Showing papers on "Graphene oxide paper published in 2002"

Nano-scaled graphene plates

Abstract: A nano-scaled graphene plate material and a process for producing this material. The material comprises a sheet of graphite plane or a multiplicity of sheets of graphite plane. The graphite plane is composed of a two-dimensional hexagonal lattice of carbon atoms and the plate has a length and a width parallel to the graphite plane and a thickness orthogonal to the graphite plane with at least one of the length, width, and thickness values being 100 nanometers or smaller. The process for producing nano-scaled graphene plate material comprises the steps of: a). partially or fully carbonizing a precursor polymer or heat-treating petroleum or coal tar pitch to produce a polymeric carbon containing micron- and/or nanometer-scaled graphite crystallites with each crystallite comprising one sheet or a multiplicity of sheets of graphite plane; b). exfoliating the graphite crystallites in the polymeric carbon; and c). subjecting the polymeric carbon containing exfoliated graphite crystallites to a mechanical attrition treatment to produce the nano-scaled graphene plate material.

Highly reliable gate oxide and method of fabrication

Abstract: An ultra-thin gate oxide layer of hafnium oxide (HfO2) and a method of formation are disclosed. The ultra-thin gate oxide layer of hafnium oxide (HfO2) is formed by a two-step process. A thin hafnium (Hf) film is first formed by thermal evaporation at a low substrate temperature, after which the thin hafnium film is radically oxidized using a krypton/oxygen (Kr/O2) high-density plasma to form the ultra-thin gate oxide layer of hafnium oxide (HfO2). The ultra-thin gate oxide layer of hafnium oxide (HfO2) formed by the method of the present invention is thermally stable in contact with silicon and is resistive to impurity diffusion at the HfO2/silicon interface. The formation of the ultra-thin gate oxide layer of hafnium oxide (HfO2) eliminates the need for a diffusion barrier layer, allows thickness uniformity of the field oxide on the isolation regions and, more importantly, preserves the atomically smooth surface of the silicon substrate.

Semiconducting oxide nanostructures

Abstract: Nanostructures and methods of fabricating nanostructures are disclosed. A representative nanostructure includes a substrate having at least one semiconductor oxide. In addition, the nanostructure has a substantially rectangular cross-section. A method of preparing a plurality of semiconductor oxide nanostructures that have a substantially rectangular cross-section from an oxide powder is disclosed. A representative method includes: heating the oxide powder to an evaporation temperature of the oxide powder for about 1 hour to about 3 hours at about 200 torr to about 400 torr in an atmosphere comprising argon; evaporating the oxide powder; and forming the plurality of semiconductor oxide nanostructures.

Tubular titanium oxide particles, method for preparing the same, and use of the same

Abstract: A method for preparing tubular titanium oxide particles, characterized in that a water sol which comprises water and, dispersed therein, (i) titanium oxide particles and/or (ii) titanium oxide based composite oxide particles comprising titanium oxide and an oxide except titanium oxide, and have an average particle diameter of 2 to 100 nm is subjected to a hydrothermal treatment in the presence of an alkali metal hydrooxide. The product of the hydrothermal treatment is optionally subjected to a reduction treatment (including nitriding treatment). A tubular titanium oxide particles prepared by the above method are useful as a catalyst, a catalyst carrier, an adsorbent, a photocatalyst, a cosmetic material, an optical material, an optoelectric conversion material and the like. In particular, the particles exhibit very excellent effect when used in applications of a semiconductor film for a photoelectrical cell and of a photocatalyst.

Method of fabricating an oxide layer on a silicon carbide layer utilizing an anneal in a hydrogen environment

Abstract: Silicon carbide structures are fabricated by fabricating a nitrided oxide layer on a layer of silicon carbide and annealing the nitrided oxide layer in an environment containing hydrogen. Such a fabrication of the nitrided oxide layer may be provided by forming the oxide layer in at least one of nitric oxide and nitrous oxide and/or annealing an oxide layer in at least one of nitric oxide and nitrous oxide. Alternatively, the nitrided oxide layer may be provided by fabricating an oxide layer and fabricating a nitride layer on the oxide layer so as to provide the nitrided oxide layer on which the nitride layer is fabricated. Furthermore, annealing the oxide layer may be provided as a separate step and/or substantially concurrently with another step such as fabricating the nitride layer or performing a contact anneal. The hydrogen environment may be pure hydrogen, hydrogen combined with other gases and/or result from a hydrogen precursor. Anneal temperatures of 400 °C or greater are preferred.

