Tokuyama Corporation

Tokyo University of Agriculture and Technology

National University Corporation Tokyo University of Agriculture and Technology

Hiroyuki Yanagi

Kenji Fukuta

Kazuya Takada

Toru Nagashima

Shin Watanabe

Teruhiko Nawata

Akinori Koukitu

Yoshinao Kumagai

Takenori Isomura

Tsuguo Fukuda

Toru Kinoshita

Hiromasa Yamamoto

Hiroaki Taira

Masayuki Fukuda

Hiroshi Inoue

Hidetaka Miyazaki

Kazuyuki Sadasue

Kazuya Ibaragi

Yuki Watahiki

Ken Yasumura

Reiko Okayama

Yasunori Hirata

Eiichi Nishijima

Manabu Harada

Keisuke Kondo

Nobuyuki Kuramoto

Shinichi Nitta

Harumasa Ito

Isao Yamaga

A method for producing an AlN single crystal substrate, the method including: i) preparing a first base substrate consisting of a first AlN single crystal; ii) growing a first AlN single crystal layer over a main face of the first base substrate, to obtain a layered body; iii) cutting the first MN single crystal layer of the layered body, to separate the layered body into a second base substrate and a first part of the first AlN single crystal layer, the second base substrate including the first base substrate and a thin film layered thereon, the thin film being a second part of the first AlN single crystal layer; iv) polishing a surface of the thin film, to obtain a third base substrate consisting of a second AlN single crystal; and v) growing a second AlN single crystal layer over the polished surface of the third base substrate.

Method for producing aluminum nitride single crystal substrate

Disclosed is a membrane for polymer electrolyte fuel cells, which is composed of a hydrocarbon anion-ex-change resin membrane wherein an anion-exchange group is covalently bonded to a hydrocarbon resin, and an adhesive layer formed on at least one side of the hydrocarbon anion-exchange resin membrane. The membrane for polymer electrolyte fuel cells is characterized in that the adhesive layer is made of an anion-exchange resin having a Young's modulus of 1-1000 MPa.

Separation membrane for solid polymer fuel cell and separation membrane-catalyst electrode assembly

A power generation system includes an alkaline fuel cell provided with an electrolyte membrane which is an anion exchange membrane and a pair of electrodes (an anode and a cathode) arranged on the both sides of the electrolyte membrane. The alkaline fuel cell can generate an electric power by supplying a fuel gas and an oxidizing agent gas to the anode side and the cathode side, respectively. The power generation system uses a hydrogen gas containing a basic compound such as ammonia as the fuel gas to be supplied to the anode side.

Power generation system using an alkaline fuel cell and fuel gas for alkaline fuel cells used in the system

There is provided a method capable of obtaining an aluminum-based group III nitride crystal layer having a smooth surface and high crystallinity by employing only HVPE in which inexpensive raw materials can be used to reduce production costs and high-speed film formation is possible without employing MOVPE. To produce a group III nitride crystal by HVPE comprising the step of growing a group III nitride crystal layer by vapor-phase growth on a single crystal substrate by contacting the heated single crystal substrate with a raw material gas containing a group III halide and a compound having a nitrogen atom, the group III nitride crystal is grown by vapor-phase growth on the single crystal substrate heated at a temperature of 1,000&#xb0; C. or more and less than 1,200&#xb0; C. to form an intermediate layer and then, a group III nitride crystal is further grown by vapor-phase growth on the intermediate layer on the substrate heated at a temperature of 1,200&#xb0; C. or higher.

Method of producing a group III nitride crystal

A stable, high output is obtained with an anion exchange membrane-type fuel cell that generates electricity when air is supplied. An operating method for an anion exchange membrane-type fuel cell includes an anion exchange membrane electrode assembly for which an anode is joined to one surface of a anion exchange membrane and a cathode is joined to the other surface, and air is supplied to the cathode, wherein air with a reduced carbon dioxide concentration in the atmosphere is supplied to the cathode by a low carbon dioxide air supply system that supplies air with the reduced carbon dioxide concentration to the cathode.

