Hitachi, Ltd.

Hitachi Metals, Ltd.

Shin Yabuuchi

Yosuke Kurosaki

Jun Hayakawa

Akinori Nishide

Jyun Hayakawa

Naoto Fukatani

Hiroyuki Yamamoto

Hiromasa Takahashi

Akio Yoneyama

Futoshi Furuta

Yuji Suwa

Masakuni Okamoto

Yuzuru Miyazaki

Tomohisa Takamatsu

Kei Hayashi

Daikoh Takamatsu

A hydrogen production apparatus including a photocatalyst and generating hydrogen from water includes a wavelength separation unit separating sunlight by wavelength, an infrared light conversion unit converting infrared light separated by the wavelength separation unit to visible light, and an ultraviolet light conversion unit converting ultraviolet light separated by the wavelength separation unit to visible light.

Hydrogen production apparatus

The present invention improves the performance of a thermoelectric conversion material and a thermoelectric conversion module. A thermoelectric conversion material has a mother phase containing a chimney ladder type compound comprising a first element of groups 4 to 9 and a second element of groups 13 to 15 and an additive phase existing at a grain boundary of the mother phase, the mother phase contains a third element to change a lattice constant of the chimney ladder type compound, and the additive phase contains the second element.

Thermoelectric conversion material and thermoelectric conversion module

Provided are a p-type thermoelectric conversion material, a thermoelectric conversion module, and a method of manufacturing a p-type thermoelectric conversion material that are capable of obtaining high thermoelectric conversion characteristics. The p-type thermoelectric conversion material has a full Heusler alloy having a composition represented by the following General Formula (1) and has a relative density of 85% or more, FeTiMAMB. . . (1), wherein in Formula (1), MA is one element selected from the group consisting of Si, Sn, and Ge, MB is one element selected from the group consisting of Al, Ga, and In, and x, y, a, and b are numbers set so that x+y+a+b=100, a+b=z, 50&#x3c;x&#x2264;52.5, 20&#x2264;y&#x2264;24.5, 24.5&#x2264;z&#x2264;29, a&#x3e;0, and b&#x3e;0 in atom %, respectively.

P-type thermoelectric conversion material, thermoelectric conversion module, and method of manufacturing p-type thermoelectric conversion material

Provided is a thermoelectric conversion material formed from a full Heusler alloy represented by the composition formula: Fe(TiM1)(AlM2). M1 represents at least one element selected from the group consisting of V, Nb and Ta, and M2 represents at least one element selected from the group consisting of Group 13 elements except for Al and Group 14 elements. &#x3b1; satisfies the relation: 0&#x3c;&#x3b1;&#x2264;0.42, &#x3b2; satisfies the relation: 0&#x2264;&#x3b2;&#x3c;0.75, and &#x3b4; satisfies the relation: 0&#x2264;&#x3b4;&#x3c;0.5. The valence electron concentration, VEC, satisfies the relation: 5.91&#x2264;VEC&#x3c;6.16.

Thermoelectric conversion material

A thermoelectric conversion material includes a matrix phase configured from a semiconductor. A first grain-boundary phase and a second grain-boundary phase are provided at a grain boundary of the matrix phase. The first grain-boundary phase is configured from a material which does not form a compound with the matrix phase by a eutectic reaction, a eutectoid reaction, a peritectic reaction, a peritectoid reaction, an eccentric reaction, or a segregation reaction. The second grain-boundary phase is configured from a material having resistance which is lower than that of the matrix phase or the first grain-boundary phase. A ratio of a volume of the second grain-boundary phase to a volume of the first grain-boundary phase is smaller than 1.

The present invention aims at providing a thermoelectric conversion module with low toxicity, which exhibits conversion efficiency equivalent to that of BiTe. The thermoelectric conversion module of the present invention employs a full Heusler alloy as the material for forming the P-type thermoelectric conversion unit and the N-type thermoelectric conversion unit. The material for forming the N-type thermoelectric conversion unit contains at least any one of Fe, Ti, and Si and Sn.

Thermoelectric conversion module

In order to provide a thermoelectric conversion element which has a high Seebeck coefficient, a low thermal conductivity, and a high performance, even if the material system that has a low environmental load and can reduce the cost is used, the thermoelectric conversion element in which lattice points are classified into two or more kinds (A site and B site), lattices of which the kinds are different are connected to each other, the numbers of lattices of which the kinds are different are different (A site: 2, and B site: 1), and a lattice structure is configured by arranging nanoparticles or semiconductor quantum dots, includes areas of which conductivity types are different.

Thermoelectric conversion element and thermoelectric conversion module

A thermoelectric conversion device includes a Heusler alloy film having a structure of Bor Lin notation of ABC and a pair of electrodes on the Heusler alloy film to output an electromotive force generated by a thermal gradient in the Heusler alloy film. The thermoelectric conversion device further includes an electrode for applying an electric field or a voltage to the Heusler alloy film to increase and control an electric conductivity and a Seebeck coefficient S of the Heusler metal film. The device can control to increase an electric conductivity and Seebeck coefficient S by applying an electric field or a voltage through an insulation film to the Heusler alloy film. The device may have a shared connection to select one of outputs of a plurality of thermoelectric conversion devices arranged in a matrix or increase an electromotive force as an output.

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Tokyo, Japan

Shin Yabuuchi