Interfacial oxide layers at the metal–oxide phase boundary

Abstract: The nature of oxide phases at metal–oxide interfaces, i.e. of oxide layers in the proximity of a metal surface, is assessed by critically examining the available data in the literature. The data reveal a trend towards the formation of reduced oxide phases with lower oxidation states in the vicinity of the interface with a metal. The physical origin of these interface-stabilized oxide layers is discussed and the possible causes include strong metal–metal bonding, high oxygen affinity of the substrate metal, reduction of the interfacial strain, and the stability of two-dimensional oxide phases.

Graphite article having predetermined anisotropic characteristics and process therefor

Abstract: The invention presented is a graphite article having predetermined anisotropic characteristics, as well as a process for preparing the article. More particularly, the article is prepared by a process involving determining the desired anisotropic characteristics for a finished flexible graphite article (FIg. 1a); intercalating and then exfoliating flakes of graphite to form exfoliated graphite particles; forming a substrate graphite article by compressing the exfoliated graphite particles into a coherent article formed of graphene layers; and producing a controlled directional alignment of the graphene layers in the substrate graphite article to provide a finished graphite article having the desired anisotropic ratio. The article may be embossed and the relative amount of structure in an embossed flexible graphite wall can and will lead to differing anisotropic properites. The embossing apparatus (10) comprises two opposed elements (20) and (30).

Sputtering target and transparent electroconductive film

Abstract: The present invention is directed to a sputtering target which inhibits formation of nodules during sputtering so as to form a transparent conductive film, thereby reliably forming the film, and to a transparent conductive film exhibiting excellent etching processability. The sputtering target is formed of a specific sintered metal oxide product composed of indium oxide, gallium oxide, and zinc oxide (1) or a specific sintered metal oxide product composed of indium oxide, gallium oxide, and germanium oxide (2).

Composite oxide powder, catalyst and process for producing the same

Abstract: Composite oxide powder has a large specific surface area and a large pore volume even after a high-temperature durability test, without losing oxygen storage ability of a single metal oxide. In this composite oxide powder, a first metal oxide having oxygen storage ability is held as ultrafine particles in the form of islands by a second metal oxide which is different from the first metal oxide, pore volume is not less than 2 cc/g and the first metal oxide particles have a diameter of not more than 30 nm even after subjected to high temperature of 900° C. or more. Since the first metal oxide particles are held in the form of islands by the second metal oxide particles, separated from each other and suppressed from contacting each other, the first metal oxide particles hardly grow granularly.

Transistor with layered high-K gate dielectric and method therefor

Abstract: A transistor device has a gate dielectric with at least two layers in which one is hafnium oxide and the other is a metal oxide different from hafnium oxide. Both the hafnium oxide and the metal oxide also have a high dielectric constant. The metal oxide provides an interface with the hafnium oxide that operates as a barrier for contaminant penetration. Of particular concern is boron penetration from a polysilicon gate through hafnium oxide to a semiconductor substrate. The hafnium oxide will often have grain boundaries in its crystalline structure that provide a path for boron atoms. The metal oxide has a different structure than that of the hafnium oxide so that those paths for boron in the hafnium oxide are blocked by the metal oxide. Thus, a high dielectric constant is provided while preventing boron penetration from the gate electrode to the substrate.

Organic luminescence device and its production method

Abstract: An organic luminescence device uses a substrate with a gas-barrier film in which a gas-barrier film containing an amorphous oxide and at least two kinds of oxides selected from the group consisting of boron oxide, phosphorus oxide, sodium oxide, potassium oxide, lead oxide, titanium oxide, magnesium oxide, and barium oxide is formed on a substrate. The selected two kinds of oxides are a combination of an oxide of an element having a large atomic radius and an oxide of an element having a small atomic radius. The substrate is made of glass or plastic. As a result, the organic luminescence device using a substrate excellent in gas-barrier capability to prevent the infiltration of oxygen, water vapor, etc. from outside is provided.