Operating method of anion-exchange membrane-type fuel cell

Disclosed is a solid polymer electrolyte fuel cell membrane comprising an anion exchange membrane that contains a hydrocarbon-based anion exchange resin, wherein the water permeability at 25&#xb0; C. is 1400 g mhror greater, the anion exchange capacity is 0.2 to 5.0 mmol&#xb7;g, the percentage of water content at 25&#xb0; C. is 7% by weight or greater, and the thickness is 3 to 50 &#x3bc;m. It is especially preferable as a solid polymer electrolyte fuel cell membrane when said anion exchange membrane is an ion exchange membrane with a 5 to 15 &#x3bc;m-thick porous membrane substrate, wherein the voids in said porous membrane are filled with a hydrocarbon-based anion exchange resin.

Solid polymer electrolyte fuel cell membrane with anion exchange membrane

An anion-exchange membrane having quaternary ammonium groups or quaternary phosphonium groups wherein halogen ions serve as the counter ions is obtained. Rather than being subjected to ion exchange with an OH-type membrane using a toxic substance such as sodium hydroxide, the halogen-type anion exchange membrane is brought into contact with a carbonate solution and/or bicarbonate solution to directly obtain an anion exchange membrane where at least some of the counterions of the quaternary ammonium groups or quaternary phosphonium groups are COand/or HCO.

Method for producing an anion-exchange membrane for a solid polymer electrolyte type fuel cell

This invention provides a p-type group III nitride semiconductor, with good p-type properties, having a composition expressed by AlGaInN in which each of X, Y and Z indicates a rational number satisfying a relationship of X+Y+Z=1.0, even if Al content is as high as 1.0&#x3e;X&#x2267;0.5. It is achieved that a proportion of a hole concentration at 30&#xb0; C. to an acceptor impurity atom concentration is 0.001 or more in the p-type group III nitride semiconductor of the invention, by doping acceptor impurity atoms such as Mg in concentration of 5&#xd7;10to 1&#xd7;10cmusing the method, for example, MOCVD with attention not to incorporate an impurity atom other than the acceptor impurity atom or not to form dislocation in the crystal when producing the group III nitride semiconductor expressed by the above composition.

P-type group III nitride semiconductor and group III nitride semiconductor element

Disclosed is a process for producing a diaphragm for a fuel cell comprising a modified anion exchange membrane that substantially maintains durability and hydroxide ion conductivity as an electrolyte membrane and has improved resistance to methanol permeation. The process is characterized by comprising the step of impregnating at least one side of a crosslinked hydrocarbon anion exchange membrane with a polymerizable acidic compound having a weight average molecular weight of not less than 700 and less than 8000, provided that, when the acid site in the compound has been neutralized with a counter cation, the weight of the counter cation is subtracted from the molecular weight, and polymerizing the polymerizable acidic compound.

Separation membrane for fuel cell and production method thereof

This invention provides a self supporting substrate which consists of a n-type conductive aluminum nitride semiconductor crystal and is useful for manufacturing the vertical conductive type AlN semiconductor device. The n-type conductive aluminum nitride semiconductor crystal, by which the self supporting substrate is made up, contains Si atom at a concentration of 1&#xd7;10to 5&#xd7;10cmis substantially free of halogen atoms and substantially does not absorb the light having the energy of not more than 5.9 eV. The self supporting substrate can be obtained by a method comprising the steps of forming an AlN crystal layer on a single crystal substrate such as a sapphire by the HVPE method, preheating the obtained substrate having the AlN crystal layer to a temperature of 1,200&#xb0; C. or more, forming a second layer consisting of the n-type conductive aluminum nitride semiconductor crystal is formed on the AlN crystal layer in high rate by the HVPE method and separating the second layer from the obtained laminate.

n-Type conductive aluminum nitride semiconductor crystal and manufacturing method thereof

