in their room temperature photoluminescence spectra, where the contribution of DLE gets relatively stronger with decreasing ZnO film thickness, indicating a significant enhancement of surface defects because of the greater surface to volume ratio in thinner films.

  8. Exchange bias in sputtered FeNi/FeMn systems: Effect of short low-temperature heat treatments

    Energy Technology Data Exchange (ETDEWEB)

    Savin, Peter, E-mail: peter.savin@urfu.ru [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Guzmán, Jorge [Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain); Lepalovskij, Vladimir [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Svalov, Andrey; Kurlyandskaya, Galina [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Departamento de Electricidad y Electrónica, Universidad del País Vasco (UPV/EHU), 48940 Leioa, Vizcaya (Spain); Asenjo, Agustina [Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain); Vas’kovskiy, Vladimir [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Vazquez, Manuel [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain)

    2016-03-15

    Short (5 min) post-deposition thermal treatments under magnetic field at low temperature (up to 200 °C) performed in exchange-coupled FeNi(40 nm)/FeMn(20 nm) bilayer thin films prepared by magnetron sputtering are shown to be effective to significantly modify their exchange field (from around 40 Oe down to 27 Oe) between FeNi and FeMn layers. A similar exchange field decrease was observed for the first deposited FeNi layer of the FeNi(40 nm)/FeMn(20 nm)/FeNi(40 nm) trilayer films after the same thermal treatments. The exchange field value for the second FeNi layer was not substantially changed. The X-ray diffraction patterns indicates that such a heat treatment has no effect on the grain size and crystalline texture of the films, while atomic force microscope studies reveal an increase of the surface roughness after the treatment which is more noticeable in the case of the trilayer film. Analysis of the experimental results leads us to conclude that the variations of the exchange field after heat treatment are likely caused by a modification of interfacial roughness and/or interfacial magnetic structure, but unlikely by the changes in the microstructure and/or changes of composition of the antiferromagnetic FeMn layer. - Highlights: • FeNi/FeMn bilayers and FeNi/FeMn/FeNi trilayers were prepared by magnetron sputtering. • Post-deposition heat treatments at the temperatures below 200 °C during 5 min were made. • Annealing reduces the exchange field for the first FeNi layer in trilayers. • The exchange field value for the second FeNi layer was not substantially changed. • Exchange field changes are most likely caused by a modification of interface roughness.

  9. Application of magnetron sputtering for producing bioactive ceramic ...

    Indian Academy of Sciences (India)

    Wintec

    bone tissue engineering. 45S5-coated implants exhibited greater bone ingrowth compared with HA-coated implants, and they maintained their mechanical integrity over time. (Wheeler et al 2001). And the biological performance of the BG/HA sputter coating is more excellent (Wolke et al. 2005). Zirconia (ZrO2), especially ...

  10. RF sputtering: A viable tool for MEMS fabrication

    Indian Academy of Sciences (India)

    In the present work, we report preparation of silicon dioxide, silicon nitride and piezoelec- tric ZnO films by RF sputtering process. The properties of these films relevant for MEMS applications have been evaluated. The application of these films in fabricating basic MEMS structures such as diaphragm, micro-cantilever beams ...

  11. Sputtering of solid deuterium by He-ions

    DEFF Research Database (Denmark)

    Schou, Jørgen; Stenum, B.; Pedrys, R.

    2001-01-01

    Sputtering of solid deuterium by bombardment of 3He+ and 4He+ ions was studied. Some features are similar to hydrogen ion bombardment of solid deuterium, but for the He-ions a significant contribution of elastic processes to the total yield can be identified. The thin-film enhancement is more...... pronounced than that for hydrogen projectiles in the same energy range....

  12. Sputtering of solid neon by keV hydrogen ions

    DEFF Research Database (Denmark)

    Ellegaard, Ole; Schou, Jørgen; Sørensen, H.

    1986-01-01

    Sputtering of solid Ne with the hydrogen ions H+1, H+2 and H+3 in the energy range 1–10 keV/atom has been studied by means of a quartz microbalance technique. No enhancement in the yield per atom for molecular ions was found. The results for hydrogen ions are compared with data for keV electrons...

  13. Beam optics optimization of a negative-ion sputter source

    Indian Academy of Sciences (India)

    A negative-ion sputter source has been studied in order to increase the beam intensity delivered by the Vivitron tandem injector. The aim was to characterize the influence on the beam intensity of some factors related to the configuration of the source such as the shape of the target holder, the target surface topography and ...