Process for forming silicon oxide material

Abstract: A thin layer of silicon oxide is formed by cyclic introduction of a silicon-containing precursor gas and an oxidizing gas separated by an intervening purge step. The resulting thin oxide layer enables subsequent conventional CVD of oxide to produce a more uniform deposited oxide layer over nonhomogenous surfaces, for example the silicon nitride mask/thermal oxide liner surfaces created during fabrication of shallow trench isolation structures.

Oxide interface and a method for fabricating oxide thin films

Abstract: An oxide interface and a method for fabricating an oxide interface are provided. The method comprises forming a silicon layer and an oxide layer overlying the silicon layer. The oxide layer is formed at a temperature of less than 400° C. using an inductively coupled plasma source. In some aspects of the method, the oxide layer is more than 20 nanometers (nm) thick and has a refractive index between 1.45 and 1.47. In some aspects of the method, the oxide layer is formed by plasma oxidizing the silicon layer, producing plasma oxide at a rate of up to approximately 4.4 nm per minute (after one minute). In some aspects of the method, a high-density plasma enhanced chemical vapor deposition (HD-PECVD) process is used to form the oxide layer. In some aspects of the method, the silicon and oxide layers are incorporated into a thin film transistor.

Effects of Hydrogen Introduction on Electrical and Optical Properties of Cd-doped Ge Oxide and Zn Oxide Thin Films

Abstract: Cadmium-doped Ge oxide and Zn oxide thin films were deposited by RF magnetron sputtering. The electrical and optical properties of these films were investigated. All deposited films except for highly Cd-doped Ge oxide were transparent to visible light. Hydrogen introduction reduced the resistivity of the films, although the optical transmittance for visible light did not change significantly. The enhancement of conductivity could be attributed to the increase in carrier density by the hydrogen introduction.

Oxide superconducting conductor and its production method

Abstract: The object of the present invention is to provide an oxide superconducting conductor having superior strength and superconductor characteristics, and its production method. In order to achieve the above object, the present invention provides an oxide superconducting conductor having an oxide superconductor layer obtained by a method in which a raw material gas of an oxide superconductor is chemically reacted on a base material for forming an oxide superconductor provided with an Ag layer having a rolling texture formed on at least one side of a base material containing Ag base material or other base metal, a diffusion layer in which Cu is diffused in Ag is formed on the surface layer of the oxide superconductor layer side of the above base material, and the above oxide superconductor layer is formed on the above diffusion layer; and, an oxide superconducting conductor comprising the sequential generation of a plurality of layers of oxide superconductor containing Cu by CVD on an Ag layer of a base material for forming an oxide superconducting conductor provided with an Ag layer having a rolling texture formed on at least one side of an Ag base material or other base metal, and among the above plurality of oxide superconductor layers, the Cu content of the oxide superconductor layer immediately above the base material is made to have a higher concentration than the Cu content of the other oxide superconductor layers.

Characterization of annealing effects of low temperature chemical vapor deposition oxide films as application of 4H-SiC metal–oxide–semiconductor devices

Abstract: The characteristics of charge trapping and interface states for low temperature chemical vapor deposition (LTCVD) oxide formed on 4H-SiC as carbon-free gate oxide has been studied. Observation of a large flatband voltage shift indicated the presence of many negative oxide charges in the as-deposited LTCVD oxide. Heat treatment was carried out to improve the quality of the LTCVD oxide in various conditions. Interface state density, flatband voltage, and effective oxide charge were decreased with the heat treatment. The heat treatment also greatly improved charge trapping characteristics against electron injection.

