The present disclosure relates to novel two-dimensional halide perovskite materials, and the method of making and using the two-dimensional halide perovskite materials.

A flexible thermoelectric structure is provided, which includes a porous thermoelectric pattern having a first surface and a second surface opposite to the first surface, and a polymer film covering the first surface of the porous thermoelectric pattern. The polymer film fills pores of the porous thermoelectric pattern. The polymer film has a first surface and a second surface opposite to the first surface. The second surface of the polymer film is coplanar with the second surface of the porous thermoelectric pattern.

A flexible thermoelectric structure is provided, which includes a porous thermoelectric pattern having a first surface and a second surface opposite to the first surface, and a polymer film covering the first surface of the porous thermoelectric pattern. The polymer film fills pores of the porous thermoelectric pattern. The polymer film has a first surface and a second surface opposite to the first surface. The second surface of the polymer film is coplanar with the second surface of the porous thermoelectric pattern.

A thermoelectric conversion material is constituted of a semiconductor that contains a constituent element and an additive element having a difference of 1 in the number of electrons in an outermost shell from the constituent element, the additive element having a concentration of not less than 0.01 at % and not more than 30 at %. The semiconductor has a microstructure including an amorphous phase and a granular crystal phase dispersed in the amorphous phase. The amorphous phase includes a first region in which the concentration of the additive element is a first concentration, and a second region in which the concentration of the additive element is a second concentration lower than the first concentration. The first concentration and the second concentration have a difference of not less than 15 at % and not more than 25 at % therebetween.

A thermoelectric conversion material is constituted of a semiconductor that contains a constituent element and an additive element having a difference of 1 in the number of electrons in an outermost shell from the constituent element, the additive element having a concentration of not less than 0.01 at % and not more than 30 at %. The semiconductor has a microstructure including an amorphous phase and a granular crystal phase dispersed in the amorphous phase. The amorphous phase includes a first region in which the concentration of the additive element is a first concentration, and a second region in which the concentration of the additive element is a second concentration lower than the first concentration. The first concentration and the second concentration have a difference of not less than 15 at % and not more than 25 at % therebetween.

Thermoelectric (TE) nanocomposite material that includes at least one component consisting of nanocrystals. A TE nanocomposite material in accordance with the present invention can include, but is not limited to, multiple nanocrystalline structures, nanocrystal networks or partial networks, or multi-component materials, with some components forming connected interpenetrating networks including nanocrystalline networks. The TE nanocomposite material can be in the form of a bulk solid having semiconductor nanocrystallites that form an electrically conductive network within the material. In other embodiments, the TE nanocomposite material can be a nanocomposite thermoelectric material having one network of p-type or n-type semiconductor domains and a low thermal conductivity semiconductor or dielectric network or domains separating the p-type or n-type domains that provides efficient phonon scattering to reduce thermal conductivity while maintaining the electrical properties of the p-type or n-type semiconductor.

Thermoelectric (TE) nanocomposite material that includes at least one component consisting of nanocrystals. A TE nanocomposite material in accordance with the present invention can include, but is not limited to, multiple nanocrystalline structures, nanocrystal networks or partial networks, or multi-component materials, with some components forming connected interpenetrating networks including nanocrystalline networks. The TE nanocomposite material can be in the form of a bulk solid having semiconductor nanocrystallites that form an electrically conductive network within the material. In other embodiments, the TE nanocomposite material can be a nanocomposite thermoelectric material having one network of p-type or n-type semiconductor domains and a low thermal conductivity semiconductor or dielectric network or domains separating the p-type or n-type domains that provides efficient phonon scattering to reduce thermal conductivity while maintaining the electrical properties of the p-type or n-type semiconductor.

A magnesium-based thermoelectric conversion material made of a sintered compact of a magnesium compound, in which, in a cross section of the sintered compact, a Si-rich metallic phase having a higher Si concentration than in magnesium compound grains is unevenly distributed in a crystal grain boundary between the magnesium compound grains, an area ratio of the Si-rich metallic phase is in a range of 2.5% or more and 10% or less, and a number density of the Si-rich metallic phase having an area of 1 μm.sup.2 or more is in a range of 1,800/mm.sup.2 or more and 14,000/mm.sup.2 or less.

A thermoelectric conversion material is constituted of a semiconductor that contains a constituent element and an additive element having a difference of 1 in the number of electrons in an outermost shell from the constituent element, the additive element having a concentration of not less than 0.01 at % and not more than 30 at %. The semiconductor has a microstructure including an amorphous phase and a granular crystal phase dispersed in the amorphous phase. The amorphous phase includes a first region in which the concentration of the additive element is a first concentration, and a second region in which the concentration of the additive element is a second concentration lower than the first concentration. The first concentration and the second concentration have a difference of not less than 15 at % and not more than 25 at % therebetween.

[Object] To provide a thermoelectric material that reduces, when a thermoelectric conversion module is formed therefrom, contact resistance with an electrode and will not be peeled; the thermoelectric conversion module using the thermoelectric material; a method of producing the same, and a Peltier device.

[Solving Means] A thermoelectric material according to the present invention includes a thermoelectric substance and a solvent, and the solvent has a vapor pressure of 0 Pa or more and 1.5 Pa or less at 25° C., has a storage elastic modulus G′ in a range of 1×10.sup.1 Pa or more and 4×10.sup.6 Pa or less, and has a loss elastic modulus G″ in a range of 5 Pa or more and 4×10.sup.6 Pa or less.