Abstract: A photoexcitable material includes: a solid solution of MN (where M is at least one of gallium, aluminum and indium) and ZnO, wherein the photoexcitable material includes 30 to 70 mol % ZnO and has a band gap energy of 2.20 eV or less.

Abstract: An oxygen generating electrode includes a conductive layer; a photocatalyst layer; and a light absorption. The light-absorbing layer arranged between the conductive layer and the photocatalyst layer. The light-absorbing layer is formed of one or a plurality of perovskite-type films, and each of the films contains tin (Sn), oxygen (O), sulfur (S), and one or more elements selected from Group 1 or Group 2 of the periodic table of elements. Each of the films formed by doping S for substituting an O site is set so that a band gap takes a predetermined value in a range between 0 eV to 4 eV.

Abstract: A photochemical electrode includes: an electrically conductive layer; and a photoexcitation material layer provided over the electrically conductive layer and including a photoexcitation material, wherein the photoexcitation material layer is one of a first photoexcitation material layer in which a potential of the conduction band minimum decreases from a second surface opposite to a first surface on the side of the electrically conductive layer toward the first surface and a second photoexcitation material layer in which a potential of the valence band maximum decreases from the second surface toward the first surface.

Abstract: A photochemical electrode includes: an electrically-conductive layer; and a photo-excited material layer including a photo-excited material provided over the electrically-conductive layer, wherein in a surface of the photo-excited material layer, a lattice plane having highest atomic density in a crystal structure of the photo-excited material is oriented in a surface direction of the surface of the photo-excited material layer.

Abstract: An oxygen generating electrode includes: an oxide film having a perovskite structure; an organic film over the oxide film; and a conductive film electrically coupled to the organic film, wherein the organic film contains an amino acid having a side chain of negative polarity.

Abstract: An oxygen generation electrode includes, a conductive layer including a salt of stannic acid, the salt of stannic acid having a perovskite structure, a light absorption layer disposed on the conductive layer, and a catalyst layer disposed on the light absorption layer, the catalyst layer including an oxide having a perovskite structure and being responsible for an oxygen evolution reaction, the conductive layer being doped to degeneracy with impurities, the light absorption layer forming a Type-II heterojunction with the conductive layer, the catalyst layer being doped to degeneracy with impurities, the upper end of the valence band of the catalyst layer being higher than the upper end of the valence band of the light absorption layer.

Abstract: A non-transitory computer-readable recording medium stores therein a design program for causing a computer to execute a process for designing a composition of a perovskite type crystal structure, the design program comprising causing a computer to determine a combination of Ai and Bi in the following formula (2) created by taking a logarithm of a formula of a tolerance factor (t) represented by the following formula (1), in which log t is 0 or close to 0, by executing ground state search by an annealing method using an Ising model or QUBO, t = ( r A + r X ) 2 ? ( r B + r X ) = d A ? - ? X 2 ? d B ? - ? X Formula ? ? ( 1 ) log ? ? t = ? i = 1 n ? A i - ? i = 1 n ? B i .

Abstract: A photochemical electrode includes: an optical absorption layer; a catalyst layer for oxygen evolution reaction over the optical absorption layer; and a conducting layer over the catalyst layer. A valance band maximum of the catalyst layer is higher than a valance band maximum of the optical absorption layer. A work function of the conducting layer is larger than a work function of the catalyst layer.

Abstract: A photochemical electrode includes: an electrically conductive layer; and a photoexcitation material layer provided over the electrically conductive layer and including a photoexcitation material, wherein the photoexcitation material layer is one of a first photoexcitation material layer in which a potential of the conduction band minimum decreases from a second surface opposite to a first surface on the side of the electrically conductive layer toward the first surface and a second photoexcitation material layer in which a potential of the valence band maximum decreases from the second surface toward the first surface.

Abstract: An oxygen evolution device comprises an oxygen evolution electrode and an counter electrode. The oxygen evolution electrode includes: a photocatalyst layer that is formed of a perovskite-type oxide containing at least cobalt (Co), lanthanum (La), and oxygen (O) and that is located at an uppermost layer; a support body that includes at least a layer inside which a depletion layer is formed, and that supports the photocatalyst layer; and a perovskite-type tin compound buffer layer that is degenerately doped n-type and that is disposed between the photocatalyst layer and the support body.