A metal fluoride single crystal pulling apparatus that upward pulling initiation through termination, in the state of shallow melt capable of highly effective inhibition of scatterer formation, can perform stable growth of single crystal and can suppress any mixing of air bubbles and occurrence of crystal break during crystal growth, etc; and a process for producing a metal fluoride single crystal therewith. As a crucible for accommodating a melt of raw metal fluoride, use is made of a double structured crucible composed of an outer crucible and an inner crucible. In the upward pulling of single crystal, the accommodation depth of inner crucible relative to the outer crucible is increased in accordance with any decrease of melt accommodated in the inner crucible according to the growth of single crystal, so that the melt accommodated in the outer crucible is fed into the inner crucible to thereby maintain the amount of melt accommodated in the inner crucible within a given range. Further, at the position of an opening that upward opens any gap space between an external surface of outer crucible and an internal surface of inner crucible, or an interstice, situated below the opening, between a side wall internal surface of outer crucible and a side wall external surface of inner crucible, there is disposed a cutoff member that cuts off at least part of the position.

Process for producing metal fluoride single crystal

A method of producing a group III nitride such as aluminum nitride, comprising the step of reacting a group III halide gas such as aluminum trichloride gas with a nitrogen source gas such as ammonia gas in a growth chamber to grow a group III nitride on a substrate held in the growth chamber, wherein the method further comprises premixing together the group III halide gas and the nitrogen source gas to obtain a mixed gas and then introducing the mixed gas into the growth chamber without forming a deposit in the mixed gas substantially to be reacted each other. For the growth of a group III nitride such as an aluminum-based group III nitride by HVPE, there are provided a method of producing the group III nitride having as high quality as that obtained by the method of the prior art at a high yield and an apparatus used in the method.

Method and apparatus for producing group III nitride

A single crystal of alkaline earth metal fluoride is produced by a single crystal pulling method, has a straight barrel part diameter of not less than 17 cm, preferably has a straight barrel part length of not less than 5 cm, and has a light transmittance, as measured at a wavelength of 632.8 nm, of not less than 80%, preferably 90 to 98%. Further, the main crystal growth plane of the single crystal is the {111} plane or the {100} plane. The single crystal of alkaline earth metal fluoride has a large diameter as described above, and in spite that it is in an as-grown state, the peripheral surface is not opaque and the visible light transmittance is high. Therefore, evaluation of bubbles or inclusions in the crystal becomes feasible without performing complicated machining of the crystal, and from the single crystal, a large-sized optical material having advantageous properties such as high quality and high uniformity can be cut out.

As-grown single crystal of alkaline earth metal fluoride

A single crystal pulling apparatus for a metal fluoride comprising a crucible provided in a chamber for filling with a molten solution of a single crystal material, a melting heater provided to surround the crucible, a vertically movable single crystal pulling bar for attaching a seed crystal on a tip thereof for coming in contact with the molten solution of the single crystal material in the crucible, a heat insulating wall provided in the chamber to surround at least a peripheral side portion of a single crystal pulling region in an upper part of the crucible, a ceiling board for closing an opening portion of an upper end in an upper part of the heat insulating wall, and a single crystal pulling chamber surrounded by the heat insulating wall and the ceiling board, wherein the ceiling board is provided with at least an inserting hole for inserting the single crystal pulling bar, and wherein a coefficient of thermal conductivity in a direction of a thickness of the ceiling board is 1000 to 50000 W/m&#xb7;K.

Single crystal pulling apparatus for a metal fluoride

A memberane sensitive to anions is obtained by forming into a membrane either a composition comprising an onium salt compound such as trioctylmethylammonium chloride or tetraoctylammonium bromide, and an aromatic boric diester compound such as (p-alkyloxy)phenyl borate, or a composition which comprises these two ingredients and a membrane-forming polymer such as polyvinyl chloride or polystyrene, and may further contain a fat-soluble anion salt such as tetraphenyl borate. This membrane can yield an ion-selective electrode which permits hydrogencarbonate ions contained in body fluids to be rapidly determined with high sensitivity and high selectivity and which has a long life.

Growing community of inventors

Shunan, Japan

Hiroyuki Yanagi