Method for producing metal oxide particle and method for forming metal oxide film

Abstract: PROBLEM TO BE SOLVED: To provide a new method for producing metal oxide particle and a method for forming metal oxide film which enable metal oxide particle or metal oxide film of multiple metal oxide or solid solution oxide containing metal atoms of two kinds or more to be easily and stably obtained in the state that the contained metal atoms have excellent uniformity. SOLUTION: This method for producing a first metal oxide particle is a method of preparing the metal oxide particle by using metal carboxylates of two kinds or more which are different in metal atoms contained therein and alcohol as starting materials and, therein, features that the preparation is performed under such a temperature that the reaction rates of the metal carboxylates of two kinds or more are substantially the same. COPYRIGHT: (C)2003,JPO

The Cycling Performance of Graphite Electrode Coated with Tin Oxide for Lithium Ion Battery

Abstract: Tin oxide was coated on graphite particle by sol-gel method and an electrode with this material having microcrystalline structure for lithium ion battery was obtained by heat treatment in the range . The content of tin oxide was controlled within the range of . The discharge capacity increased with the content of tin oxide and also initial irreversible capacity increased. The discharge capacity of tin oxide electrode showed more than 350 mAh/g at the initial cycle and 300 mAh/g after the 30th cycle in propylene carbonate(PC) based electrolyte whereas graphite electrode without surface modification showed 140 mAh/g. When the charge and discharge rate was changed from C/5 to C/2, The discharge capacity of tin oxide and graphite electrode showed of initial capacity, respectively. It has been considered that such an enhancement of electrode characteristics was caused because lithium passive film formed from the reaction between tin oxide and lithium ion prevented the exfoliation of graphite electrode and also reduced tin enhanced the electrical conduction between graphite particles to improve the current distribution of electrode.

Tubular titanium oxide particles and process for preparing same

Abstract: The process for preparing tubular titanium oxide particles comprises subjecting a water dispersion sol, which is obtained by dispersing (i) titanium oxide particles and/or (ii) titanium oxide type composite oxide particles comprising titanium oxide and an oxide other than titanium oxide in water, said particles having an average particle diameter of 2 to 100 nm, to hydrothermal treatment in the presence of an alkali metal hydroxide. After the hydrothermal treatment, reduction treatment (including nitriding treatment) may be carried out. The tubular titanium oxide particles obtained in this process are useful as catalysts, catalyst carriers, adsorbents, photocatalysts, decorative materials, optical materials and photoelectric conversion materials. Especially when the particles are used for semiconductor films for photovoltaic cells or photocatalysts, prominently excellent effects are exhibited.

Effect of Transparent Conductive Oxide Stability on CdS/CdTe Solar Cell performance

Abstract: Thin film CdS/CdTe solar cells fabricated on SnO2:F-coated glass have been found to have higher efficiencies than similar cells produced on indium-tin oxide (ITO) and tin oxide layer on indium-tin oxide (ITO/SnO2)-coated glass substrate. The transmission measurements revealed that SnO2:F was the most stable transparent conductive oxide.

Process for etching bismuth-containing oxide films

Abstract: A process is described for etching oxide films containing at least one bismuth-containing oxide, in particular a ferroelectric bismuth-containing mixed oxide. A substrate onto which at least one oxide film containing at least one bismuth-containing oxide has been applied is provided. An etching solution containing from 2 to 20% by weight of a fluoride ion donor, from 15 to 60% by weight of nitric acid and from 20 to 83% by weight of water is brought into contact with the substrate so that the etching solution can react with the oxide film. The etching solution is removed from the substrate. The etching solution is also used in a process for structuring bismuth-containing oxide films.

Metal oxide film and its use

Abstract: PROBLEM TO BE SOLVED: To provide a film being a hydroxyl-containing metal oxide film and having such bioactivity as to induce the formation of nuclei of a calcium phosphate when it is formed on the surface of an artificial bone material (even a plastic) with high bonding strength to form a product and the product is embedded in an environment within the living body and to provide a composite material using the film. SOLUTION: The metal oxide film comprises a porous structure composed of an aggregate of island metal oxide particles of a size with a mean size of 10-50nm and a height of 10-100 nm. The metal oxide film contains a metal oxide which is a complex oxide of titanium oxide, silica, and zirconium oxide and having a composition (molar ratio) of 0.3 to 0.1 SiO 2 , 0.2 to 0.03 TiO 2 , and 0.9 to 0.5. In the metal oxide film, the compound oxide contains niobium oxide, tin oxide, tantalum oxide, potassium oxide, hafnium oxide, and alumina instead of or together with the titanium oxide. The composite material comprises a substrate and the metal oxide film formed thereon. COPYRIGHT: (C)2004,JPO

Process for producing thin oxide film and production apparatus

Abstract: A process for producing a thin oxide film which comprises adsorbing or depositing an oxide-forming material onto a substrate and then forming an oxide, wherein water in a liquid state is used for forming the thin oxide film. The process takes advantage of intact merits of the ALD method and eliminates a drawback of the method that impurities are apt to remain in the oxide film formed. Thus, a thin oxide film reduced in impurity concentration is obtained.

