Abstract: 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.

Abstract: 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.

Abstract: 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, FexTiyMAaMBb . . . (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<x?52.5, 20?y?24.5, 24.5?z?29, a>0, and b>0 in atom %, respectively.

Abstract: 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.

Abstract: Provided is a thermoelectric conversion material formed from a full Heusler alloy represented by the composition formula: Fe2+?(Ti1??M1?)1??+?(Al1??M2?)1??. 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. ? satisfies the relation: 0<??0.42, ? satisfies the relation: 0??<0.75, and ? satisfies the relation: 0??<0.5. The valence electron concentration, VEC, satisfies the relation: 5.91?VEC<6.16.

Abstract: 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.

Abstract: 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, FexTiyMAaMBb . . . (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<x?52.5, 20?y?24.5, 24.5?z?29, a>0, and b>0 in atom %, respectively.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Provided is a thermoelectric conversion material formed from a full Heusler alloy represented by the composition formula: Fe2+?(Ti1??M1?)1??+?(Al1??M2?)1??. 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, ? satisfies the relation: 0<??0.42, ? satisfies the relation: 0??<0.75, and ? satisfies the relation: 0??< 0.5. The valence electron concentration, VEC, satisfies the relation: 5.91?VEC<6.16.

Abstract: The present invention provides a thermoelectric conversion material that has low thermal conductivity and that is stable at a high temperature, and a thermoelectric conversion module using the same. The thermoelectric conversion material includes a granular base material including a semiconductor, a fine particle with a guest material distributed in the granular base material, and a binder with the guest material on a grain boundary of the granular base material. An amount of the binder is equal to or smaller than an amount of the fine particle, an amount of the granular base material is larger than a total amount of the binder and the fine particle, and the semiconductor and the guest material are in an isolated state not forming a compound by a eutectic reaction, a eutectoid reaction, a peritectic reaction, a peritectoid reaction, a monotectic reaction, or a segregation reaction.

Abstract: A thermoelectric conversion device includes a Heusler alloy film having a structure of B2 or L21 in notation of A2BC 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.

Abstract: 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.

Abstract: A thermoelectric conversion device includes a Heusler alloy film having a structure of B2 or L21 in notation of A2BC 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.

Abstract: 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.

Abstract: Provided are a thermoelectric device and a thermoelectric module having larger conversion efficiency than conventional ones. A thermoelectric device of the present invention includes a Heusler alloy material, and a pair of electrodes that takes out electromotive force according to a temperature gradient caused in the Heusler alloy material. Further, the dimensions of the Heusler alloy material are defined such that the conversion efficiency of the module is maximized according to an environment having a temperature difference, under which the Heusler alloy material is used.

Abstract: Provided is a p-type thermoelectric conversion material achieving a low environment load and low costs and having high efficiency. A thermoelectric conversion device is constituted by raw materials existing in a great amount in nature by using Fe and S as main components. Further, since FeS2 of a pyrite structure has a d orbit derived from Fe in a valence band and a high state density, high performance as the thermoelectric conversion device is implemented by adding an addition element to this material system to express a p-type semiconductor characteristic.

Abstract: A thermoelectric conversion element is provided as an element module with improved utility having an enhanced performance index and utilizing Fe2VAl type alloy thin-film under the condition of the drop in thermal conductivity. The structure of thermoelectric conversion element is comprised of a conductive buffer layer and plural repeating stages of single structures including thermoelectric conversion material layer and a conductive buffer layer, over a buffer layer formed on a substrate; and each of the thermoelectric conversion material layers is comprised of Full-Heusler alloy or Full-Heusler alloy thin film in a thickness range between 1 nm to 200 nm.

Abstract: Provided a compound catalyst allowing for substitution of a rare noble metal such as platinum, palladium and the like or reduction of costs associated with the use thereof. According to the present invention, the oxidation-reduction characteristics thereof may be controlled and catalytic effects similar to those of a noble metal or a transition metal complex may be exhibited by controlling the valence electron concentration of a compound to change the electronic occupation number of the d-band and maintaining the electronic state at the Fermi level of the electronic state identical to a noble metal or a transition metal complex.