Abstract: A thermoelectric conversion element includes: a first layer of perovskite-type oxide has conductivity or semiconductivity; a second layer of perovskite-type oxide that is disposed in contact with the first layer in a stacking direction; and an electrode disposed on a surface of the second layer, wherein the second layer has a band gap larger than a band gap of the first layer and has transition lines penetrating through the second layer in a film thickness direction or a transition line network.

Abstract: An oxygen generating electrode includes a conductive layer; a photocatalyst layer; and a light absorption. The light-absorbing layer arranged between the conductive layer and the photocatalyst layer. The light-absorbing layer is formed of one or a plurality of perovskite-type films, and each of the films contains tin (Sn), oxygen (O), sulfur (S), and one or more elements selected from Group 1 or Group 2 of the periodic table of elements. Each of the films formed by doping S for substituting an O site is set so that a band gap takes a predetermined value in a range between 0 eV to 4 eV.

Abstract: A thermoelectric conversion element includes: a first film including a perovskite structure; a second film and a third film, including a perovskite structure, disposed in such a manner that the first film is interposed between the second film and the third film; a fourth film, including a perovskite structure, disposed so as to interpose the second film with the first film; and a fifth film, including a perovskite structure, disposed so as to interpose the third film with the first film, wherein an offset in conduction band between the first film and the second film and an offset in conduction band between the first film and the third film is less than 0.25 eV, and an offset in conduction band between the second film and the fourth film and an offset in conduction band between the third film and the fifth film is more than 1 eV.

Abstract: A photochemical electrode includes: an electrically-conductive layer; and a photo-excited material layer including a photo-excited material provided over the electrically-conductive layer, wherein in a surface of the photo-excited material layer, a lattice plane having highest atomic density in a crystal structure of the photo-excited material is oriented in a surface direction of the surface of the photo-excited material layer.

Abstract: A photochemical electrode includes a conductive oxide. Fermi energy of the conductive oxide is higher than a first energy minimum of a first band having a lowest energy and is lower than a second energy minimum of a second band having a higher energy than the first band among bands whose curvatures are positive in reciprocal space. The first energy minimum and the second energy minimum are at the same point of wave vector. A difference between the second energy minimum and the first energy minimum is not less than 1 eV nor more than 3 eV, and is smaller than a difference between the first energy minimum and an energy maximum of a band having a highest energy among bands whose curvatures are negative.

Abstract: An oxygen generation electrode includes: a conductive substrate; and an oxide film formed on a first surface of the conductive substrate and containing Ba, Sn, and La or Sb, wherein the oxide film has a first absorption edge in a visible light region and a second absorption edge in an infrared light region.

Abstract: A thermoelectric conversion element includes: a first layer of perovskite-type oxide has conductivity or semiconductivity; a second layer of perovskite-type oxide that is disposed in contact with the first layer in a stacking direction; and an electrode disposed on a surface of the second layer, wherein the second layer has a band gap larger than a band gap of the first layer and has transition lines penetrating through the second layer in a film thickness direction or a transition line network.

Abstract: An oxygen generating electrode includes: an oxide film having a perovskite structure; an organic film over the oxide film; and a conductive film electrically coupled to the organic film, wherein the organic film contains an amino acid having a side chain of negative polarity.

Abstract: A photoexcitable material includes: a solid solution of MN (where M is at least one of gallium, aluminum and indium) and ZnO, wherein the photoexcitable material includes 30 to 70 mol % ZnO and has a band gap energy of 2.20 eV or less.

Abstract: A photoexcitation material includes: a wurtzite type solid solution crystal containing t gallium, zinc, nitrogen and oxygen, wherein a peak (A) of an existence ratio of nitrogen or oxygen which is a first adjacent atom of the gallium or zinc and a peak (B) of an existence ratio of gallium or zinc which is a second adjacent atom of the gallium or zinc satisfy a relational expression of A>B in a relationship between a distance and the existence ratio of the adjacent atom of the gallium or zinc, the relationship being obtained from an extended X-ray absorption fine structure analysis.