A Semiconductor Nano-Patterning Approach Using AFM-Scratching Through Oxide Thin Layers

Abstract: : AFM-scratching was performed through thin oxide layer which was either a native oxide layer (1.5 - 2 nm thick) or a thermal oxide layer (10 nm thick). Due to their insulating properties, the SiO2 films act as masks for the metal electrochemical deposition. In the scratched openings copper deposition can take place selectively and thus nano-scale metal lines could be successfully plated onto the p-type silicon substrates. Using particularly, if sufficiently thick thermal oxide has advantages over the native oxide, it allows a H-termination of the Si within the grooves (HF treatment) without eliminating the oxide layer on the rest of the surface.

Surface Chemical Modifications of Nano-Titanium Oxide and its Applications in Coating

Abstract: An effective surface chemical modification method of nano-titanium oxide was developed and various properties of surface modified nano-titanium oxide were measured. Compared with normal titanium oxide and unmodified nano-titanium oxide, surface modified nano-titanium oxide could increase salts spray resistance and feasibility of epoxy coatings.

TUBULAR TITANIUM OXIDE PARTICLESc METHOD FOR PREPARING THE SAMEc AND USE OF THE SAME

Abstract: The process for preparing tubular titanium oxide particles according to the present invention comprises subjecting a water dispersion sol, which is obtained by dispersing (i) titanium oxide particles and/or (ii) titanium oxide type composite oxide particles comprising titanium oxide and an oxide other than titanium oxide in water, said particles having an average particle diameter of 2 to 100 nm, to hydrothermal treatment in the presence of an alkali metal hydroxide. After the hydrothermal treatment, reduction treatment (including nitriding treatment) may be carried out. The tubular titanium oxide particles obtained in this process are useful as catalysts, catalyst carriers, adsorbents, photocatalysts, decorative materials, optical materials and photoelectric conversion materials. Especially when the particles are used for semiconductor films for photovoltaic cells or photocatalysts, prominently excellent effects are exhibited.

Oxide superconductor layer and its production method

Abstract: The object of the present invention is to provide an oxide superconductor having superior strength and superconductor characteristics, and its production method. In order to achieve the above object, the present invention provides an oxide superconductor layer (d) obtained by a method in which a raw material gas of an oxide superconductor is chemically reacted on a base material provided with an Ag layer (b) having a rolling texture formed on at least one side of a base material, a diffusion layer (c) in which Cu is diffused in Ag is formed on the surface of the above base material, and the above oxide superconductor layer is formed on the above diffusion layer; furthermore, an oxide superconductor comprising the sequential generation of a plurality of layers of oxide superconductor containing Cu by CVD on a base material provided with an Ag layer (25) having a rolling texture formed on at least one side of a base material, whereby the Cu content of the oxide superconductor layer (22a) immediately above the base material is made to have a higher concentration of Cu than the other oxide superconductor layers (22b,22c).

Automotive exhaust particle filter has nitrate-forming coating applied to porous substrate

Abstract: An internal combustion engine has an exhaust filter that oxidizes trapped particles. The filter is coated with a nitrate-forming substance. The coating is a silver-based compound e.g. Ag, Ag2O, AgOH, AgNO3, AgCO3 or a mixture of these, including alkaline metals, alkaline earth metals, rare earths, or a mixture of these. The coating is applied to a finely-pored base. The coating is in elemental form, or as an oxide, hydroxide, carbonate or nitrate. The porous substrate is zirconium oxide, zirconium oxide with La, aluminum oxide, Mg-Al mixed oxides, La-aluminum oxide, Ceroxide, Titanium oxide, silicon oxide, Si-Al mixed oxide, a zeolite, or a mixture of these.