  14. Physicochemical model for reactive sputtering of hot target

    Energy Technology Data Exchange (ETDEWEB)

    Shapovalov, Viktor I., E-mail: vishapovalov@mail.ru; Karzin, Vitaliy V.; Bondarenko, Anastasia S.

    2017-02-05

    A physicochemical model for reactive magnetron sputtering of a metal target is described in this paper. The target temperature in the model is defined as a function of the ion current density. Synthesis of the coating occurs due to the surface chemical reaction. The law of mass action, the Langmuir isotherm and the Arrhenius equation for non-isothermal conditions were used for mathematical description of the reaction. The model takes into consideration thermal electron emission and evaporation of the target surface. The system of eight algebraic equations, describing the model, was solved for the tantalum target sputtered in the oxygen environment. It was established that the hysteresis effect disappears with the increase of the ion current density. - Highlights: • When model is applied for a cold target, hysteresis width is proportional to the ion current density. • Two types of processes of hot target sputtering are possible, depending on the current density: with and without the hysteresis. • Sputtering process is dominant at current densities less than 50 A/m{sup 2} and evaporation can be neglected. • For current densities over 50 A/m{sup 2} the hysteresis width reaches its maximum and the role of evaporation increases.

  15. Doubly Charged Ion Emission in Sputtering of Monocrystalline Fluorides

    Czech Academy of Sciences Publication Activity Database

    Lörinčík, Jan; Šroubek, Zdeněk

    2002-01-01

    Roč. 187, - (2002), s. 447-450 ISSN 0168-583X R&D Projects: GA ČR GA202/99/0881; GA AV ČR IAA1067801 Institutional research plan: CEZ:AV0Z4040901 Keywords : secondary ion emission * doubly charged * sputtering Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.158, year: 2002

  16. Transition from linear to nonlinear sputtering of solid xenon

    DEFF Research Database (Denmark)

    Dutkiewicz, L.; Pedrys, R.; Schou, Jørgen

    1995-01-01

    Self-sputtering of solid xenon has been studied with molecular dynamics simulations as a model system for the transition from dominantly linear to strongly nonlinear effects. The simulation covered the projectile energy range from 20 to 750 eV. Within a relatively narrow range from 30 to 250 e...

  17. Development of ion beam sputtering techniques for actinide target preparation

    Science.gov (United States)

    Aaron, W. S.; Zevenbergen, L. A.; Adair, H. L.

    1985-06-01

    Ion beam sputtering is a routine method for the preparation of thin films used as targets because it allows the use of a minimum quantity of starting material, and losses are much lower than most other vacuum deposition techniques. Work is underway in the Isotope Research Materials Laboratory (IRML) at ORNL to develop the techniques that will make the preparation of actinide targets up to 100 μg/cm 2 by ion beam sputtering a routinely available service from IRML. The preparation of the actinide material in a form suitable for sputtering is a key to this technique, as is designing a sputtering system that allows the flexibility required for custom-ordered target production. At present, development work is being conducted on low-activity actinides in a bench-top system. The system will then be installed in a hood or glove box approved for radioactive materials handling where processing of radium, actinium, and plutonium isotopes among others will be performed.

  18. On the microstructure and interfacial properties of sputtered nickel ...

    Indian Academy of Sciences (India)

    Administrator

    (Walker et al 1990; Johnson 1991; Fu et al 2004). For a. Ti–Ni thin film to work as micro-device, control over working temperature and compositional tuning during deposition are the prime requisites. Due to inflexibility in composition adjustment, the fabrication of the Ti–Ni thin film by sputter deposition with Ti–Ni alloy target ...

  19. Application of magnetron sputtering for producing bioactive ceramic ...

    Indian Academy of Sciences (India)

    Wintec

    Mechanical Engineering Department, Jinan Vocational College, Shandong Jinan 250103, P.R. China. MS received 9 March 2008; revised 10 September 2008. Abstract. Radio frequency (RF) magnetron sputtering is a versatile deposition technique that can produce thin, uniform, dense calcium phosphate coatings.

  20. On the microstructure and interfacial properties of sputtered nickel ...

    Indian Academy of Sciences (India)

    Administrator

    migration of adatoms. When films are sputter deposited on substrate held at higher temperature, surface migration of the adatoms with higher energy takes place. This is due to the fact that the adatoms gain additional energy apart from the kinetic energy while they reach the grow- ing film surface. This would result in the ...